41 research outputs found

    Experimental Study to Investigate the Effect of Polyacrylamide Gel to Reduce the Lost Circulation

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    One of the challenging issues encountered during drilling operations is the lost circulation. Numerous issues might arise because of losses, such as wasting of time and higher drilling cost. Several types of lost circulation materials have been developed and are being used to limit mud losses and avoid associated issues. Each solution has benefits and drawbacks. In this study, a core flooding test was performed to study the effectiveness of polyacrylamide (PAM) granular gel on the reduction of the circulation lost. One common type of fracture characteristic is fractures with tips, commonly known as partially open fracture (POF). However, PAM gel therapy in POFs received little attention in prior research. Models of partly open fractures were built using a cylindrical core. A series of processes are performed on a core to get a POF model. Overall, the PAM gel can decrease plug permeability, making it a useful material for lost circulation. The results indicate that the Polyacrylamide granular gel can decrease the permeability up to 193 times

    A descriptive analysis of child-relevant systematic reviews in the Cochrane Database of Systematic Reviews

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    <p>Abstract</p> <p>Background</p> <p>Systematic reviews (SRs) are considered an important tool for decision-making. There has been no recent comprehensive identification or description of child-relevant SRs. A description of existing child-relevant SRs would help to identify the extent of available child-relevant evidence available in SRs and gaps in the evidence base where SRs are required. The objective of this study was to describe child-relevant SRs from the Cochrane Database of Systematic Reviews (CDSR, Issue 2, 2009).</p> <p>Methods</p> <p>SRs were assessed for relevance using pre-defined criteria. Data were extracted and entered into an electronic form. Univariate analyses were performed to describe the SRs overall and by topic area.</p> <p>Results</p> <p>The search yielded 1666 SRs; 793 met the inclusion criteria. 38% of SRs were last assessed as up-to-date prior to 2007. Corresponding authors were most often from the UK (41%). Most SRs (59%) examined pharmacological interventions. 53% had at least one external source of funding. SRs included a median of 7 studies (IQR 3, 15) and 679 participants (IQR 179, 2833). Of all studies, 48% included only children, and 27% only adults. 94% of studies were published in peer-reviewed journals. Primary outcomes were specified in 72% of SRs. Allocation concealment and the Jadad scale were used in 97% and 25% of SRs, respectively. Adults and children were analyzed separately in 12% of SRs and as a subgroup analysis in 14%. Publication bias was assessed in only 14% of SRs. A meta-analysis was conducted in 68% of SRs with a median of 5 trials (IQR 3, 9) each. Variations in these characteristics were observed across topic areas.</p> <p>Conclusions</p> <p>We described the methodological characteristics and rigour of child-relevant reviews in the CDSR. Many SRs are not up-to-date according to Cochrane criteria. Our study describes variation in conduct and reporting across SRs and reveals clinicians' ability to access child-specific data.</p

    Novel Evolved Immunoglobulin (Ig)-Binding Molecules Enhance the Detection of IgM against Hepatitis C Virus

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    Detection of specific antibodies against hepatitis C virus (HCV) is the most widely available test for viral diagnosis and monitoring of HCV infections. However, narrowing the serologic window of anti-HCV detection by enhancing anti-HCV IgM detection has remained to be a problem. Herein, we used LD5, a novel evolved immunoglobulin-binding molecule (NEIBM) with a high affinity for IgM, to develop a new anti-HCV enzyme-linked immunosorbent assay (ELISA) using horseradish peroxidase-labeled LD5 (HRP-LD5) as the conjugated enzyme complex. The HRP-LD5 assay showed detection efficacy that is comparable with two kinds of domestic diagnostic kits and the Abbott 3.0 kit when tested against the national reference panel. Moreover, the HRP-LD5 assay showed a higher detection rate (55.9%, 95% confidence intervals (95% CI) 0.489, 0.629) than that of a domestic diagnostic ELISA kit (Chang Zheng) (53.3%, 95% CI 0.463, 0.603) in 195 hemodialysis patient serum samples. Five serum samples that were positive using the HRP-LD5 assay and negative with the conventional anti-HCV diagnostic ELISA kits were all positive for HCV RNA, and 4 of them had detectable antibodies when tested with the established anti-HCV IgM assay. An IgM confirmation study revealed the IgM reaction nature of these five serum samples. These results demonstrate that HRP-LD5 improved anti-HCV detection by enhancing the detection of anti-HCV IgM, which may have potential value for the early diagnosis and screening of hepatitis C and other infectious diseases

    Use of anticoagulants and antiplatelet agents in stable outpatients with coronary artery disease and atrial fibrillation. International CLARIFY registry

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    Elevated Levels of Interleukin-8 in Serum Are Associated with Hepatitis C Virus Infection and Resistance to Interferon Therapy

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    Hepatitis C virus (HCV), a major cause of liver disease worldwide, is frequently resistant to the antiviral alpha interferon (IFN). We have recently found that the HCV NS5A protein induces expression of the proinflammatory chemokine IL-8 to partially inhibit the antiviral actions of IFN in vitro. To extend these observations, in the present study we examined the relationship between levels of IL-8 in serum, HCV infection, and biochemical response to IFN therapy. Levels of IL-8 were significantly elevated in 132 HCV-infected patients compared to levels in 32 normal healthy subjects and were also significantly higher in patients who did not respond to IFN therapy than in patients who did respond to therapy. This study suggests that HCV-induced changes in levels of chemokine and cytokine expression may be involved in HCV antiviral resistance, persistence, and pathogenesis

    Design, synthesis, in silico and in vitro antimicrobial screenings of novel 1,2,4-triazoles carrying 1,2,3-triazole scaffold with lipophilic side chain tether

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    Abstract Background 1,2,4-Triazoles and 1,2,3-triazoles have gained significant importance in medicinal chemistry. Results This study describes a green, efficient and quick solvent free click synthesis of new 1,2,3-triazole-4,5-diesters carrying a lipophilic side chain via 1,3-dipolar cycloaddition of diethylacetylene dicarboxylate with different surfactant azides. Further structural modifications of the resulting 1,2,3-triazole diesters to their corresponding 1,2,4-triazole-3-thiones via multi-step synthesis has been also investigated. The structures of the newly designed triazoles have been elucidated based on their analytical and spectral data. These compounds were evaluated for their antimicrobial activities. Relative to the standard antimicrobial agents, derivatives of 1,2,3-triazole-bis-4-amino-1,2,4-triazole-3-thiones were the most potent antimicrobial agents with compound 7d demonstrating comparable antibacterial and antifungal activities against all tested microorganisms. Further, the selected compounds were studied for docking using the enzyme, Glucosamine-6-phosphate synthase. Conclusions The in silico study reveals that all the synthesized compounds had shown good binding energy toward the target protein ranging from − 10.49 to − 5.72 kJ mol−1 and have good affinity toward the active pocket, thus, they may be considered as good inhibitors of GlcN-6-P synthase

    Design, synthesis, ADME prediction and pharmacological evaluation of novel benzimidazole-1,2,3-triazole-sulfonamide hybrids as antimicrobial and antiproliferative agents

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    Abstract Background Nitrogen heterocyclic rings and sulfonamides have attracted attention of several researchers. Results A series of regioselective imidazole-based mono- and bis-1,4-disubstituted-1,2,3-triazole-sulfonamide conjugates 4a–f and 6a–f were designed and synthesized. The first step in the synthesis was a regioselective propargylation in the presence of the appropriate basic catalyst (Et3N and/or K2CO3) to afford the corresponding mono-2 and bis-propargylated imidazoles 5. Second, the ligation of the terminal C≡C bond of mono-2 and/or bis alkynes 5 to the azide building blocks of sulfa drugs 3a–f using optimized conditions for a Huisgen copper (I)-catalysed 1,3-dipolar cycloaddition reaction yielded targeted 1,2,3-triazole hybrids 4a–f and 6a–f. The newly synthesized compounds were screened for their in vitro antimicrobial and antiproliferative activities. Among the synthesized compounds, compound 6a emerged as the most potent antimicrobial agent with MIC values ranging between 32 and 64 µg/mL. All synthesized molecules were evaluated against three aggressive human cancer cell lines, PC-3, HepG2, and HEK293, and revealed sufficient antiproliferative activities with IC50 values in the micromolar range (55–106 μM). Furthermore, we conducted a receptor-based electrostatic analysis of their electronic, steric and hydrophobic properties, and the results were in good agreement with the experimental results. In silico  ADMET prediction studies also supported the experimental biological results and indicated that all compounds are nonmutagenic and noncarcinogenic. Conclusion In summary, we have successfully synthesized novel targeted benzimidazole-1,2,3-triazole-sulfonamide hybrids through 1,3-dipolar cycloaddition reactions between the mono- or bis-alkynes based on imidazole and the appropriate sulfonamide azide under the optimized Cu(I) click conditions. The structures of newly synthesized sulfonamide hybrids were confirmed by means of spectroscopic analysis. All newly synthesized compounds were evaluated for their antimicrobial and antiproliferative activities. Our results showed that the benzimidazole-1,2,3-triazole-sulfonamide hybrids inhibited microbial and fungal strains within MIC values from 32 to 64 μg/mL. The antiproliferative evaluation of the synthesized compounds showed sufficient antiproliferative activities with IC50 values in the micromolar range (55–106 μM). In conclusion, compound 6a has remarkable antimicrobial activity. Pharmacophore elucidation of the compounds was performed based on in silico ADMET evaluation of the tested compounds. Screening results of drug-likeness rules showed that all compounds follow the accepted rules, meet the criteria of drug-likeness and follow Lipinski’s rule of five. In addition, the toxicity results showed that all compounds are nonmutagenic and noncarcinogenic
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