37 research outputs found

    Evaluasi Terjepitnya Rangkaian Pipa Pemboran pada Sumur “Jh-151” Lapangan X di PT. Pertamina Ep

    Full text link
    Operasi pemboran yang dilakukan tidak selalu berjalan dengan lancar, adakalanya timbul masalah yang dapatmenghambat jalannya operasi pemboran tersebut. Masalah-masalah yang berhubungan dengan pemboransumur minyak sebagian besar disebabkan oleh karena gangguan terhadap tegangan tanah (earth stress) disekitar lubang bor yang disebabkan oleh pembuatan lubang itu sendiri dan adanya interaksi antara lumpurpemboran dengan formasi yang ditembus. Tegangan tanah bersama tekanan formasi berusaha untukmengembalikan keseimbangan yang telah ada sebelumnya dengan cara mendorong lapisan batuan kearahlubang bor. Lubang bor dijaga agar tetap stabil dengan cara menyeimbangkan tegangan tanah dan tekanan poridi satu sisi dengan tekanan lumpur pemboran di sekitar lubang bor dan komposisi kimia lumpur bor pada sisiyang lain. Setiap kali keseimbangan ini diganggu maka timbullah masalah-masalah di lubang bor. Salah satumasalah itu adalah terjepitnya rangkaian pemboran. Hambatan operasi pemboran pada sumur menyebabkanwaktu operasi menjadi lebih lama dari yang direncanakan, serta meningkatnya biaya pemboran sampai dua kalilipat dari biaya yang dianggarkan. Hambatan pemboran berupa rangkaian terjepit oleh guguran formasi ( HolePack-Off), merupakan hambatan utama yang terjadi pada interval 8 ½”. Metode yang dilakukan dalampenanggulangan stuck pipe pada sumur ini, yaitu dengan back off, dikarenakan dengan metode work on pipe,sirkulasi, dan perendaman, namun pipa tidak dapat terlepas. Pemboran dilanjutkan dengan side track untukmencapai target displacement yang direncanakan

    Neurotensin(8–13) analogs as dual NTS1 and NTS2 receptor ligands with enhanced effects on a mouse model of Parkinson's disease

    Get PDF
    : The modulatory interactions between neurotensin (NT) and the dopaminergic neurotransmitter system in the brain suggest that NT may be associated with the progression of Parkinson's disease (PD). NT exerts its neurophysiological effects by interactions with the human NT receptors type 1 (hNTS1) and 2 (hNTS2). Therefore, both receptor subtypes are promising targets for the development of novel NT-based analogs for the treatment of PD. In this study, we used a virtually guided molecular modeling approach to predict the activity of NT(8-13) analogs by investigating the docking models of ligands designed for binding to the human NTS1 and NTS2 receptors. The importance of the residues at positions 8 and/or 9 for hNTS1 and hNTS2 receptor binding affinity was experimentally confirmed by radioligand binding assays. Further in vitro ADME profiling and in vivo studies revealed that, compared to the parent peptide NT(8-13), compound 10 exhibited improved stability and BBB permeability combined with a significant enhancement of the motor function and memory in a mouse model of PD. The herein reported NTS1/NTS2 dual-specific NT(8-13) analogs represent an attractive tool for the development of therapeutic strategies against PD and potentially other CNS disorders

    Apple polyphenols in human and animal health*

    Get PDF
    Apples contain substantial amounts of polyphenols, and diverse phenolics mainly flavonoids and phenolic acids, have been identified in their flesh and skins. This work aimed to analyze the overall landscape of the research literature published to date on apple phenolic compounds in the context of human and animal health. The Web of Science Core Collection electronic database was queried with (apple* polyphenol*) AND (health* OR illness* OR disease* OR medic* OR pharma*) to identify relevant papers covering these words and their derivatives in the titles, abstracts, and keywords. The resulted 890 papers were bibliometrically analyzed. The VOSviewer software was utilized to produce term maps that illustrate how the frequent phrases fared in terms of publication and citation data. The apple polyphenol papers received global contributions, particularly from China, Italy, the United States, Spain, and Germany. Examples of frequently mentioned chemicals/chemical classes are quercetin, anthocyanin, catechin, epicatechin, and flavonol, while examples of frequently mentioned medical conditions are cardiovascular disease, atherosclerosis, diabetes, Alzheimers disease, and obesity. The potential health benefits of apple polyphenols on humans and animals are diverse and warrant further study.Authors acknowledge the support from The National Centre for Research and Development (NCBR) of Poland (project number POIR.01.01.01-00-0593/18).info:eu-repo/semantics/publishedVersio

    New Myrtenal-Adamantane Conjugates Alleviate Alzheimer's-Type Dementia in Rat Model.

    Get PDF
    Alzheimer's disease (AD) is a neurodegenerative disease associated with memory impairment and other central nervous system (CNS) symptoms. Two myrtenal-adamantane conjugates (MACs) showed excellent CNS potential against Alzheimer's models. Adamantane is a common pharmacophore for drug design, and myrtenal (M) demonstrated neuroprotective effects in our previous studies. The aim of this study is to evaluate the MACs' neuroprotective properties in dementia. METHODS: Scopolamine (Scop) was applied intraperitoneally in Wistar rats for 11 days, simultaneously with MACs or M as a referent, respectively. Brain acetylcholine esterase (AChE) activity, noradrenaline and serotonin levels, and oxidative brain status determination followed behavioral tests on memory abilities. Molecular descriptors and docking analyses for AChE activity center affinity were performed. RESULTS: M derivatives have favorable physicochemical parameters to enter the CNS. Both MACs restored memory damaged by Scop, showing significant AChE-inhibitory activity in the cortex, in contrast to M, supported by the modeling analysis. Moderate antioxidant properties were manifested by glutathione elevation and catalase activity modulation. MACs also altered noradrenaline and serotonin content in the hippocampus. CONCLUSION: For the first time, neuroprotective properties of two MACs in a rat dementia model were observed. They were stronger than the natural M effects, which makes the substances promising candidates for AD treatment

    Vasoactive intestinal peptide protects guinea-pig detrusor nerves from anoxia/glucopenia injury

    No full text
    Vasoactive intestinal peptide (VIP) was tested for its capability to protect the intrinsic nerves of guinea-pig urinary bladder from damage due to anoxia/glucopenia and reperfusion. Guinea-pig detrusor strips were mounted for tension recording in small organ baths and the nerves were subjected to electric field stimulation. VIP (0.3 microM) improved significantly the response of strips to electrical field stimulation either during anoxia/glucopenia or thereafter during reperfusion, as compared to untreated tissues. The antioxidant activity of VIP assessed as its capability to scavenge peroxyl radicals during linoleic acid oxidation corresponded to 6.42+/-0.13 pIC(50) M, i.e. close to the concentration proved to protect strips against the anoxic--glucopenic and reperfusion damage

    Neurotensin modulation of acetylcholine and gaba release from the rat hippocampus: an in vivo microdialysis study

    No full text
    The effects of neurotensin (NT) on the release of acetylcholine (ACh), aspartate (Asp), glutamate (Glu) and γ-aminobutyric acid (GABA) from the hippocampus of freely moving rats were studied by transversal microdialysis. ACh was detected by High Performance Liquid Chromatography (HPLC) with electrochemical detection while GABA, glutamate and aspartate were measured using HPLC with fluorometric detection. Neurotensin (0.2 and 0.5 μM) administered locally through the microdialysis probe to the hippocampus produced a long-lasting and concentration-dependent increase in the basal extracellular levels of GABA and ACh but not of glutamate and aspartate. The increase in the extracellular levels of GABA and ACh produced by 0.5 μM neurotensin in the hippocampus reached a maximum of about 310% for GABA and 250% for ACh. This stimulant effect of NT was antagonized by the NT receptor antagonist SR 48692 (100 μg\kg, i.p.). Local infusion of tetrodotoxin (1 μM) decreased the basal release of ACh, GABA, Asp, Glu and prevented the 0.2 μM NT-induced increase in GABA and ACh release. The effect of NT on the release of ACh was blocked by the GABA A receptor antagonist bicuculline (2–10 μM). Our findings indicate for the first time that neurotensin plays a neuromodulatory role in the regulation of GABAergic and cholinergic neuronal activity in the hippocampus of awake and freely moving rats. The potentiating effects of neurotensin on GABA and ACh release in the hippocampus are probably mediated by (i) NT receptors located on GABAergic cell bodies and (ii) through GABA A receptors located on cholinergic nerve terminals

    Literature Review Artificial Intelligence Deteksi Hasil Ctscan Paru-Paru Pasien Terjangkit COVID-19

    Full text link
    Penyakit Virus Corona 19 (COVID-19) merupakan penyakit menular yang disebabkan oleh virus corona yang baru-baru ini ditemukan. Saat ini COVID-19 menjadi fenomena permasalahan untuk kita semua namun hingga sekarang belum ada obat yang ditemukan ampuh dalam mengatasinya. Persoalan lain adalah pada proses pendeteksian orang terjangkit. Hasil pendeteksian Covid-19 menggunakan PCR Swap masih dianggap sangat lambat dan menggunakan Rapid Tes bahkan dianggap kurang meyakinkan dengan melihat beberapa kasus yang ada sebelumnya. Tujuan penelitian ini untuk pendeteksian orang terjangkit COVID-19 lebih cepat dengan tingkat akurasi yang tinggi menggunakan metode Artificial Intelligence yang lebih khusus menggunakan Deep Learning arsitektur Convolutional Neural Network (CNN). Metode penelitian yang digunakan adalah literature review, dimana artikel dikumpulkan dan diproses menggunakan aplikasi mendeley, kriteria artikel yang digunakan adalah yang diterbitkan tahun 2020 yang berkaitan dengan penanganan COVID-19 khususnya yang memanfaatkan Artificial Intelligence dalam pembahasannya. Dengan mengumpulkan dan membahas beberapa penelitian yang ada maka dapat dikatakan bahwa dengan menggunakan Artificial Intelligence sistem dapat mendeteksi terjangkitnya seseorang melalui analisa pola yang ada pada hasil CT Scan Paru dengan memanfaatkan tingkat akurasi data latih yang ada

    Mechanical response to electrical field stimulation of rat, guinea-pig, monkey and human detrusor muscle: a comparative study.

    No full text
    The aim of the present investigation was to compare mechanical responses to electrical field stimulation (EFS), as well as cholinergic and non-adrenergic, noncholinergic (NANC) neurotransmission in guinea-pig, rat, monkey and human detrusor muscle strips. Responses to EFS (0.05, 0.5 and 1 ms pulse duration, 50 V, 1-15 Hz) of guinea-pig, rat, monkey and human detrusor muscle strips were recorded isometrically before and after blockade of muscarinic receptors and/or P2-purinoreceptors, as well as after desensitisation of P2-purinoceptors or blockade of the nerve impulse propagation. Single pulses of 0.05 ms duration elicited responses, in either guinea-pig or rat detrusor strips, which were abolished by tetrodotoxin (TTX), thus suggesting their neurogenic nature. In monkey and human detrusor strips, however, the same single pulses were not sufficient to generate contractile responses. The response of either rat or guinea-pig strips to single pulses of 0.5 ms and 1 ms duration was mainly myogenic in nature. While in rat and guinea-pig strips the neurogenic response was only partly reduced in the presence of atropine, in monkey and human strips it was abolished. In the presence of atropine, while suramin only partially reduced the EFS response either in rat or guinea-pig detrusor strips, a complete alpha,beta-methyleneATP-sensitive response was evident in guinea-pig detrusor strips. This suggests the involvement of other transmitter(s) beyond ATP in the NANC response of rat detrusor strips

    Metal complexes of ursodeoxycholic acid and its metal complexes as potential antitumor agents against colon cancer

    No full text
    Colorectal cancer (CRC) takes the third place among the most commonly diagnosed cancer in males and the sec­ond in females. It is the second leading cause of death among neoplastic diseases worldwide.The physiological role of bile acids (BAs) is well known. The prevalence and clinical application of ursodeoxycho­lic acid (UDCA) as well as the data on participation of BAs in the pathogenesis of several liver diseases and gas­trointestinal (colon) tumorigenesis provoke interest in the relationship between UDCA and cancer. Experimen­tal evidence (in vitro and animal studies) suggests that ursodeoxycholic acid may have chemopreventive actions in colorectal cancer.The aim of our study was to evaluate the influence of Cu(II), Zn(II) and Ni(II) complexes of ursodeoxycholic ac­ids on viability and proliferation of cultured human colon cancer cells.In our investigations, we used the permanent cell line HT29 (human colorectal carcinoma) as a model system. The compounds tested were applied at concentrations of 10-200 μg/mL for 24-96 h (for short-term experiments with monolayer cell cultures) and 30 days (for long-term experiments with 3D cell colonies) and their effect on cell viability and proliferation was evaluated by the MTT test, neutral red uptake cytotoxicity assay, crystal violet staining, trypan blue dye exclusion technique, double staining with acridine orange and propidium iodide and colony-forming method.Our results showed that the compounds investigated decreased viability and proliferation of the treated cells in a time- and concentration-dependent manner. Metal complexes expressed more pronounced cytotoxic/cytostatic activity compared to the corresponding ligand ursodeoxycholic acid.The metal complexes examined exhibited promising cytotoxic/antiproliferative properties against HT29 colon cancer cells and deserve further studies to clarify better their anti-tumor potential.Acknowledgements: This study was funded by Grant DFNP-17-89/28.07.2017 from the Program `Support of Young Scientists at the Bulgarian Academy of Sciences` and by a mutual project between the Bulgarian Academy of Sciences and the Romanian Academy
    corecore