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1.
PLoS One ; 19(6): e0304147, 2024.
Article in English | MEDLINE | ID: mdl-38861564

ABSTRACT

BACKGROUND: Colorectal cancer (CRC) is a cancer type that is thought to be influenced by human papillomaviruses (HPVs) and human polyomaviruses (HPyVs). In Egypt, CRC ranks as the 7th most common cancer, accounting for 3.47% of male cancers and 3% of female cancers. However, there is currently a lack of information regarding the presence of PyVs and HPVs co-infection specifically in CRC cases in Egypt. Therefore, the aim of this study was to investigate the occurrence of HPVs and HPyVs (JCPyV, BKPyV, and SV40) infections, as well as co-infections, among CRC patients in Egypt. Additionally, the study aimed to assess any potential association between these viral infections and tumor stages. METHODS: In the present study, we analyzed a total of 51 tissue samples obtained from Egyptian CRC patients, along with 19 polyps' samples. Our investigation focused on the detection and genotyping of HPyVs using Real-Time PCR. Additionally, we employed real-time PCR for the detection of HPVs, and for their genotyping, we utilized a combination of PCR amplification followed by sequencing. RESULTS: In our study, we found evidence of HPyVs infection in the CRC patients, specifically SV40 (25.5%) and BKPyV (19.6%). However, JCPyV was not detected in the samples that were examined. Additionally, we discovered that HPV was present in 43.1% of the CRC patients. When considering viral co-infections, 19.6% of the CRC samples showed coexistence of multiple viruses, while no co-infections were found in the polyps samples. Importantly, we observed a significant correlation between the presence of HPVs and advanced colorectal tumor grades B2 and D. CONCLUSION: Our findings provide valuable data for the detection of oncogenic viruses in colorectal cancer (CRC) and underscore the association of viral co-infections with advanced tumor stages. However, further research with larger cohorts is necessary to validate these findings and strengthen their significance in the field of CRC.


Subject(s)
Colorectal Neoplasms , Papillomaviridae , Papillomavirus Infections , Polyomavirus Infections , Polyomavirus , Humans , Colorectal Neoplasms/virology , Egypt/epidemiology , Female , Male , Middle Aged , Polyomavirus Infections/virology , Polyomavirus Infections/epidemiology , Polyomavirus Infections/complications , Papillomavirus Infections/virology , Papillomavirus Infections/epidemiology , Papillomavirus Infections/complications , Polyomavirus/isolation & purification , Polyomavirus/genetics , Papillomaviridae/genetics , Papillomaviridae/isolation & purification , Case-Control Studies , Coinfection/virology , Coinfection/epidemiology , Aged , Adult , Tumor Virus Infections/virology , Tumor Virus Infections/epidemiology , Tumor Virus Infections/complications , Genotype
2.
Cureus ; 15(9): e45358, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37849579

ABSTRACT

Endomyocardial fibrosis (EMF) is a rare restrictive cardiomyopathy in non-tropical areas. It is seen in most of the patients living in or coming from tropical areas, and is rarely seen in patients who have never visited these areas. It is characterized by fibrotic thickening of the endocardium, predominantly affecting the ventricular apices and inflow tracts. Although thrombus formation is a known complication in various cardiac conditions such as atrial fibrillation, atrial flutter, ventricular heart disease, and patent foramen ovale, the occurrence of bilateral thrombus in EMF is exceptionally rare. We present a case report describing a unique finding of bilateral ventricular thrombus in a patient diagnosed with EMF, highlighting the clinical presentation, diagnostic approach, and management challenges associated with this rare phenomenon.

3.
Med Oncol ; 40(5): 142, 2023 Apr 11.
Article in English | MEDLINE | ID: mdl-37039909

ABSTRACT

Tumor-associated macrophages (TAMs) are an important component of the tumor microenvironment (TME) and have been linked to immunosuppression and poor prognosis. TAMs have been shown to be harmful in ovarian cancer (OC), with a positive correlation between their high levels of tumors and poor overall patient survival. These cells are crucial in the progression and chemoresistance of OC. The primary pro-tumoral role of TAMs is the release of cytokines, chemokines, enzymes, and exosomes that directly enhance the invasion potential and chemoresistance of OC by activating their pro-survival signalling pathways. TAMs play a crucial role in the metastasis of OC in the peritoneum and ascities by assisting in spheroid formation and cancer cell adhesion to the metastatic regions. Furthermore, TAMs interact with tumor protein p53 (TP53), exosomes, and other immune cells, such as stem cells and cancer-associated fibroblasts (CAFs) to support the progression and metastasis of OC. In this review we revisit development, functions and interactions of TAMs in the TME of OC patients to highlight and shed light on challenges and excitement down the road.


Subject(s)
Cancer-Associated Fibroblasts , Ovarian Neoplasms , Humans , Female , Ovarian Neoplasms/metabolism , Macrophages , Signal Transduction , Cytokines/metabolism , Cancer-Associated Fibroblasts/metabolism , Tumor Microenvironment
5.
Nanoscale Res Lett ; 17(1): 72, 2022 Aug 05.
Article in English | MEDLINE | ID: mdl-35930196

ABSTRACT

In this work, the preparation of a PEG@ multi-walled carbon nanotubes (MWCNTs) composite has shown a great potential effect in tumor therapy using graphite powder at room temperature. PEGylated MWCNTs were created and used as a carrier for targeting the antineoplastic drug Ixazomib to myeloma cancer cells (abnormal plasma cells). Ixazomib (MLN2238) was covalently encapsulated into functionalized carbon nanotubes modified with polyethylene glycol (PEG 600) to obtain MWCNTs-PEG-MLN2238. The Ixazomib@ MWCNTs-PEG composite shows promising results as an effective nanocarrier and using a small amount of MWCNTs-PEG-Ixazomib that has a low toxicity compared with that of Ixazomib alone. A multifunctional MWCNTs-PEG-Ixazomib composite is used to test biological effects on multiple myeloma cell lines RPMI 8226 using the MTT assay to enhance treatment efficiency. The cytotoxicity of free Ixazomib citrate (69% cell viability of RPMI8226 cells) was higher than that of MWCNTs-PEG-Ixazomib (91% cell viability) at the same maximum concentration of Ixazomib citrate (50 µg/ml). In this work, we performed a study of preparation of MWCNTs with an acceptable Ixazomib loading efficiency and determination of the drug systemic toxicity for the first time. In this study, the preparation of MWCNTs with acceptable Ixazomib loading efficiency and determination of the drug systemic toxicity was performed for the first time. The MTT assay results show decreasing the toxicity of Ixazomib after loading with the MWCNTs-PEG composite. The MWCNTs-PEG @ Ixazomib show promising results as an effective carrier of Ixazomib and lead to a decrease in the cost of using Ixazomib.

6.
Clin Case Rep ; 10(7): e6080, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35865765

ABSTRACT

In patients with uveal melanoma, cardiac metastases can present without any symptoms. It is becoming more common than previously thought and highlights the importance of routine surveillance after definitive treatment.

7.
Phys Chem Chem Phys ; 24(20): 12601-12620, 2022 May 25.
Article in English | MEDLINE | ID: mdl-35579396

ABSTRACT

The presence of two functional groups (OH and double bond) in C5 methyl-substituted enols (i.e., isopentenols), such as 3-methyl-2-buten-1-ol (prenol) and 3-methyl-3-buten-1-ol (isoprenol), makes them excellent biofuel candidates as fuel additives. As OH radicals are abundant in both combustion and atmospheric environments, OH-initiated oxidation of these isopentenols over wide ranges of temperatures and pressures needs to be investigated. In alkenes, OH addition to the double bond is prominent at low temperatures (i.e., below ∼700 K), and H-atom abstraction dominates at higher temperatures. However, we find that the OH-initiated oxidation of prenol and isoprenol displays a larger role for OH addition at higher temperatures. In this work, the reaction kinetics of prenol and isoprenol with OH radicals was investigated over the temperature range of 900-1290 K and pressure of 1-5 atm by utilizing a shock tube and OH laser diagnostic. To rationalize these chemical systems, variational transition state theory calculations with multi-structural torsional anharmonicity and small curvature tunneling corrections were run using a potential energy surface characterized at the UCCSD(T)/jun-cc-pVQZ//M06-2X/6-311++G(2df,2pd) level of theory. A good agreement was observed between the experiment and theory, with both predicting a non-Arrhenius behavior and negligible pressure effects. OH additions to the double bond of prenol and isoprenol were found to be important, with at least 50% contribution to the total rate constants even at temperatures as high as 700 and 2000 K, respectively. This behavior was attributed to the stabilizing effect induced by hydrogen bonding between the reacting OH radical and the OH functional group of isopentenols at the saddle points. These stabilizing intermolecular interactions help mitigate the entropic effects that hinder association reactions as temperature increases, thus extending the prominent role of addition pathways to high temperatures. The site-specific rate constants were also found to be slower than their analogous reactions of OH + n-alkenes.

8.
Ann Parasitol ; 67(2): 195-202, 2021.
Article in English | MEDLINE | ID: mdl-34592086

ABSTRACT

Trichinellosis is a common parasitic zoonosis. Complications of anthelmintic drugs combined with steroids raise the urge of alternative protective ways. The study aimed to investigate the protective effects of Lactobacillus acidophilus probiotic on both Trichinella spiralis adults and larvae in experimental animal models. Thirty-six male BALB/c mice were divided into 3 groups: negative control Group (G I); Group (G II) mice were inoculated orally by 500 Trichinella spiralis larvae; tested Group (G III) mice were prophylactic by an oral dose of Lactobacillus acidophilus in commercially available form for seven consecutive days, before infection. Mature worms and encysted larvae were counted on the 5th and 21st day post-infection (dpi), respectively. IL-1, IL-6, IL-10 and TNF-α concentrations were estimated at 5th and 21st dpi of all groups. Significant reductions in mean worms and larvae burden were detected by 62.1% and 73.5% in the prophylactic group compared to the non-prophylactic group. The cytokine profiles were revealed IL-1 and IL-6 up-regulation compared to IL-10 and TNF-α down-regulation in the tested group compared to other groups. Although Lactobacillus acidophilus failed to achieve complete eradication of Trichinella spiralis adults and larvae, it showed powerful effects in reducing parasites and cytokines burdens.


Subject(s)
Probiotics , Trichinella spiralis , Trichinellosis , Animals , Feasibility Studies , Lactobacillus acidophilus , Male , Mice , Mice, Inbred BALB C , Trichinellosis/prevention & control
9.
SAGE Open Med Case Rep ; 9: 2050313X211030014, 2021.
Article in English | MEDLINE | ID: mdl-34290869

ABSTRACT

Right aortic arch with a left innominate (brachiocephalic) artery with mirror image branching (RAMI) is a rare congenital anomaly, and it is unusual to diagnose it in adulthood. There are very few cases of cardiac surgery being performed for acquired cardiac disease on a congenital RAMI patient. We present a patient who had an incidental finding of a RAMI anomaly found during coronary artery bypass surgery. Post-operatively computerised tomography showed both his congenital lesions and his bypass grafts.

10.
Clin Case Rep ; 9(5): e04137, 2021 May.
Article in English | MEDLINE | ID: mdl-34026171

ABSTRACT

The probability of right heart thrombus co-existence should be considered in patients with antiphospholipid syndrome (APS) who have pulmonary and cardiac symptoms. The prevention and management of intracardiac thrombotic events include early use of anticoagulation therapy.

11.
Acta Chim Slov ; 67(2): 396-402, 2020 Jun.
Article in English | MEDLINE | ID: mdl-33855568

ABSTRACT

This work describes how to utilize the electrochemical technique to determine labetalol hydrochloride (Lab) in pure form and combined pharmaceutical formulation for quality control purposes. Four membrane sensors were developed using two plasticizers, dioctyl phthalate with 2-hydroxypropyl-?-cyclodextrin and ammonium reineckate (RNC) for sensors 1a and 2a, and tributyl phthalate with 2-hydroxypropyl-?-cyclodextrin and ammonium reineckate for sensors 1b and 2b as ionophores in polyvinyl chloride (PVC) matrix. Fast response and stable Nernstian slopes of 59.60, 57.58, 53.00 and 55.00 mV/decade for sensors 1a, 2a, 1b, and 2b, respectively, were obtained by developed sensors within a concentration range 10-4 M-10-2 M over pH range 2.00-5.10. Developed sensors showed good selectivity for Lab in pure form, in the presence of co-administered drugs, many of interfering ions, and excipients present in pharmaceutical formulation. No remarkable difference was detected upon the statistical comparison between the results of proposed sensors and the official method.


Subject(s)
Labetalol/blood , 2-Hydroxypropyl-beta-cyclodextrin/chemistry , Adrenergic alpha-Antagonists/blood , Adrenergic beta-Antagonists/blood , Diethylhexyl Phthalate/chemistry , Electrochemical Techniques/instrumentation , Electrochemical Techniques/methods , Electrodes , Humans , Hydrogen-Ion Concentration , Ionophores/chemistry , Membranes, Artificial , Phthalic Acids/chemistry , Plasticizers/chemistry , Polyvinyl Chloride/chemistry , Tablets/analysis , Temperature , Thiocyanates/chemistry
12.
Luminescence ; 34(1): 70-76, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30430753

ABSTRACT

Bambuterol (BAM) and terbultaline (TER) are well known and effective bronchodilators. In this article highly sensitive, green and cost-effective spectrofluorimetric methods are designed to determine low concentrations of such drugs. The proposed methods are based on an investigation of the native fluorescence properties of aqueous solutions of BAM at 298 nm after excitation at 263 nm and of TER at 313 nm after excitation at 275 nm. Under optimum conditions, the plots of the relative fluorescence intensity versus concentration were rectilinear over the range 0.1-1.2 µg/mL for BAM and 0.05-0.5 µg/mL for TER with a limit of quantitation of 0.067 µg/mL for BAM and 0.018 µg/mL for TER. The methods are simple and hence suitable for application to the quantification of BAM and TER in syrups and tablets without interference from common excipients. Furthermore, based on United States Pharmacopeia (USP) guidelines, the application was extended to determine the content uniformity of the cited drugs in low dose tablets. The developed methods were fully validated according to the guidelines of the International Conference on Harmonization (ICH).


Subject(s)
Spectrometry, Fluorescence/methods , Terbutaline/analogs & derivatives , Terbutaline/analysis , Calibration , Green Chemistry Technology , Hydrogen-Ion Concentration , Limit of Detection , Reproducibility of Results , Sensitivity and Specificity , Solvents/chemistry , Tablets/analysis
13.
Asian Pac J Cancer Prev ; 19(8): 2291-2297, 2018 Aug 24.
Article in English | MEDLINE | ID: mdl-30139240

ABSTRACT

Background: Endometrial carcinomas are common gynecologic malignancies worldwide. In Egypt they represent 2.6 %. We evaluated the role of morphometry and MMP-9 immunohistochemical expression to differentiate atypical endometrial hyperplasia from low grade endometrial adenocarcinoma. Methods: 60 cases of endometrial lesions that included 25 cases of complex endometrial hyperplasia with atypia, 25 cases of low grade endometrioid adenocarcinoma, in addition to 10 cases of proliferative endometrium as a control group. Morphometric measurements and D-score were evaluated. MMP9 was performed using streptavidin ­biotin immunoperoxidase system. Results: D score was more than 1 in 100% of cases of proliferative endometrium. In atypical hyperplasia 28 % of cases had a D-score more than 1, 44% less than 0 and 28% of cases had a D score between 0 and 1 with uncertain prognosis. All carcinoma cases had D-score less than 0. MMP9 was positive in all cases of the study but differ in its degree of expression; proliferative endometrium with low expression. Atypical hyperplasia divided as 52% low expression and 48% high expression. Most of the Endometrial adenocarcinoma cases (92%) showed high expression. There was significant difference in expression of MMP9 in atypical endometrial hyperplasia and endometrial adenocarcinoma (p> 0.001). Conclusion: The relation between MMP9 expression and D-score value in cases of atypical endometrial hyperplasia was highly significant P>0.001Thus, incorporating both MMP9 immunoexpression and D-score value would increase the accuracy of diagnosis of atypical endometrial hyperplasia and low grade endometrial adenocarcinoma.


Subject(s)
Biomarkers, Tumor/metabolism , Carcinoma, Endometrioid/pathology , Endometrial Hyperplasia/pathology , Endometrium/pathology , Image Processing, Computer-Assisted/methods , Matrix Metalloproteinase 9/metabolism , Precancerous Conditions/pathology , Adult , Carcinoma, Endometrioid/metabolism , Case-Control Studies , Endometrial Hyperplasia/metabolism , Endometrium/metabolism , Female , Follow-Up Studies , Humans , Middle Aged , Precancerous Conditions/metabolism , Prognosis , Retrospective Studies
14.
J Phys Chem A ; 122(30): 6277-6291, 2018 Aug 02.
Article in English | MEDLINE | ID: mdl-29983052

ABSTRACT

Hydroperoxyalkylperoxy (OOQOOH) radicals are important intermediates in combustion chemistry. The conventional isomerization of OOQOOH radicals to form ketohydroperoxides has been long believed to be the most important chain branching reaction under the low-temperature combustion conditions. In this work, the kinetics of competing pathways (alternative isomerization, concerted elimination, and H-exchange pathways) to the conventional isomerization of different ß-, γ- and Δ-OOQOOH butane isomers are investigated. Six- and seven-membered ring conventional isomerizations are found to be the dominant pathways, whereas alternative isomerizations are more important than conventional isomerization, when the latter proceeded via a more strained transition state ring. The oxygen atoms in OOQOOH radicals introduce intramolecular hydrogen bonding (HB) that significantly affects the energies of reacting species and transition states, ultimately influencing chemical kinetics. Conceptually, HB has a dual effect on the stability of chemical species, the first being the stabilizing effect of the actual intramolecular HB force, and the second being the destabilizing effect of ring strain imposed by the HB conformer. The overall effect can be quantified by determining the difference between the minimum energy conformers of a chemical species or transition state that have HB and that do not have HB (non-hydrogen bonding (NHB)). The stabilization effect of HB on the species and transition sates is assessed, and its effect on the calculated rate constants is also considered. Our results show that, for most species and transition states, HB stabilizes their energies by as much as 2.5 kcal/mol. However, NHB conformers are found to be more stable by up to 2.7 kcal/mol for a few of the considered species. To study the effect of HB on rate constants, reactions are categorized into two groups ( groups one and two) based on the structural similarity of the minimum energy conformers of the reactant and transition state, for a particular reaction. For cases where the reactant and transition state conformers are similar (i.e., both HB or NHB structures), group one, the effect of HB on reaction kinetics is major only if the magnitudes of the stabilization energy of the reactant and transition state are quite different. Meanwhile, for group two, where the reactant and transition state prefer different conformers (one HB and the other NHB), HB affects the kinetics when the stabilization energy of the reactant or transition state is significant or the entropy effect is important. This information is useful in determining corrections accounting for HB effects when assigning rate parameters for chemical reactions using estimation and/or analogy, where analogies usually result in inaccuracies when modeling atmospheric and combustion processes.

15.
Int J Biol Macromol ; 113: 1105-1115, 2018 Jul 01.
Article in English | MEDLINE | ID: mdl-29545064

ABSTRACT

Despite the potential antimicrobial and water purification benefits of chitosan-based nanocomposites, there are growing concerns regarding the hazards of leached nanoparticles (NPs) to the in-contact circumference. The antibacterial performance of the nanocomposites of chitosan with silver and copper NPs and carbon nanotubes was assessed with an emphasis on their impact on fish health. The minimal inhibitory concentrations of each preparation and the growth curves of Aeromonas hydrophila exposed to different nanocomposites were measured. Five groups of Oreochromis niloticus were exposed to chitosan nanocomposites for three weeks. A combination of a low concentration of the NPs in the chitosan matrix improved their antimicrobial properties. However, aqueous exposure to these materials still had hazardous effects on fish health. Experimental groups of O. niloticus exposed to these nanocomposites exhibited oxidative stress, tissue DNA fragmentation and higher expression of pro-inflammatory and immune-related genes such as TNF-α and IL1ß. Various pathological tissue alterations were observed in gills, liver, spleen and intestine. Exposure to some of the prepared nanocomposites led to significant DNA damage in hepatic cells with a marked increase in the apoptotic index.


Subject(s)
Anti-Infective Agents/chemistry , Aquatic Organisms/drug effects , Chitosan/chemistry , Copper/chemistry , Nanocomposites/chemistry , Nanotubes, Carbon/chemistry , Silver/chemistry , Aeromonas hydrophila/drug effects , Aeromonas hydrophila/growth & development , Animals , Anti-Infective Agents/pharmacology , Anti-Infective Agents/toxicity , Cichlids/metabolism , Cytokines/metabolism , Dose-Response Relationship, Drug , Ecotoxicology , Gene Expression Regulation/drug effects , Microbial Sensitivity Tests , Oxidative Stress/drug effects , Risk Assessment
16.
J Phys Chem A ; 122(14): 3626-3639, 2018 Apr 12.
Article in English | MEDLINE | ID: mdl-29518339

ABSTRACT

Hydroperoxyalkylperoxy (OOQOOH) radical isomerization is an important low-temperature chain branching reaction within the mechanism of hydrocarbon oxidation. This isomerization may proceed via the migration of the α-hydrogen to the hydroperoxide group. In this work, a combination of high level composite methods-CBS-QB3, G3, and G4-is used to determine the high-pressure-limit rate parameters for the title reaction. Rate rules for H-migration reactions proceeding through 5-, 6-, 7-, and 8-membered ring transitions states are determined. Migrations from primary, secondary and tertiary carbon sites to the peroxy group are considered. Chirality is also investigated by considering two diastereomers for reactants and transition states with two chiral centers. This is important since chirality may influence the energy barrier of the reaction as well as the rotational energy barriers of hindered rotors in chemical species and transition states. The effect of chirality and hydrogen bonding interactions in the investigated energies and rate constants is studied. The results show that while the energy difference between two diastereomers ranges from 0.1-3.2 kcal/mol, chirality hardly affects the kinetics, except at low temperatures (atmospheric conditions) or when two chiral centers are present in the reactant. Regarding the effect of the H-migration ring size, it is found that in most cases, the 1,5 and 1,6 H-migration reactions have similar rates at low temperatures (below ∼830 K) since the 1,6 H-migration proceeds via a cyclohexane-like transition state similar to that of the 1,5 H-migration.

17.
Biologicals ; 51: 46-53, 2018 Jan.
Article in English | MEDLINE | ID: mdl-29126666

ABSTRACT

Efficacy maximization of inactivated avian influenza vaccine using safe adjuvants was investigated. Chitosan nanoparticles were prepared by ionic gelation method with average size of 150 nm and their Zeta potential was 11.5 mV. After encapsulation of avian influenza vaccine, the average size was 397 nm and Zeta potential was 4.29 mV. The highest HI antibody titer results were shown in chicken group vaccinated with inactivated avian influenza virus AIV-chitosan followed by the group vaccinated with inactivated AIV-chitosan nanoparticles then the group vaccinated with oil inactivated AIV vaccine, on using chicken antigen at 2 weeks post second vaccination. Upon using duck antigen, the highest HI antibody titers were shown in chicken group vaccinated with inactivated AIV oil emulsion vaccine followed by chicken group vaccinated with AIV-chitosan nanoparticles then the group vaccinated with AIV-chitosan. Chicken in the group vaccinated with AIV-chitosan nanoparticles induced the best results of lymphocyte proliferation assay. The results of phagocytic activity percentage and phagocytic index of AIV-chitosan nanoparticles and AIV-chitosan groups at 3 days post first vaccination were increased significantly in comparison with other groups, whereas at 14 days post first vaccination, group vaccinated with AIV-chitosan nanoparticles showed significant increase in phagocytic activity percentage and phagocytic index.


Subject(s)
Chitosan/chemistry , Influenza A virus/immunology , Influenza Vaccines/immunology , Nanoparticles/chemistry , Vaccines, Inactivated/immunology , Animals , Antibodies, Viral/immunology , Chick Embryo , Chickens , Drug Compounding , Ducks , Influenza in Birds/immunology , Influenza in Birds/virology , Nanoparticles/ultrastructure , Vaccination
18.
Proc Natl Acad Sci U S A ; 114(50): 13102-13107, 2017 12 12.
Article in English | MEDLINE | ID: mdl-29183984

ABSTRACT

Decades of research on the autooxidation of organic compounds have provided fundamental and practical insights into these processes; however, the structure of many key autooxidation intermediates and the reactions leading to their formation still remain unclear. This work provides additional experimental evidence that highly oxygenated intermediates with one or more hydroperoxy groups are prevalent in the autooxidation of various oxygenated (e.g., alcohol, aldehyde, keto compounds, ether, and ester) and nonoxygenated (e.g., normal alkane, branched alkane, and cycloalkane) organic compounds. These findings improve our understanding of autooxidation reaction mechanisms that are routinely used to predict fuel ignition and oxidative stability of liquid hydrocarbons, while also providing insights relevant to the formation mechanisms of tropospheric aerosol building blocks. The direct observation of highly oxygenated intermediates for the autooxidation of alkanes at 500-600 K builds upon prior observations made in atmospheric conditions for the autooxidation of terpenes and other unsaturated hydrocarbons; it shows that highly oxygenated intermediates are stable at conditions above room temperature. These results further reveal that highly oxygenated intermediates are not only accessible by chemical activation but also by thermal activation. Theoretical calculations on H-atom migration reactions are presented to rationalize the relationship between the organic compound's molecular structure (n-alkane, branched alkane, and cycloalkane) and its propensity to produce highly oxygenated intermediates via extensive autooxidation of hydroperoxyalkylperoxy radicals. Finally, detailed chemical kinetic simulations demonstrate the influence of these additional reaction pathways on the ignition of practical fuels.

19.
Biomed Pharmacother ; 88: 52-60, 2017 Apr.
Article in English | MEDLINE | ID: mdl-28092845

ABSTRACT

Cinnamon has a history of use for medicinal purposes and its major benefits have been linked to cinnamaldehyde. The present study aimed to investigate the hypoglycemic action of cinnamaldehyde against fatty-sucrosed diet/streptozotocin (FSD/STZ)-rat model of gestational diabetes. Female albino rats were divided into three groups. Group I fed with normal diet (ND) while group II and III were fed with FSD for eight weeks (five weeks pre-gestational and three weeks gestational). Rats of group III were administered with a daily oral dose of 20mg/kg cinnamaldehyde one week before mating onward. At the 7th day of gestation, FSD-fed rats were injected intraperitoneally with STZ (25mg/kg b.wt.) to induce gestational diabetes. Pre-mating treatment of cinnamaldehyde controls hyperphagia and glucose intolerance during the gestational period than in diabetic rats. It also reduced levels of fructosamine, total cholesterols, triglycerides, leptin, tumor necrosis factor-alpha (TNF-α), malondialdehyde (MDA) and nitric oxide (NO), while it significantly increased levels of high-density lipoprotein (HDL)-cholesterol, adiponectin, liver glycogen, reduced glutathione (GSH) and catalase activity at term pregnancy. In addition, cinnamaldehyde administration up-regulated the mRNA expression of peroxisome proliferated activated receptor-gamma (PPARγ) and also ameliorated the number of viable fetuses, implantation loss sites, fetal glucose and insulin levels. In conclusion, cinnamaldehyde has safe hypoglycemic action on gestational diabetes by potentiating insulin secretion and sensitivity through activating the antioxidant defense system, suppressing pro-inflammatory cytokines production, upregulating PPARγ gene expression and alleviating the reproductive performance.


Subject(s)
Acrolein/analogs & derivatives , Cytokines/metabolism , Diabetes, Gestational/drug therapy , Diabetes, Gestational/pathology , Hyperglycemia/drug therapy , Inflammation Mediators/metabolism , Oxidative Stress , PPAR gamma/metabolism , Acrolein/pharmacology , Acrolein/therapeutic use , Adipose Tissue/metabolism , Animals , Antioxidants/metabolism , Biomarkers/metabolism , Blood Glucose/metabolism , Body Weight/drug effects , Cholesterol/blood , Diabetes, Gestational/blood , Diabetes, Gestational/genetics , Feeding Behavior/drug effects , Female , Fetus/metabolism , Fructosamine/blood , Glucose Tolerance Test , Glycogen/metabolism , Hyperglycemia/blood , Hyperglycemia/genetics , Hyperglycemia/pathology , Insulin/blood , Leptin/blood , Liver/metabolism , Oxidative Stress/drug effects , PPAR gamma/genetics , Pregnancy , Pregnancy Outcome , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Triglycerides/blood
20.
J Phys Chem A ; 120(14): 2201-17, 2016 Apr 14.
Article in English | MEDLINE | ID: mdl-26998618

ABSTRACT

Accurate chemical kinetic combustion models of lightly branched alkanes (e.g., 2-methylalkanes) are important to investigate the combustion behavior of real fuels. Improving the fidelity of existing kinetic models is a necessity, as new experiments and advanced theories show inaccuracies in certain portions of the models. This study focuses on updating thermodynamic data and the kinetic reaction mechanism for a gasoline surrogate component, 2-methylhexane, based on recently published thermodynamic group values and rate rules derived from quantum calculations and experiments. Alternative pathways for the isomerization of peroxy-alkylhydroperoxide (OOQOOH) radicals are also investigated. The effects of these updates are compared against new high-pressure shock tube and rapid compression machine ignition delay measurements. It is shown that rate constant modifications are required to improve agreement between kinetic modeling simulations and experimental data. We further demonstrate the ability to optimize the kinetic model using both manual and automated techniques for rate parameter tunings to improve agreement with the measured ignition delay time data. Finally, additional low temperature chain branching reaction pathways are shown to improve the model's performance. The present approach to model development provides better performance across extended operating conditions while also strengthening the fundamental basis of the model.

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