Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 19 de 19
Filter
Add more filters










Publication year range
1.
Chem Sci ; 14(23): 6383-6392, 2023 Jun 14.
Article in English | MEDLINE | ID: mdl-37325136

ABSTRACT

The essence of any electrochemical system is engraved in its electrical double layer (EDL), and we report its unprecedented reorganization by the structural isomerism of molecules, with a direct consequence on their energy storage capability. Electrochemical and spectroscopic analyses in combination with computational and modelling studies demonstrate that an attractive field-effect due to the molecule's structural-isomerism, in contrast to a repulsive field-effect, spatially screens the ion-ion coulombic repulsions in the EDL and reconfigures the local density of anions. In a laboratory-level prototype supercapacitor, those with ß-structural isomerism exhibit nearly 6-times elevated energy storage compared to the state-of-the-art electrodes, by delivering ∼535 F g-1 at 1 A g-1 while maintaining high performance metrics even at a rate as high as 50 A g-1. The elucidation of the decisive role of structural isomerism in reconfiguring the electrified interface represents a major step forward in understanding the electrodics of molecular platforms.

2.
Sci Rep ; 13(1): 8316, 2023 May 23.
Article in English | MEDLINE | ID: mdl-37221203

ABSTRACT

Hybrid nanofluid are the modified class of nanofluids with extra high thermal performances and present different applications in automotive cooling, heat transfer devices, solar collectors, engine applications, fusion processes, machine cutting, chemical processes etc. This thermal research explores the heat transfer assessment due to hybrid nanofluid with of different shape features. The thermal inspections regarding the hybrid nanofluid model are justified with aluminium oxide and titanium nanoparticles. The base liquid properties are disclosed with ethylene glycol material. The novel impact of current model is the presentation of different shape features namely Platelets, blade and cylinder. Different thermal properties of utilized nanoparticles at various flow constraints are reported. The problem of hybrid nanofluid model is modified in view of slip mechanism, magnetic force and viscous dissipation. The heat transfer observations for decomposition of TiO2-Al2O3/C2H6O2 is assessed by using the convective boundary conditions. The shooting methodology is involved for finding the numerical observations of problem. Graphical impact of thermal parameters is observed for TiO2-Al2O3/C2H6O2 hybrid decomposition. The pronounced observations reveal that thermal rate enhanced for blade shaped titanium oxide-ethylene glycol decomposition. The wall shear force reduces for blade shaped titanium oxide nanoparticles.

3.
Anal Chem ; 92(6): 4541-4547, 2020 03 17.
Article in English | MEDLINE | ID: mdl-32067452

ABSTRACT

We report the independent role of isomerism of secondary sphere substituents over their nature, a factor often overlooked in molecular electrocatalysis pertaining to electrochemical sensing, by establishing that isomerism redefines the electronic structure at the catalytic reaction center via geometrical factors. UV-vis spectroscopy and X-ray photoelectron spectroscopy suggest that a substituent's isomerism in molecular catalysts conjoins molecular planarity and catalytic activation through competing field effects and resonance effects. As a classical example, we demonstrate the influence of isomerism of the -NO2 substituents for the electrocatalytic multi electron oxidation of As(III), a potentially important electrochemical pathway for water remediation and arsenic detection. The isomerism dependent oxidative activation of catalytic center leads to a nonprecious molecular catalyst capable for direct As(III) oxidation with an experimental detection limit close to WHO guidelines. This work opens up an unusual approach in analytical chemistry for developing various sensing platforms for challenging chemical and electrochemical reactions.


Subject(s)
Arsenic/analysis , Cobalt/chemistry , Electrochemical Techniques , Nitrogen Dioxide/chemistry , Organometallic Compounds/chemistry , Catalysis , Electrons , Isomerism , Molecular Structure , Oxidation-Reduction , Particle Size , Quartz Crystal Microbalance Techniques , Surface Properties
4.
J Colloid Interface Sci ; 559: 324-330, 2020 Feb 01.
Article in English | MEDLINE | ID: mdl-31675663

ABSTRACT

Hydrogen peroxide is a commodity chemical with immense applications as an environmentally benign disinfectant for water remediation, a green oxidant for synthetic chemistry and pulp bleaching, an energy carrier molecule and a rocket propellant. It is typically synthesized by indirect batch anthraquinone process, where sequential hydrogenation and oxidation of anthraquinone molecules generates H2O2. This highly energy demanding catalytic sequence necessitates the advent of new reaction pathways with lower energy expenditure. Here we demonstrate a Zn-quinone battery for paired H2O2 electrosynthesis at the three phase boundary of its cathodic half-cell during electric power generation. The catalytic quinone half-cell of the Zn-quinone battery, mediates proton coupled electron transfer with molecular oxygen during its chemical regeneration thereby pairing peroxide electrosynthesis with electricity generation. Hydrogen peroxide synthesizing Zn-quinone battery (HPSB) demonstrated a peak power density of ~90 mW/cm2 at a peak current density of ~145 mA/cm2 while synthesizing ~230 mM of H2O2. HPSB offers immense opportunities as it distinctly couples electric power generation with peroxide electrosynthesis which in-turn transforms energy conversion in batteries truly multifunctional.

5.
J Phys Chem Lett ; 8(15): 3523-3529, 2017 Aug 03.
Article in English | MEDLINE | ID: mdl-28686441

ABSTRACT

Molecular oxygen, the conventional electron acceptor in fuel cells poses challenges specific to direct alcohol fuel cells (DAFCs). Due to the coupling of alcohol dehydrogenation with the scission of oxygen on the positive electrode during the alcohol crossover, the benchmark Pt-based air cathode experiences severe competition and depolarization losses. The necessity of heavy precious metal loading with domains for alcohol tolerance in the state of the art DAFC cathode is a direct consequence of this. Although efforts are dedicated to selectively cleave oxygen, the root of the problem being the inner sphere nature of either half-cell chemistry is often overlooked. Using an outer sphere electron acceptor that does not form a bond with the cathode during redox energy transformation, we effectively decoupled the interfacial chemistry from parasitic chemistry leading to a DAFC driven by alcohol passive carbon nanoparticles, with performance metrics ∼8 times higher than Pt-based DAFC-O2.

6.
Article in English | WPRIM (Western Pacific) | ID: wpr-174369

ABSTRACT

In the present study we evaluated the anti-inflammatory potential of 3-hydroxy-4,7-megastigmadien-9-one (Comp) isolated from Ulva pertusa Kjellman, in LPS-stimulated bone marrow-derived dendritic cells (BMDCs). Comp treatment exhibited strong dose dependent inhibition of IL-12 p40 and IL-6 cytokine production with IC₅₀ values of 7.85 ± 0.32 and 7.86 ± 0.18, respectively in LPS-stimulated BMDCs. Treatment of Comp inhibited MAPKs and NF-κB pathways in LPS-stimulated BMDCs by inhibiting the phosphorylation of ERK1/2, JNK1/2, p38 and IκB. Thus, these results suggest that Comp have a significant anti-inflammatory property and affirm further studies concerning the potentials of Comp for medicinal use.


Subject(s)
Dendritic Cells , Interleukin-12 , Interleukin-6 , Phosphorylation , Protein Kinases , Ulva
7.
Article in English | WPRIM (Western Pacific) | ID: wpr-195571

ABSTRACT

Marine algae exhibit broad spectrum anti-bacterial and anti-inflammatory activities. Acrosorium polyneurum (A. polyneurum) is a marine red alga and belongs to the family Delesseriaceae. The present research evaluates the antiinflammatory effects of A. polyneurum extract (APE) on pro-inflammatory cytokine production. APE demonstrated substantial inhibitory effects on production of pro-inflammatory cytokine in bone marrow-derived macrophages (BMDMs). APE pre-treatment in the lipopolysaccharide (LPS)-stimulated BMDMs exhibited a robust inhibitory effect on production of interleukin (IL)-12, IL-6 and tumor necrosis factor (TNF)-α. It revealed a robust inhibitory effect on phosphorylation of ERK1/2, JNK1/2 and p38. APE also showed remarkable inhibitory effect on phosphorylation and degradation of IκBα. Furthermore, APE pre-treatment demonstrated substantial inhibition of LPS-induced production of nitric oxide and inducible nitric oxide synthase. Collectively, these data suggest that APE has a noteworthy anti-inflammatory property and deserve further studies concerning its potential use as a medicinal agent for inflammation-related disorders.


Subject(s)
Humans , Hominidae , Interleukin-6 , Interleukins , Macrophages , Nitric Oxide , Nitric Oxide Synthase Type II , Phosphorylation , Tumor Necrosis Factor-alpha
8.
Article in English | WPRIM (Western Pacific) | ID: wpr-195569

ABSTRACT

Childhood malnutrition is a global problem and one of the leading cause of stunted growth, and responsible for the death of millions of children every year. Although extensive efforts have been made to promote healthy growth but results are not satisfactory and infant's health remains a challenge. Previously, it was demonstrated that undernourished children have disrupted normal pattern of intestinal microbiota and led to a proposal that it might be involved in impaired postnatal growth. Recently, various research groups focused on Malawian population and proved the role of intestinal microbiota in the stunted growth of children. In addition, one group showed the role of sialylated bovine milk oligosaccharides in promoting microbiota-dependent growth in malnourished children. Moreover, it was also revealed that Clostridium symbiosum and Ruminococcus gnavus might be used as therapeutic agent for ameliorating growth abnormalities in malnourished children. The current article summarizes the recent advancement in identifying interventions regarding health promotion of malnourished children.


Subject(s)
Child , Humans , Clostridium symbiosum , Gastrointestinal Microbiome , Growth Disorders , Health Promotion , Malnutrition , Microbiota , Milk , Oligosaccharides , Ruminococcus
9.
Trop Biomed ; 32(1): 11-6, 2015 Mar.
Article in English | MEDLINE | ID: mdl-25801250

ABSTRACT

Poultry farming not only provides high nutritious food but also creates employment opportunity for rural masses. Documented evidences elaborates that helminth parasitism is most deciduous problem of chickens especially in developing world. Ascaridia (A.) galli, a nematode of small intestine, has been considered as the most common and important parasite of chicken. The present study was carried out to investigate prevalence and severity of A. galli in White Leghorn layers (housing type: battery cage and deep litter, 50 each) and Fayoumi-Rhode Island Red crossbred (male and female: 50 each) flock rearing at Government Poultry Farm, Dina, Punjab, Pakistan. Two hundred faecal samples were examined by using standard parasitological and McMaster egg counting technique. The overall prevalence was 24.5% at farm, 13% in White leghorn layer (battery cage=2%, deep litter=24%) and 36% in Fayoumi-Rhode Island Red (male=34%, female=38%). It was also observed that White leghorn layer rearing in deep litter had more severe infection (EPG=1920) of A. galli compare with battery cages birds (EPG=500). Parasite prevalence was significantly related with sex (P<0.05) in Fayoumi-Rhode Island Red and male birds had less number of average parasites (0.34±0.47) as compared to females (0.38±0.490). Additionally, female birds were under serious threat of infection (EPG=2270) compared with its counterpart (EPG=1250). Given the high infection rates, particular attention should be paid to management and provision of feed supplement to White leghorn layer housing in deep litter and female bird of Fayoumi-Rhode Island Red crossbred.


Subject(s)
Ascaridia/isolation & purification , Ascaridiasis/veterinary , Poultry Diseases/epidemiology , Poultry Diseases/parasitology , Animals , Ascaridiasis/epidemiology , Ascaridiasis/parasitology , Ascaridiasis/pathology , Chickens , Feces/parasitology , Female , Male , Pakistan/epidemiology , Parasite Egg Count , Poultry Diseases/pathology , Prevalence
10.
Tropical Biomedicine ; : 11-16, 2015.
Article in English | WPRIM (Western Pacific) | ID: wpr-630409

ABSTRACT

Poultry farming not only provides high nutritious food but also creates employment opportunity for rural masses. Documented evidences elaborates that helminth parasitism is most deciduous problem of chickens especially in developing world. Ascaridia (A.) galli, a nematode of small intestine, has been considered as the most common and important parasite of chicken. The present study was carried out to investigate prevalence and severity of A. galli in White Leghorn layers (housing type: battery cage and deep litter, 50 each) and Fayoumi-Rhode Island Red crossbred (male and female: 50 each) flock rearing at Government Poultry Farm, Dina, Punjab, Pakistan. Two hundred faecal samples were examined by using standard parasitological and McMaster egg counting technique. The overall prevalence was 24.5% at farm, 13% in White leghorn layer (battery cage=2%, deep litter=24%) and 36% in Fayoumi-Rhode Island Red (male=34%, female=38%). It was also observed that White leghorn layer rearing in deep litter had more severe infection (EPG=1920) of A. galli compare with battery cages birds (EPG=500). Parasite prevalence was significantly related with sex (P<0.05) in Fayoumi-Rhode Island Red and male birds had less number of average parasites (0.34±0.47) as compared to females (0.38±0.490). Additionally, female birds were under serious threat of infection (EPG=2270) compared with its counterpart (EPG=1250). Given the high infection rates, particular attention should be paid to management and provision of feed supplement to White leghorn layer housing in deep litter and female bird of Fayoumi-Rhode Island Red crossbred.

11.
Article in English | WPRIM (Western Pacific) | ID: wpr-51197

ABSTRACT

Rheumatoid arthritis is an autoinflammatory disease that primarily affects joints and is characterized by pervasive joint inflammation. A20/Tumor necrosis factor, alpha-induced protein 3 (Tnfaip3) inhibits activation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB) and has been associated with rheumatoid arthritis. However, the precise role of A20 in rheumatoid arthritis remains unclear. Deletion of A20/Tnfaip3 gene in mice elicits impulsive erosive polyarthritis that is similar to rheumatoid arthritis in patients. Recently, it has been shown that A20 protects against arthritis by regulating the NLRP3 inflammasome.


Subject(s)
Animals , Humans , Mice , Arthritis , Arthritis, Rheumatoid , B-Lymphocytes , Inflammation , Joints , Necrosis
12.
Article in English | WPRIM (Western Pacific) | ID: wpr-112741

ABSTRACT

Marine algae are rich sources of various biologically active compounds with potential pharmaceutical properties. In the present study, we investigated the inhibitory effects of Plocamium telfairiae extract (PTE) on proinflammatory cytokine production in bone marrow-derived macrophage (BMDMs) and dendritic cells (BMDCs). PTE pre-treatment in LPS-stimulated BMDMs and BMDCs showed a strong inhibition on interleukin (IL)-12 p40, IL-6, and tumor necrosis factor (TNF)-alpha production as compared to non-treated controls. PTE pre-treatment showed significant inhibition on phosphorylation of mitogen-activated protein kinases and degradation of inhibitor of kappa B (IkappaBalpha). Taken together, these results suggest that PTE may have potential anti-inflammatory property and hence, warrant further studies concerning the potentials of PTE for medicinal purpose.


Subject(s)
Dendritic Cells , Inflammation , Interleukin-6 , Interleukins , Macrophages , Mitogen-Activated Protein Kinases , Phosphorylation , Plocamium , Tumor Necrosis Factor-alpha
13.
Article in English | WPRIM (Western Pacific) | ID: wpr-112738

ABSTRACT

Cyclic guanosine monophosphate-adenosine monophosphate (cGAMP) synthase (cGAS) is a cytosolic DNA sensor that plays an important role in innate immunity. Transfection of DNA or DNA virus infection results in the induction of type I interferon production in fibroblasts, macrophages, and dendritic cells which is dependent on cGAS. Recently, cGas (-/-) mice have been reported to be more vulnerable to fatal infection with herpes simplex virus 1 (HSV1) as compared to wild-type mice.


Subject(s)
Animals , Mice , Cytosol , Dendritic Cells , DNA , DNA Virus Infections , Fibroblasts , Guanosine , Herpesvirus 1, Human , Immunity, Innate , Interferon Type I , Macrophages , Transfection
14.
Article in English | WPRIM (Western Pacific) | ID: wpr-51113

ABSTRACT

The role of mitogen-activated protein kinases (MAPKs) in regulation of inflammation is well known. MAPK family is activated by various stimuli and involved in transmitting extracellular signals to nucleus leading to gene regulation. Inflammation is primary defensive response of host against microbes. Controlled inflammation is helpful and indispensable for host defense. However, uncontrolled inflammatory response leads to various inflammatory diseases and cancer. Persistent inflammation leads to cell proliferation and survival that plays crucial role in tumorigenesis. In this review, we recapitulate the recent knowledge of MAPK signaling and its roles in inflammation-associated carcinogenesis.


Subject(s)
Humans , Carcinogenesis , Cell Proliferation , Inflammation , Mitogen-Activated Protein Kinases , Protein Kinases
15.
Article in English | WPRIM (Western Pacific) | ID: wpr-117656

ABSTRACT

Detection of pathogen by pattern recognition receptors leads to activation of inflammasome which plays a crucial role in immune system. The inflammasome regulates the release of cytokines, such as interleukin (IL)-1beta, IL-18 and high-mobility group box 1 (HMGB1). Double-stranded RNA-dependent protein kinase (PKR) is a critical component of an inflammatory complex. Recently, the critical role of PKR was reported in regulation of multiple inflammasomes.


Subject(s)
Cytokines , eIF-2 Kinase , Immune System , Inflammasomes , Interleukin-18 , Interleukins , Receptors, Pattern Recognition
16.
Article in English | WPRIM (Western Pacific) | ID: wpr-87590

ABSTRACT

Nucleotide-binding and oligomerization domain (NOD)-like receptors (NLRs) play important role in immune responses by regulating nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kappaB), type I interferon and inflammasomes. Nod-like receptor pyrin domain-containing protein 6 (NLRP6) is vital for protection of mice from colitis and colorectal tumorigenesis. However, the role of NLRP6 in microbial infection remains unclear. NLRP6 was recently reported as negative regulator of inflammatory signaling and demonstrated that how it hinders clearance of bacterial pathogens.


Subject(s)
Animals , Mice , B-Lymphocytes , Cell Transformation, Neoplastic , Colitis , Cytoskeletal Proteins , Immunity, Innate , Inflammasomes , Interferon Type I , Listeria monocytogenes
17.
Article in English | WPRIM (Western Pacific) | ID: wpr-209796

ABSTRACT

Toll-like receptors are required for detection of pathogen-associated molecular patterns and play critical roles in protection of host from infection. Murine TLR13 was recently reported to be involved in recognition of bacterial 23S ribosomal RNA sequence that is the binding site of different antibiotics.


Subject(s)
Anti-Bacterial Agents , Binding Sites , RNA, Ribosomal, 23S , Staphylococcus aureus , Toll-Like Receptors
18.
Article in English | WPRIM (Western Pacific) | ID: wpr-43861

ABSTRACT

Murine caspase-11 is orthologus to human caspase-4 and caspase-5, and is required for the response to cholera toxin B and infection with Escherichia coli, Citrobacter rodentium or Vibrio cholerae. Caspase-11 rather than caspase-1 is the main offender involved in sepsis. Hence, caspase-11 plays an essential pro-inflammatory role in innate immune response to bacterial infections.


Subject(s)
Humans , Bacterial Infections , Cholera Toxin , Citrobacter rodentium , Criminals , Escherichia coli , Immunity, Innate , Sepsis , Vibrio cholerae
19.
Article in English | WPRIM (Western Pacific) | ID: wpr-200179

ABSTRACT

Mitogen-activated protein kinases (MAPKs) play critical regulatory roles in the production of the pro-inflammatory cytokines and downstream signaling events which lead to inflammation. Inflammation is a primarily localized and protective response of host against microbial infection. Controlled inflammation is beneficial and necessary for host defense while uncontrolled inflammatory response results in inflammatory diseases such as septic shock, rheumatoid arthritis and cancer. The MAPK family consists of three subfamilies; the extracellular signal-regulated kinases (ERKs), the c-Jun N-terminal kinases (JNKs), and the p38 MAPKs. MAPKs are involved in transmitting extracellular signals to nucleus which leads to gene regulation. In this review, we summarize the current knowledge of ERK1/2, JNKs, and p38 MAPK members and their roles in inflammation.


Subject(s)
Humans , Arthritis, Rheumatoid , Cytokines , Extracellular Signal-Regulated MAP Kinases , Inflammation , Mitogen-Activated Protein Kinases , p38 Mitogen-Activated Protein Kinases , Phosphotransferases , Shock, Septic
SELECTION OF CITATIONS
SEARCH DETAIL
...