236 research outputs found

    Analisis Perhitungan Kapasitas Dehumidifier di Gudang Phonska Departemen Rancang Bangun PT Petrokimia Gresik

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    PT Petrokimia Gresik adalah salah satu produsen pupuk yang berlokasi di Kota Gresik, Jawa Timur yang memproduksi berbagai jenis pupuk. Beberapa jenis pupuk yang diproduksi, seperti pupuk Urea (SNI 02-2801-1998), pupuk Phonska Plus (SNI 2803-2012) dan pupuk Majemuk NPK (SNI 02-2803-2000) mempunyai sifat higroskopis. Pupuk yang memiliki sifat higroskopis akan mudah mencair dan menggumpal jika diletakkan di tempat terbuka. Oleh karena itu, pupuk harus disimpan dengan penanganan yang baik supaya kualitasnya tetap terjaga. Salah satu upaya untuk mengatasi masalah tersebut adalah dengan penggunaan dehumidifier di dalam gudang. Dehumidifier ini digunakan untuk mengontrol kelembapan dan temperatur di dalam gudang penyimpanan pupuk. Penelitian ini bertujuan untuk menganalisis kebutuhan dehumidifier yang akan dipasang di gudang penyimpanan pupuk Phonska berdasarkan total jumlah panas yang hilang dan kelembapan. Total panas yang hilang (total heat loss) di dalam gudang dihitung dan menghasilkan keluaran berupa spesifikasi dehumidifier yang sesuai dengan kebutuhan di gudang penyimpanan pupuk Phonska PT Petrokimia Gresik. Penelitian ini menghasilkan spesifikasi air heater dan air blower yang dibutuhkan adalah sebesar 200.000 kCal/hr dan 40.000 m3/hr. Selanjutnya, total kelembapan gudang Phonska PT Petrokimia Gresik adalah sebesar 66,1502 L/hari, sehingga dehumidifier harus dapat menyerap kelembapan sebesar jumlah tersebut

    Diversity of Actinomycetes From Eka Karya Botanical Garden, Bali

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    A total of 229 strains of actinomycetes were isolated and identified by full sequence of 16S rRNA gene analysis. Samples consisted of 18 soil and 20 leaf-litter were collected from Eka Karya Botanical Garden, Bali Island, Indonesia. Two isolation methods, i.e. SDS-Yeast Extract (SY) and Rehydration-Centrifugation (RC) were used in this study. Based on 16S rRNA gene analysis, isolated actinomycetes may be grouped into 28 genera. Based on molecular analysis of 16S rRNA gene similarities showed that isolated actinomycetes of Eka Karya Botanical Garden origin is diverse. Analysis on 144 isolates from soil samples, resulted in 24 genera and more than 87 species. Streptomyces is the most dominant genus where 65 isolates or 45% from isolated actinomycetes belong to this genus. It was followed by Actinoplanes (25 isolates =17%). From leaf-littersamples, the total number of 85 isolates may be grouped into 9 genera and more than 41 species. The most dominated genus is Actinoplanes (42 isolates =49%) followed by Catenuloplanes (16 isolates=19%)

    A novel bioengineered functional motor unit platform to study neuromuscular interaction

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    Background: In many neurodegenerative and muscular disorders, and loss of innervation in sarcopenia, improper reinnervation of muscle and dysfunction of the motor unit (MU) are key pathogenic features. In vivo studies of MUs are constrained due to difficulties isolating and extracting functional MUs, so there is a need for a simplified and reproducible system of engineered in vitro MUs. Objective: to develop and characterise a functional MU model in vitro, permitting the analysis of MU development and function. Methods: an immortalised human myoblast cell line was co-cultured with rat embryo spinal cord explants in a serum-free/growth fact media. MUs developed and the morphology of their components (neuromuscular junction (NMJ), myotubes and motor neurons) were characterised using immunocytochemistry, phase contrast and confocal microscopy. The function of the MU was evaluated through live observations and videography of spontaneous myotube contractions after challenge with cholinergic antagonists and glutamatergic agonists. Results: blocking acetylcholine receptors with α-bungarotoxin resulted in complete, cessation of myotube contractions, which was reversible with tubocurarine. Furthermore, myotube activity was significantly higher with the application of L-glutamic acid. All these observations indicate the formed MU are functional. Conclusion: a functional nerve-muscle co-culture model was established that has potential for drug screening and pathophysiological studies of neuromuscular interactions

    Simplified in vitro engineering of neuromuscular junctions between rat embryonic motoneurons and immortalized human skeletal muscle cells

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    Background: Neuromuscular junctions (NMJs) consist of the presynaptic cholinergic motoneuron terminals and the corresponding postsynaptic motor endplates on skeletal muscle fibers. At the NMJ the action potential of the neuron leads, via release of acetylcholine, to muscle membrane depolarization that in turn is translated into muscle contraction and physical movement. Despite the fact that substantial NMJ research has been performed, the potential of in vivo NMJ investigations is inadequate and difficult to employ. A simple and reproducible in vitro NMJ model may provide a robust means to study the impact of neurotrophic factors, growth factors, and hormones on NMJ formation, structure, and function. Methods: This report characterizes a novel in vitro NMJ model utilizing immortalized human skeletal muscle stem cells seeded on 35 mm glass-bottom dishes, cocultured and innervated with spinal cord explants from rat embryos at ED 13.5. The cocultures were fixed and stained on day 14 for analysis and assessment of NMJ formation and development. Results: This unique serum-and trophic factor-free system permits the growth of cholinergic motoneurons, the formation of mature NMJs, and the development of highly differentiated contractile myotubes, which exhibit appropriate configuration of transversal triads, representative of in vivo conditions. Conclusion: This coculture system provides a tool to study vital features of NMJ formation, regulation, maintenance, and repair, as well as a model platform to explore neuromuscular diseases and disorders affecting NMJs

    Structural Modeling and DNA Binding Autoinhibition Analysis of Ergp55, a Critical Transcription Factor in Prostate Cancer

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    BACKGROUND: The Ergp55 protein belongs to Ets family of transcription factor. The Ets proteins are highly conserved in their DNA binding domain and involved in various development processes and regulation of cancer metabolism. To study the structure and DNA binding autoinhibition mechanism of Ergp55 protein, we have produced full length and smaller polypeptides of Ergp55 protein in E. coli and characterized using various biophysical techniques. RESULTS: The Ergp55 polypeptides contain large amount of α-helix and random coil structures as measured by circular dichorism spectroscopy. The full length Ergp55 forms a flexible and elongated molecule as revealed by molecular modeling, dynamics simulation and structural prediction algorithms. The binding analyses of Ergp55 polypeptides with target DNA sequences of E74 and cfos promoters indicate that longer fragments of Ergp55 (beyond the Ets domain) showed the evidence of auto-inhibition. This study also revealed the parts of Ergp55 protein that mediate auto-inhibition. SIGNIFICANCE: The current study will aid in designing the compounds that stabilize the inhibited form of Ergp55 and inhibit its binding to promoter DNA. It will contribute in the development of drugs targeting Ergp55 for the prostate cancer treatment

    Can a standard dose of eicosapentaenoic acid (EPA) supplementation reduce the symptoms of delayed onset of muscle soreness?

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    Unaccustomed exercise can result in delayed onset of muscle soreness (DOMS) which can affect athletic performance. Although DOMS is a useful tool to identify muscle damage and remodelling, prolonged symptoms of DOMS may be associated with the over-training syndrome. In order to reduce the symptoms of DOMS numerous management strategies have been attempted with no significant effect on DOMS-associated cytokines surge. The present study aimed to investigate the acute and chronic effects of a 2x180 mg per day dose of eicosapentaenoic acid (EPA) on interleukin-6 (IL-6) mediated inflammatory response and symptoms associated with DOMS. Methods: Seventeen healthy non-smoking females (age 20.4 +/- 2.1 years, height 161.2 +/- 8.3cm and mass 61.48 +/- 7.4kg) were randomly assigned to either placebo (N = 10) or EPA (N = 7). Serum IL-6, isometric and isokinetic (concentric and eccentric) strength, and rating of perceived exertion (RPE) were recorded on four occasions: i-prior to supplementation, ii-immediately after three weeks of supplementation (basal effects), iii-48 hours following a single bout of resistance exercise (acute training response effects), and iv-48 hours following the last of a series of three bouts of resistance exercise (chronic training response effects). Results: There was only a group difference in the degree of change in circulating IL-6 levels. In fact, relative to the first baseline, by the third bout of eccentric workout, the EPA group had 103 +/- 60% increment in IL-6 levels whereas the placebo group only had 80 +/- 26% incremented IL-6 levels (P = 0.020). We also describe a stable multiple linear regression model which included measures of strength and not IL-6 as predictors of RPE scale. Conclusion: The present study suggests that in doubling the standard recommended dose of EPA, whilst this may still not be beneficial at ameliorating the symptoms of DOMS, it counter intuitively appears to enhance the cytokine response to exercise. In a context where previous in vitro work has shown EPA to decrease the effects of inflammatory cytokines, it may in fact be that the doses required in vivo is much larger than current recommended amounts. An attempt to dampen the exercise-induced cytokine flux in fact results in an over-compensatory response of this system
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