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1.
PLoS One ; 19(7): e0306540, 2024.
Article in English | MEDLINE | ID: mdl-38990867

ABSTRACT

With the rapid proliferation of portable and wearable electronics, energy autonomy through efficient energy harvesting has become paramount. Thermoelectric generators (TEGs) stand out as promising candidates due to their silent operation, high reliability, and maintenance-free nature. This paper presents the design, fabrication, and analysis of a micro-scale TEG for powering such devices. A planar configuration was employed for its inherent miniaturization advantages. Finite element analysis using ANSYS reveals that a double-layer device under a 50 K temperature gradient generates an impressive open-circuit voltage of 1417 mV and a power output of 2.4 µW, significantly exceeding its single-layer counterpart (226 mV, 0.12 µW). Validation against the analytical model results yields errors within 2.44% and 2.03% for voltage and power, respectively. Furthermore, a single-layer prototype fabricated using paper shadow masks and sputtering deposition exhibits a voltage of 131 mV for a 50 K temperature difference, thus confirming the feasibility of the proposed design. This work establishes a foundation for developing highly efficient micro-TEGs for powering next-generation portable and wearable electronics.


Subject(s)
Electric Power Supplies , Wearable Electronic Devices , Temperature , Equipment Design , Finite Element Analysis , Miniaturization , Electricity
2.
Sci Rep ; 14(1): 13105, 2024 Jun 07.
Article in English | MEDLINE | ID: mdl-38849420

ABSTRACT

A Virtual Power Plant (VPP) is a centralized energy system that manages, and coordinates distributed energy resources, integrating them into a unified entity. While the physical assets may be dispersed across various locations, the VPP integrates them into a virtual unified entity capable of responding to grid demands and market signals. This paper presents a tri-level hierarchical coordinated operational framework of VPP. Firstly, an Improved Pelican Optimization Algorithm (IPOA) is introduced to optimally schedule Distributed Energy Resources (DERs) within the VPP, resulting in a significant reduction in generation costs. Comparative analysis against conventional algorithms such as Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) demonstrates IPOA's superior performance, achieving an average reduction of 8.5% in generation costs across various case studies. The second stage focuses on securing the optimized generation data from rising cyber threats, employing the capabilities of machine learning, preferably, a convolutional autoencoder to learn the normal patterns of the optimized data to detect deviations from the optimized generation data to prevent suboptimal decisions. The model exhibits exceptional performance in detecting manipulated data, with a False Positive Rate (FPR) of 1.92% and a Detection Accuracy (DA) of 98.06%, outperforming traditional detection techniques. Lastly, the paper delves into the dynamic nature of the day ahead market that the VPP participates in. In responding to the grid by selling its optimized generated power via the day-ahead market, the VPP employs the Prophet model, another machine learning technique to forecast the spot market price for the day-ahead to mitigate the adverse effects of price volatility. By utilizing Prophet forecasts, the VPP achieves an average revenue increase of 15.3% compared to scenarios without price prediction, emphasizing the critical role of predictive analytics in optimizing economic gains. This tri-level coordinated approach adopted addresses key challenges in the energy sector, facilitating progress towards achieving universal access to clean and affordable energy.

3.
Cureus ; 16(4): e58426, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38765358

ABSTRACT

Introduction Acute Coronary Syndrome (ACS) is a critical condition characterized by reduced blood flow to the heart and includes various conditions such as ST-elevation myocardial infarction, non-ST elevation myocardial infarction, and unstable angina. Objectives The aim of this study was to investigate age-related patterns of symptoms and risk factors in ACS patients and to evaluate how diagnostic test results differ among various age groups of ACS patients. Methodology This retrospective study was conducted from May to November of 2023 on patients with acute coronary syndrome admitted to the cardiology ward of Rehman Medical Institute (RMI), Peshawar. The sample size was 137 ACS-diagnosed patients based on the inclusion and exclusion criteria. After getting ethical approval from the institutional ethical approval board, data were collected for the entire year of 2022 based on proforma with the variables demographic data, troponin I level, presented symptoms, and associated co-morbidities of the patients. The inclusion criteria were patients of all genders, patients diagnosed with Acute Coronary Syndrome (ACS), and patients whose records were available in the cardiology department of Rehman Medical Institute.  Results The results show that ACS is more prevalent in the age group of 50-69 years (p=0.037) and is significantly more common in males (p=0.019). Chest pain emerged as the predominant symptom, with a significant association of p=0.029 between chest pain and patients of ACS in the age group 30-49 years. While raised troponin I levels were prevalent across all age groups. Moreover, specific risk factors such as diabetes mellitus, hypertension, and family history of CAD showed the significance of p= 0.04, p=0.006, and p=0.021, respectively, with the age group 50-69 years old. Conclusion This study highlights the importance of considering age and gender in ACS management and provides insights into age-related patterns of symptoms and risk factors, which can contribute to optimizing preventive strategies and improving patient care. Further research is needed to explore the underlying mechanisms and assess long-term outcomes in different age groups.

4.
Cureus ; 15(6): e40587, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37469814

ABSTRACT

Heart failure, a complex cardiovascular condition, is a huge burden on patients, caregivers, and healthcare systems and it is prevalent worldwide. Heart failure is caused by a wide variety of underlying conditions that include both cardiac and non-cardiac pathologies. Identifying the underlying cause enables us to apply etiology-based interventions. The spectrum of heart failure management ranges from classification to transplantation. In addition to its classification and monitoring, this article reviews various management strategies, including both conventional methods and the latest innovations. These include lifestyle interventions, pharmacotherapy, device therapy, transplantation, and regenerative medicine.

5.
Cureus ; 15(6): e39873, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37404395

ABSTRACT

Exercise is widely considered beneficial for cardiovascular health. However, on rare occasions, athletes experience sudden cardiac death without any preceding symptoms. The devastating nature of these events necessitates us to understand the underlying causes. In younger athletes (age <35), the underlying causes are usually hereditary/genetic, whereas in older athletes (age >35), coronary artery disease is prevalent. Sudden cardiac death in athletes can occur regardless of the presence of any structural abnormality in the heart. Despite divergence between guidelines, the majority of cardiology societies recommend at least taking a comprehensive history and performing physical examinations for initial screening for all athletes. This article reviews the consensuses and controversies regarding the incidence, causes, and prevention of sudden cardiac death in athletes.

6.
Cureus ; 15(3): e35812, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37033524

ABSTRACT

Kommerell's diverticulum is an embryologic developmental anomaly of the aortic arch wherein a diverticulum arises from either the left or the right aortic arch. It results due to the persistence of the remnant of the fourth dorsal aortic arch. We present a case of a 66-year-old female presenting with complaints of throat pain and difficulty swallowing. A computed tomography (CT) scan of the neck with contrast revealed an incidental finding of an aberrant right subclavian artery with associated diverticula of Kommerell, measuring up to 1 cm, causing a mass effect on the esophagus and posterior trachea. A diagnosis of dysphagia lusoria was established, and an upper gastrointestinal (GI) series revealed narrowing of the esophagus from posterior extrinsic compression. The patient was discharged home for nutrition optimization with a percutaneous endoscopic gastrostomy (PEG) tube due to significant weight loss from the inability to swallow before proceeding with surgery to repair the aberrant right subclavian artery.

7.
Cureus ; 15(3): e36039, 2023 Mar.
Article in English | MEDLINE | ID: mdl-37056547

ABSTRACT

Thrombotic thrombocytopenic purpura (TTP) is a rare and potentially devastating blood disorder depicted by thrombocytopenia, fever, widespread small vessel hemolytic anemia, and neurological symptoms. The involvement of the renal and neurological systems is frequently reported in TTP; however, TTP-induced acute coronary syndrome is not widely reported. We describe a case of myocardial infarction induced by TTP in a patient who presented with the typical manifestation of acute coronary syndrome. Echocardiogram revealed a myocardial injury, and detailed investigations revealed increased levels of troponin I, lactate dehydrogenase, diminished levels of haptoglobin and von Willebrand factor-cleaving protease, and schistocytes on peripheral smear, suggestive of TTP-induced myocardial infarction. His condition was stabilized after commencing plasmapheresis, steroids, and rituximab. The initial steps in the management of this patient involve the prompt administration of steroids and the urgent start of plasmapheresis to increase platelet count.

8.
J Bacteriol ; 203(19): e0036021, 2021 09 08.
Article in English | MEDLINE | ID: mdl-34280003

ABSTRACT

Lactobacillus crispatus is a well-established probiotic with antimicrobial activity against pathogens across several niches of the human body generally attributed to the production of bacteriostatic molecules, including hydrogen peroxide and lactic acid. Here, we show that the cell-free supernatants of clinical isolates of L. crispatus harbor robust bactericidal activity. We further identify phenyl-lactic acid as a bactericidal compound with properties and a susceptibility range nearly identical to that of the cell-free supernatant. As such, we hypothesize that phenyl-lactic acid is a key active ingredient in L. crispatus supernatant. IMPORTANCE Although Lactobacillus crispatus is an established commensal microbe frequently used in probiotics, its protective role in the bladder microbiome has not been clarified. We report here that some urinary isolates of L. crispatus exhibit bactericidal activity, primarily due to its ability to excrete phenyl-lactic acid into its environment. Both cell-free supernatants of L. crispatus isolates and phenyl-lactic acid exhibit bactericidal activity against a wide range of pathogens, including several that are resistant to multiple antibiotics.


Subject(s)
Anti-Infective Agents/chemistry , Anti-Infective Agents/pharmacology , Lactates/metabolism , Lactates/pharmacology , Lactobacillus crispatus/metabolism , Anti-Infective Agents/metabolism , Bacteria/drug effects , Candida/drug effects , Lactates/chemistry
9.
Proc Natl Acad Sci U S A ; 114(50): E10707-E10716, 2017 12 12.
Article in English | MEDLINE | ID: mdl-29180435

ABSTRACT

Numerous viruses, including HIV-1, exploit the microtubule network to traffic toward the nucleus during infection. Although numerous studies have observed a role for the minus-end microtubule motor dynein in HIV-1 infection, the mechanism by which the viral core containing the viral genome associates with dynein and induces its perinuclear trafficking has remained unclear. Here, we report that the dynein adapter protein bicaudal D2 (BICD2) is able to interact with HIV-1 viral cores in target cells. We also observe that BICD2 can bind in vitro-assembled capsid tubes through its CC3 domain. We observe that BICD2 facilitates infection by promoting the trafficking of viral cores to the nucleus, thereby promoting nuclear entry of the viral genome and infection. Finally, we observe that depletion of BICD2 in the monocytic cell line THP-1 results in an induction of IFN-stimulated genes in these cells. Collectively, these results identify a microtubule adapter protein critical for trafficking of HIV-1 in the cytoplasm of target cells and evasion of innate sensing mechanisms in macrophages.


Subject(s)
Genome, Viral , HIV Infections/metabolism , HIV-1/genetics , Microtubule-Associated Proteins/metabolism , Active Transport, Cell Nucleus , Capsid/metabolism , Cell Nucleus/virology , Cytoplasm/virology , Gene Knockout Techniques , HEK293 Cells , HIV Infections/virology , HIV-1/immunology , HIV-1/metabolism , HeLa Cells , Humans , Macrophages/immunology , Microtubule-Associated Proteins/genetics , Virus Internalization , Virus Replication , Virus Uncoating
10.
J Phys Chem B ; 118(11): 3183-91, 2014 Mar 20.
Article in English | MEDLINE | ID: mdl-24558952

ABSTRACT

Electrochemical reduction of cis-stilbene occurs by two well-resolved one-electron reduction steps in acetonitrile with (n-Bu)4NPF6 as the supporting electrolyte and in N-butyl-N-methylpyrrolidinium (Pyrr1,4(+)) and (trimethylamine)(dimethylethylamine)-dihydroborate bis(trifluoromethylsulfonyl)amide (NTf2(-)) ionic liquids (ILs). Mechanistic details of the electroreduction have been probed by dc and Fourier transformed ac voltammetry, simulation of the voltammetry, bulk electrolysis, and EPR spectroscopy. The first one-electron reduction induces fast cis to trans isomerization in CH3CN and ILs, most likely occurring via disproportionation of cis-stilbene radical anions and fast transformation of the cis-dianion to the trans-configuration. The second reduction process is chemically irreversible in CH3CN due to protonation of the dianion but chemically reversible in highly aprotic ILs under high cis-stilbene concentration conditions. Increase of the (n-Bu)4NPF6 supporting electrolyte concentration (0.01-1.0 M) in CH3CN induces substantial positive shifts in the potentials for reduction of cis-stilbene, consistent with strong ion pairing of the anion radical and dianion with (n-Bu)4N(+). However, protection by ion pairing against protonation of the stilbene dianions or electrochemically induced cis-trans-stilbene isomerization is not achieved. Differences in electrode kinetics and reversible potentials for cis-stilbene(0/•-) and trans-stilbene(0/•-) processes are less pronounced in the Pyrr1,4-NTf2 ionic liquid than in the molecular solvent acetonitrile.

11.
Anal Chem ; 85(12): 6113-20, 2013 Jun 18.
Article in English | MEDLINE | ID: mdl-23659207

ABSTRACT

Three highly aprotic bis(trifluoromethylsulfonyl)amide (NTf2(-)) based ionic liquids (ILs) containing the cations trihexyl(tetradecyl)phosphonium (P6,6,6,14(+)), N-butyl-N-methylpyrrolidinium (Pyrr4,1(+)), and (trimethylamine)(dimethylethylammine)dihydroborate ((N111)(N112)BH2(+)) have been examined as media for room temperature voltammetric detection of highly basic stilbene dianions electrochemically generated by the reduction of trans-stilbene (t-Stb) and its derivatives (4-methoxy-, 2-methoxy-, 4,4'-dimethyl-, and 4-chloromethyl-). Transient and steady-state data in the ILs were compared with results obtained in the molecular solvent acetonitrile. In all media examined, the t-Stb(0/•-) process is chemically and electrochemically reversible with a heterogeneous charge transfer rate constant in CH3CN of 1.5 cm s(-1), as determined by Fourier transformed AC voltammetry. However, further reduction to the dianion was always irreversible in this molecular but weakly acidic solvent. On the other hand, a substantial level of chemical reversibility for the reduction of t-Stb(•-) to t-Stb(2-) on the time scale of cyclic voltammetry is achieved when the concentration of trans-stilbene, [t-Stb], appreciably exceeds the concentration of adventitious water or other proton sources. In particular, these conditions are met when [t-Stb] ≥ 0.1 M in thoroughly dehydrated and purified ILs, while in the presence of CH3CN, t-Stb(2-) still suffers fast irreversible protonation under these stilbene concentration conditions. The E0/•-(0) values (vs Fc(0/+)) for substituted trans-stilbenes in acetonitrile and (N111)(N112)BH2-NTf2 do not differ substantially, nor do the E0/•-(0) and E•-/2-(0) differences or other aspects of the voltammetric behavior.

12.
Appl Spectrosc ; 61(10): 1103-6, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17958961

ABSTRACT

Measurements of near-infrared scattered circular polarization Raman optical activity (SCP-ROA) are presented using laser excitation at 780 nm for samples of S-(-)-alpha-pinene and L-alanyl-L-alanine. These are the first measurements of ROA outside the blue-to-green visible region between 488 and 532 nm. Comparison of Raman and ROA intensities measured with excitation at 532 and 780 nm demonstrate that the expected frequency to the fourth-power dependence for Raman scattering and the corresponding fifth-power dependence for ROA are observed. It can be concluded that, to within this frequency dependence, the same level of efficiency of Raman and ROA measurements using commercial instrumentation with 532 nm excitation is maintained with the change to near-infrared excitation at 780 nm.


Subject(s)
Spectrophotometry, Infrared/methods , Spectrum Analysis, Raman/methods , Reproducibility of Results , Sensitivity and Specificity
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