21 research outputs found
Pengaruh Disiplin Kerja dan Motivasi Terhadap Kinerja Pegawai pada Dinas Bangunan di Kabupaten Bekasi
Dalam penelitian ini bertujuan untuk menganalisis Pengaruh antara Disiplin dan Motivasi Terhadap Kinerja Pegawai Pada Dinas Bangunan di Kabupaten Bekasi. Penelitian ini mengambil sampel sebanyak 63 dari 71 Pegawai Dinas Bangunan Kabupaten Bekasi. Pengambilan sampel dilakukan dengan menggunakan metode stratifikasi random sampling. Analisis yang digunakan adalah regresi berganda dengan menggunakan batas signifikansi 0,05. Dalam penelitian ini diperoleh nilai fhitung sebesar 4,000. Jika dibandingkan ftabel sebesar 2,76 pada taraf signifikansi 5%, maka nilai fhitung > ftabel yaitu 4,000 > 2,76. Hasil ini menunjukkan bahwa terdapat pengaruh positif dan signifikan antara disiplin dan motivasi kerja secara bersama-sama terhadap kinerja pegawai di Dinas Bangunan Kabupaten Bekasi. Kemudian berdasarkan hasil perhitungan data dan analisis yang digunakan, diperoleh persamaan regresi yaitu: Y = 4,765+0,197X1+0,090 X2 serta nilai (R2) sebesar 0,409 atau 40,9%. Hasil ini menginformasikan bahwa kinerja pegawai dapat dijelaskan oleh variabel disiplin kerja pegawai dan motivasi kerja pegawai sebesar 40,9%. Nilai R2 adalah sebesar 40,9% hal ini menunjukkan bahwa adanya pengaruh X1 (Disiplin) dan X2 (Motivasi) secara bersama-sama (simultan) terhadap Y ( Kinerja )
PERBAIKAN POSTUR KERJA PROSES GANTI DIES CUTTING MENGGUNAKAN METODE RULA DAN REBA DI PT. DWA
PT. DWA merupakan industry manufactur berdiri sejak tahun 1978, bergerak di industri otomotif dengan produksi polyurethane, Reaction Injection Molding (rim), composite dan Plastic, memiliki beberapa proses yang menggunakan dies untuk melakukan proses produksi, dan dies untuk proses produksi diperlukan proses ganti dies, yang membutuhkan tenaga besar dan membutuhkan fokus dalam pengerjaannya, membuat postur tubuh mengalami tegang dan nyeri akibat postur kerja yang tidak baik. Perlu adanya analisis dengan tujuan mengetahui postur kerja operator melalui metode RULA (Rapid Upper Limb Assessment) dan REBA (Rapid Entire Body Assessment) yang akan di jadikan sebagai bahan pertimbangan perbaikan postur tubuh dalam bekerja, serta analisis yang dapat dilakukan dengan metode NBM (Nordic Body Map), RULA dan REBA, penggunaan metode ini didukung dengan kondisi operator ganti dies saat bekerja merasakan keluhan sakit pada tubuh, metode RULA dan REBA digunakan untuk analisis postur tubuh operator ganti dies untuk dilakukan perbaikan posisi postur tubuh pada saat melakukan aktivitas, berdasarkan pengolahan data yang telah dilakukan menunjukan bahwa skor NBM mendapatkan skor 64 dan RULA mendapatkan skor 7, serta REBA mendapatkan skor 12 artinya berdasarkan jawaban skor NBM memperoleh skor yang tinggi dikarenakan apa yang pekerja rasakan dengan postur kerja saat ini mengganggu aktivitasnya. Perubahan postur kerja harus dilakukan secepatnya berdasarkan pada skor penilaian RULA dan REBA. Perubahan yang harus segara dilakukan untuk mencegah terjadinya kelelahan postur tubuh yang berkepanjangan maka perlu adanya dibuatkan alat bantu angkat dies untuk meminimalisir terjadinya cedera. Kesimpulan dari penelitian ini adalah dengan adanya alat bantu angkat ini dapat memperbaiki postur tubuh
Pengaruh Disiplin Kerja dan Motivasi Terhadap Kinerja Pegawai pada Dinas Bangunan di Kabupaten Bekasi
Dalam penelitian ini bertujuan untuk menganalisis Pengaruh antara Disiplin dan Motivasi Terhadap Kinerja Pegawai Pada Dinas Bangunan di Kabupaten Bekasi. Penelitian ini mengambil sampel sebanyak 63 dari 71 Pegawai Dinas Bangunan Kabupaten Bekasi. Pengambilan sampel dilakukan dengan menggunakan metode stratifikasi random sampling. Analisis yang digunakan adalah regresi berganda dengan menggunakan batas signifikansi 0,05. Dalam penelitian ini diperoleh nilai fhitung sebesar 4,000. Jika dibandingkan ftabel sebesar 2,76 pada taraf signifikansi 5%, maka nilai fhitung > ftabel yaitu 4,000 > 2,76. Hasil ini menunjukkan bahwa terdapat pengaruh positif dan signifikan antara disiplin dan motivasi kerja secara bersama-sama terhadap kinerja pegawai di Dinas Bangunan Kabupaten Bekasi. Kemudian berdasarkan hasil perhitungan data dan analisis yang digunakan, diperoleh persamaan regresi yaitu: Y = 4,765+0,197X1+0,090 X2 serta nilai (R2) sebesar 0,409 atau 40,9%. Hasil ini menginformasikan bahwa kinerja pegawai dapat dijelaskan oleh variabel disiplin kerja pegawai dan motivasi kerja pegawai sebesar 40,9%. Nilai R2 adalah sebesar 40,9% hal ini menunjukkan bahwa adanya pengaruh X1 (Disiplin) dan X2 (Motivasi) secara bersama-sama (simultan) terhadap Y ( Kinerja )
Exposure to high-frequency electromagnetic field triggers rapid uptake of large nanosphere clusters by pheochromocytoma cells
Background: Effects of man-made electromagnetic fields (EMF) on living organisms potentially include transient and permanent changes in cell behaviour, physiology and morphology. At present, these EMF-induced effects are poorly defined, yet their understanding may provide important insights into consequences of uncontrolled (e.g., environmental) as well as intentional (e.g., therapeutic or diagnostic) exposure of biota to EMFs. In this work, for the first time, we study mechanisms by which a high frequency (18 GHz) EMF radiation affects the physiology of membrane transport in pheochromocytoma PC 12, a convenient model system for neuro-toxicological and membrane transport studies.
Methods and results: Suspensions of the PC 12 cells were subjected to three consecutive cycles of 30s EMF treatment with a specific absorption rate (SAR) of 1.17 kW kg-1, with cells cooled between exposures to reduce bulk dielectric heating. The EMF exposure resulted in a transient increase in membrane permeability for 9 min in up to 90 % of the treated cells, as demonstrated by rapid internalisation of silica nanospheres (diameter d ≈ 23.5 nm) and their clusters (d ≈ 63 nm). In contrast, the PC 12 cells that received an equivalent bulk heat treatment behaved similar to the untreated controls, showing lack to minimal nanosphere uptake of approximately 1-2 %. Morphology and growth of the EMF treated cells were not altered, indicating that the PC 12 cells were able to remain viable after the EMF exposure. The metabolic activity of EMF treated PC 12 cells was similar to that of the heat treated and control samples, with no difference in the total protein concentration and lactate dehydrogenase (LDH) release between these groups.
Conclusion: These results provide new insights into the mechanisms of EMF-induced biological activity in mammalian cells, suggesting a possible use of EMFs to facilitate efficient transport of biomolecules, dyes and tracers, and genetic material across cell membrane in drug delivery and gene therapy, where permanent permeabilisation or cell death is undesirable
Lethal Interactions of Atomically Precise Gold Nanoclusters and Pseudomonas aeruginosa and Staphylococcus aureus Bacterial Cells
International audienceUltrasmall metal nanoclusters (NCs) are employed in an array of diagnostic and therapeutic applications due to their tunable photoluminescence, high biocompatibility, polyvalent effect, ease of modification, and photothermal stability. However, gold nanoclusters' (AuNCs') intrinsically antimicrobial properties remain poorly explored and are not well understood. Here, we share an insight into the antimicrobial action of atomically precise AuNCs based on their ability to passively translocate across the bacterial membrane. Functionalized by a hydrophilic modified-bidentate sulfobetaine zwitterionic molecule (AuNC-ZwBuEt) or a more hydrophobic monodentate-thiolate, mercaptohexanoic acid (AuNC-MHA) molecule, 2 nm AuNCs were lethal to both Gram-negative Pseudomonas aeruginosa and Gram-positive Staphylococcus aureus bacteria. The bactericidal efficiency was found to be bacterial strain-, time-, and concentration-dependent. The direct visualizations of the translocation of AuNCs and AuNC-cell and subcellular interactions were investigated using cryo-soft X-ray nano-tomography, transmission electron microscopy (TEM), and scanning TEM energy-dispersive spectroscopy analyses. AuNC-MHA were identified in the bacterial cytoplasm within 30 min, without evidence of the loss of membrane integrity. It is proposed that the bactericidal effect of AuNCs is attributed to their size, which allows for efficient energy-independent translocation across the cell membrane. The internalization of both AuNCs caused massive internal damage to the cells, including collapsed subcellular structures and altered cell morphology, leading to the eventual loss of cellular integrity
PC 12 Pheochromocytoma Cell Response to SuperHigh Frequency Terahertz Radiation fromSynchrotron Source
High frequency (HF) electromagnetic fields (EMFs) have been widely used in many wireless communication devices, yet within the terahertz (THz) range, their effects on biological systems are poorly understood. In this study, electromagnetic radiation in the range of 0.3-19.5 x 10 12 Hz, generated using a synchrotron light source, was used to investigate the response of PC 12 neuron-like pheochromocytoma cells to THz irradiation. The PC 12 cells remained viable and physiologically healthy, as confirmed by a panel of biological assays; however, exposure to THz radiation for 10 min at 25.2 ± 0.4 ◦ C was sufficient to induce a temporary increase in their cell membrane permeability. High-resolution transmission electron microscopy (TEM) confirmed cell membrane permeabilization via visualisation of the translocation of silica nanospheres (d = 23.5 ± 0.2 nm) and their clusters (d = 63 nm) into the PC 12 cells. Analysis of scanning electron microscopy (SEM) micrographs revealed the formation of atypically large (up to 1 µm) blebs on the surface of PC 12 cells when exposed to THz radiation. Long-term analysis showed no substantial differences in metabolic activity between the PC 12 cells exposed to THz radiation and untreated cells; however, a higher population of the THz-treated PC 12 cells responded to the nerve growth factor (NGF) by extending longer neurites (up to 0-20 µm) compared to the untreated PC12 cells (up to 20 µm). These findings present implications for the development of nanoparticle-mediated drug delivery and gene therapy strategies since THz irradiation can promote nanoparticle uptake by cells without causing apoptosis, necrosis or physiological damage, as well as provide a deeper fundamental insight into the biological effects of environmental exposure of cells to electromagnetic radiation of super high frequencies
Exposure to high-frequency electromagnetic field triggers rapid uptake of large nanosphere clusters by pheochromocytoma cells
Palalle G Tharushi Perera,1 The Hong Phong Nguyen,2 Chaitali Dekiwadia,3 Jason V Wandiyanto,1 Igor Sbarski,1 Olga Bazaka,4 Kateryna Bazaka,5 Russell J Crawford,4 Rodney J Croft,6 Elena P Ivanova4 1Faculty of Science, Engineering and Technology, Swinburne University of Technology, Hawthorn, VIC, Australia; 2Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam; 3RMIT Microscopy and Microanalysis Facility, College of Science, Engineering and Health, RMIT University, Melbourne, VIC, Australia; 4School of Science, RMIT University, Melbourne, VIC, Australia; 5School of Chemistry, Physics, Mechanical Engineering, Queensland University of Technology, Brisbane, QLD, Australia; 6School of Psychology, Illawarra Health and Medical Research Institute, University of Wollongong, Wollongong, NSW, Australia Background: Effects of man-made electromagnetic fields (EMF) on living organisms potentially include transient and permanent changes in cell behaviour, physiology and morphology. At present, these EMF-induced effects are poorly defined, yet their understanding may provide important insights into consequences of uncontrolled (e.g., environmental) as well as intentional (e.g., therapeutic or diagnostic) exposure of biota to EMFs. In this work, for the first time, we study mechanisms by which a high frequency (18 GHz) EMF radiation affects the physiology of membrane transport in pheochromocytoma PC 12, a convenient model system for neurotoxicological and membrane transport studies. Methods and results: Suspensions of the PC 12 cells were subjected to three consecutive cycles of 30s EMF treatment with a specific absorption rate (SAR) of 1.17 kW kg-1, with cells cooled between exposures to reduce bulk dielectric heating. The EMF exposure resulted in a transient increase in membrane permeability for 9 min in up to 90 % of the treated cells, as demonstrated by rapid internalisation of silica nanospheres (diameter d ≈ 23.5 nm) and their clusters (d ≈ 63 nm). In contrast, the PC 12 cells that received an equivalent bulk heat treatment behaved similar to the untreated controls, showing lack to minimal nanosphere uptake of approximately 1–2 %. Morphology and growth of the EMF treated cells were not altered, indicating that the PC 12 cells were able to remain viable after the EMF exposure. The metabolic activity of EMF treated PC 12 cells was similar to that of the heat treated and control samples, with no difference in the total protein concentration and lactate dehydrogenase (LDH) release between these groups. Conclusion: These results provide new insights into the mechanisms of EMF-induced biological activity in mammalian cells, suggesting a possible use of EMFs to facilitate efficient transport of biomolecules, dyes and tracers, and genetic material across cell membrane in drug delivery and gene therapy, where permanent permeabilisation or cell death is undesirable. Keywords: electromagnetic fields, EMFs, 18 GHz, PC 12 neuronal cells, membrane permeability, microwav
Outsmarting superbugs: Bactericidal activity of nanostructured titanium surfaces against methicillin- and gentamicin-resistant Staphylococcus aureus ATCC 33592
The colonisation of biomaterial surfaces by pathogenic bacteria is a significant issue of concern, particularly in light of the rapid rise of antibiotic resistance. Current strategies are proving ineffective as multi-drug resistant pathogenic bacteria emerge. Recently, it was discovered that surfaces with nanoscale features are capable of physically rupturing bacteria and hence displaying mechano-bactericidal activity. In this study, we investigated the interactions between methicillin- and gentamicin-susceptible and -resistant Staphylococcus aureus strains and nanostructured titanium surfaces, fabricated using a hydrothermal etching process. The nanostructured titanium surfaces proved to be equally effective and highly bactericidal against both the susceptible and resistant S. aureus strains, with killing efficiencies of 80.7% ± 12.0 and 86.8% ± 11.6, respectively. The mechano-bactericidal activity of these nanostructured titanium surfaces offers an innovative solution to establish medical device surfaces with antimicrobial activity in the context of increasing antibiotic resistance
Exposure to high-frequency electromagnetic field triggers rapid uptake of large nanosphere clusters by pheochromocytoma cells
Background: Effects of man-made electromagnetic fields (EMF) on living organisms potentially include transient and permanent changes in cell behaviour, physiology and morphology. At present, these EMF-induced effects are poorly defined, yet their understanding may provide important insights into consequences of uncontrolled (e.g., environmental) as well as intentional (e.g., therapeutic or diagnostic) exposure of biota to EMFs. In this work, for the first time, we study mechanisms by which a high frequency (18 GHz) EMF radiation affects the physiology of membrane transport in pheochromocytoma PC 12, a convenient model system for neurotoxicological and membrane transport studies.
Methods and results: Suspensions of the PC 12 cells were subjected to three consecutive cycles of 30s EMF treatment with a specific absorption rate (SAR) of 1.17 kW kg(-1), with cells cooled between exposures to reduce bulk dielectric heating. The EMF exposure resulted in a transient increase in membrane permeability for 9 min in up to 90 % of the treated cells, as demonstrated by rapid internalisation of silica nanospheres (diameter d approximate to 23.5 nm) and their clusters (d approximate to 63 nm). In contrast, the PC 12 cells that received an equivalent bulk heat treatment behaved similar to the untreated controls, showing lack to minimal nanosphere uptake of approximately 1-2 %. Morphology and growth of the EMF treated cells were not altered, indicating that the PC 12 cells were able to remain viable after the EMF exposure. The metabolic activity of EMF treated PC 12 cells was similar to that of the heat treated and control samples, with no difference in the total protein concentration and lactate dehydrogenase (LDH) release between these groups.
Conclusion: These results provide new insights into the mechanisms of EMF-induced biological activity in mammalian cells, suggesting a possible use of EMFs to facilitate efficient transport of biomolecules, dyes and tracers, and genetic