1,640 research outputs found

    In situ synthesis of size-controlled, stable silver nanoparticles within ultrashort peptide hydrogels and their anti-bacterial properties

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    We have developed a silver-releasing biomaterial with promising potential for wound healing applications. The material is made of ultrashort peptides which can self-assemble in water to form hydrogels. Silver nanoparticles (Ag NPs) were synthesized in situ within the biomaterial, using only UV irradiation and no additional chemical reducing agents. The synthetic strategy allows precise control of the nanoparticle size, with the network of peptide fibers preventing aggregation of Ag NPs. The biomaterial shows increased mechanical strength compared to the hydrogel control. We observed a sustained release of Ag NPs over a period of 14 days. This is a crucial prerequisite for effective anti-bacterial therapy. The ability to inhibit bacterial growth was tested using different bacterial strains, namely gram-negative Escherichia coli and Pseudomonas aeruginosa and gram-positive Staphylococcus aureus. Inhibition of bacterial growth was observed for all strains. The best results were obtained for Pseudomonas aeruginosa which is known for exhibiting multidrug resistance. Biocompatibility studies on HDFa cells, using Ag NP-containing hydrogels, did not show any significant influence on cell viability. We propose this silver-releasing hydrogel as an excellent biomaterial with great potential for applications in wound healing due to its low silver content, sustained silver nanoparticle release and biocompatibility

    Implementasi Program CSR Lingkungan PT. Semen Baturaja (Persero) Tbk Terhadap Kondisi Sosial Ekonomi Masyarakat Di Kabupaten Ogan Komering Ulu Sumatera Selatan

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    CSR (Corporate Social Responsibility) lingkungan merupakan tindakan atau konsep yang dilakukan oleh Perusahaan (sesuai kemampuan Perusahaan tersebut) sebagai bentuk tanggungjawab mereka terhadap sosial dan lingkungan sekitar dimana Perusahaan itu berada. Menurut Anatan (2008), CSR merupakan salah satu wujud partisipasi dunia USAha untuk mengembangkan program kepedulian Perusahaan kepada masyarakat sekitar melalui penciptaan dan pemeliharaan keseimbangan antara mencetak keuntungan, fungsi-fungsi sosial dan pemeliharaan lingkungan hidup. Penelitian ini termasuk penelitian deskriptif dengan metode survey. Sampel penelitian berjumlah 382 Kepala Keluarga (KK) dengan teknik pengambilan sampel adalah stratified random sampling. Data disajikan dalam bentuk grafik serta narasi untuk menginterpretasikan data tersebut. Hasil penelitian menunjukkan bahwa berdasarkan skor jawaban responden implementasi program CSR lingkungan PT Semen Baturaja (Persero) Tbk yang selalu dan sering dilakukan di Kelurahan Sukajadi, Air Gading, Talang Jawa, Saung Naga, Tanjung Agung, Pusar dan Batu Kuning adalah pada indikator program pengembangan prasarana keagamaan dan fasilitas umum dan indikator program pemberian bantuan korban bencana alam. Dapat disimpulkan bahwa Implementasi program CSR Lingkungan PT Semen Baturaja (Persero) Tbk berpengaruh terhadap kondisi sosial ekonomi masyarakat di wilayah ring I Kabupaten Ogan Komering Ulu. Saran penelitian adalah perlu dibuat strategi kebijakan pembuatan program CSR Lingkungan PT Semen Baturaja yang lebih memperhatikan nilai lokal masyarakat, agar efektifitas dan efisiensi program dapat dicapa

    Spinal Manipulation vs Sham Manipulation for Nonspecific Low Back Pain:A Systematic Review and Meta-Analysis

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    OBJECTIVE: The purpose of this systematic review was to identify and critically evaluate randomized controlled trials of spinal manipulation (SM) vs sham manipulation in the treatment of nonspecific low back pain. METHODS: Four electronic databases were searched from their inception to March 2015 to identify all relevant trials. Reference lists of retrieved articles were hand-searched. All data were extracted by 2 independent reviewers, and risk of bias was assessed using the Cochrane Back Review Group Risk of Bias tool. RESULTS: Nine randomized controlled trials were included in the systematic review, and 4 were found to be eligible for inclusion in a meta-analysis. Participants in the SM group had improved symptoms compared with participants receiving sham treatment (standardized mean difference = − 0.36; 95% confidence interval, − 0.59 to − 0.12). The majority of studies were of low risk of bias; however, several of the studies were small, the practitioner could not be blinded, and some studies did not conduct intention-to-treat analysis and had a high level of dropouts. CONCLUSION: There is some evidence that SM has specific treatment effects and is more effective at reducing nonspecific low back pain when compared with an effective sham intervention. However, given the small number of studies included in this analysis, we should be cautious of making strong inferences based on these results

    Pattern languages in HCI: A critical review

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    This article presents a critical review of patterns and pattern languages in human-computer interaction (HCI). In recent years, patterns and pattern languages have received considerable attention in HCI for their potential as a means for developing and communicating information and knowledge to support good design. This review examines the background to patterns and pattern languages in HCI, and seeks to locate pattern languages in relation to other approaches to interaction design. The review explores four key issues: What is a pattern? What is a pattern language? How are patterns and pattern languages used? and How are values reflected in the pattern-based approach to design? Following on from the review, a future research agenda is proposed for patterns and pattern languages in HCI

    The NASA Tournament Laboratory (NTL): Improving Data Access at PDS while Spreading Joy and Engaging Students through 16 Micro-Contests

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    NASA PDS hosts terabytes of valuable data from hundreds of data sources and spans decades of research. Data is stored on flat-file systems regulated through careful meta dictionaries. PDS's data is available to the public through its website which supports data searches through drill-down navigation. While the system returns data quickly, result sets in response to identical input differ depending on the drill-down path a user follows. To correct this Issue, to allow custom searching, and to improve general accessibility, PDS sought to create a new data structure and API, and to use them to build applications that are a joy to use and showcase the value of the data to students, teachers and citizens. PDS engaged TopCoder and Harvard Business School through the NTL to pursue these objectives in a pilot effort. Scope was limited to Small Bodies Node data. NTL analyzed data, proposed a solution, and implemented it through a series of micro-contests. Contest focused on different segments of the problem; conceptualization, architectural design, implementation, testing, etc. To demonstrate the utility of the completed solution, NTL developed web-based and mobile applications that can compare targets, regardless of mission. To further explore the potential of the solution NTL hosted "Mash-up" challenges that integrated the API with other publically available assets, to produce consumer and teaching applications, including an Augmented Reality iPad tool. Two contests were also posted to middle and high school students via the NoNameSite.com platform, and as a result of these contests, PDS/SBN has initiated a Facebook program. These contests defined and implemented a data warehouse with the necessary migration tools to transform legacy data, produced a public web interface for the new search, developed a public API, and produced four mobile applications that we expect to appeal to users both within and, without the academic community

    Megamaser Disks Reveal a Broad Distribution of Black Hole Mass in Spiral Galaxies

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    We use new precision measurements of black hole masses from water megamaser disks to investigate scaling relations between macroscopic galaxy properties and supermassive black hole (BH) mass. The megamaser-derived BH masses span 10^6-10^8 M_sun, while all the galaxy properties that we examine (including stellar mass, central mass density, central velocity dispersion) lie within a narrow range. Thus, no galaxy property correlates tightly with M_BH in ~L* spiral galaxies. Of them all, stellar velocity dispersion provides the tightest relation, but at fixed sigma* the mean megamaser M_BH are offset by -0.6+/-0.1 dex relative to early-type galaxies. Spiral galaxies with non-maser dynamical BH masses do not show this offset. At low mass, we do not yet know the full distribution of BH mass at fixed galaxy property; the non-maser dynamical measurements may miss the low-mass end of the BH distribution due to inability to resolve the spheres of influence and/or megamasers may preferentially occur in lower-mass BHs.Comment: 6 pages, 4 figures, replaced to fix error: NGC 4594 is not a maser galax
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