Growth behavior of fibroblasts influenced by small changes in polymer structure

Polymers are a promising class of biomaterials that can be engineered to meet specific end use requirements. The order and processing history of the polymer, which would alter the molecular orientation of the material could have a significant contribution towards cellular attachment and in turn, cell growth on the particular polymer. Surface properties of the material were considered to directly influence the properties of the adherent cells including cellular growth and reorganization. The present study is aimed at comparing cell growth on polyarylates with that of polylactic acid in their original state or by introducing small changes in the surface structure of the polymers, by adopting different processing techniques (i.e. drawn and undrawn forms). Though, it is the most widely used scaffold, polylactic acid has been found to degrade faster and produce acidic end products, making it unsuitable for many applications. The two polyarylates chosen for the study were poly (DTD) dodecandioate and poly (DTE) adipate taken from the two extreme positions of the combinatorial library developed by Prof.J.Kohn. Thermal analysis techniques were used to study the molecular structure of the material. Higher degradation rate, less water uptake in the aqueous environment and less acidic end products were obtained from the two polyarylates as compared to polylactic acid. There was a significant difference in the growth rate of the fibroblasts on the drawn and the undrawn forms of the (12,10)-polyarylate, suggesting that its behavior could be correlated to the number of structural conversions existing in the polymer

VALIDATION OF DETACHED EDDY SIMULATION USING LESTOOL FOR HOMOGENEOUS TURBULENCE

Detached Eddy Simulation (DES) is a hybrid turbulence model, a modification to the one-equation model proposed by Spalart and Allmaras (1997) [26]. It combines the advantages of both the RANS and LES models to predict any fluid flow. Presently, the focus is on using Homogeneous Turbulence to test the DES model. In an attempt to scrutinize this model, many cases are considered involving the variance of DES grid spacing parameter, CDES, the grid density, Reynolds number and cases with different initial conditions. Choosing Homogeneous Turbulence for our study alienates complications related to the geometry, boundary conditions and other flow characteristics helping us in studying the behavior of the model thoroughly. Also, the interdependencies of the model grid spacing parameter, grid density and the numerical scheme used are also investigated. Many previous implementations of the DES model have taken the value of CDES=0.65. Through this work, many issues including the sensitivity of CDES will be made clear. The code used in running the test cases is called LESTool, developed at University of Kentucky, Lexington. The two main test cases considered are based on the benchmark experimental study by Comte Bellot and Corrsin (1971) [12] and the Direct Numerical Scheme (DNS) simulation by Blaisdell et al. (1991) [10]

PEMODELAN NUMERIK 1-D ADVEKSI-DISPERSI UNTUK MEMPREDIKSI KONSTRENTASI POLUTAN DALAM BADAN SUNGAI

Abstrak: Peran rekayasa Hidrologi dan Hidrolik dalam pengelolaan lingkungan menjadi amat penting dalam mengatasi permasalahan-permasalahan polutan di area perairan. Seperti telah kita ketahui bersama, pengujian kualitas air sungai membutuhkan biaya dan waktu yang cukup lama, selain itu untuk memperoleh informasi areal terpapar polutan tertentu sering kali mengalami kendala. Studi ini mencoba untuk mengatasi beberapa keterbatasan tersebut diatas dengan cara membuat pemodelan numeric 1-D adveksi-dispersi yang bertujuan untuk memprediksi konsenta-si polutan dalam badan sungai. Model numerik yang dikembangkan bertujuan untuk mempred-iksi transportasi massal kontaminan di badan sungai. Dalam melakukan analisa, metode yang digunakan adalah analisis 1 dimensi dan metode numerik menggunakan skema lax-wendroff . selain itu untuk memudahkan dalam pemodelan, dibuat model sungai rectangular dengan lebar saluran (B) 8 m, tinggi muka air (H) =0,4 m, kemiringan sungai ( so) = 0.00005, dan panjang saluran (L) = 150 km, serta dasar saluran adalah beton. Untuk mesimulasikan konsentrasi menggunakan finite difference schemes pada jarak 50 s.d 100 km, software yang digunakan ada-lah MATLAB serta menggunakan skema Lax-Wendroff (LW) untuk memecahkan Persamaan 1D Adveksi-Dispersi. Dari hasil pemodelan dapat disimpulkan terjadi pelebaran kurva konsen-trasi polutan akibat pengaruh dari hidrolika. Pada saat konsentrasi polutan tertinggi berada 50 km dari lokasi pembuangan limbah, area terpapar polutan 40 – 60 km, sedangkan pada jarak 100 km dari lokasi pembuangan limbah, area yang terpapar oleh polutan 80 – 120 km

Pengaruh Penyemprotan Air Panas, Asam Asetat Dan Asam La Ktat Terhadap Perkembangan Jumlah Mikroba Pada Karkas Kambing

Penelitian ini bertujuan mengetahui sejauh mana efektivitas air panas, asam asetat dan asam laktat dalam menghambat perkembangan mikroba pada karkas kambing. Paha kambing diperoleh dari rumah pemotongan hewan Ngampilan Yogyakarta. Masing-masing kelompok diberi perlakuan sebagai berikut : kelompok I tanpa penyemprotan (kontrol), kelompok II disemprot dengan asam asetat 1,8 %, kelompok III disemprot dengan dengan asam laktat 1,5 % (v/v), kelompok IV disemprot dengan air panas 80 °C diikuti asam laktat 1,5 % (v/v) dan kelompok V disemprot dengan asam asetat 1,8 % (vlv) diikuti dengan asam laktat 1,5 % (vlv). Hasil penelitian menunjukkan bahwa perkembangan jumlah total koliform pada kelompok kontrol lebih tinggi dibandingkan pada keempat kelompok perlakuan.. Perkembangan jumlah total koliform lebih tinggi pada kelompok asam laktat 1,5 %, kelompok asam asetat 1,8 % dibandingkan dengan kelompok kombinasi asam asetat 1,8 % dan asam laktat 1,5 % (P Key Word: Asam asetat,Air Panas,Asam laktat,Kilofor

Bridging the gap in public health education in India: the need of the hour

Background:Lack of proper communication skills among budding doctors is considered to be a major gap existing between teaching and practice of public health in various parts of India. Therefore a competency based teaching curriculum is needed to sharpen these skills necessary for bridging this gap and achieving a successful community based medical education.Methods:This cross-sectional study was conducted among a group of 28 students from a batch of 133 students in their fourth semester of second year undergraduate medical education, who attended their posting in the department of community medicine at JSS medical college (JSS University) in Mysore, for a period of one month during May 2014. A new educational intervention namely student’s short seminar was included in addition to their routine community medicine teaching curriculum. At the end of the postings a feedback regarding the intervention was collected from the students using a pretested structured questionnaire.Results:Questions related to the intervention were rated by the students in a six point Likert scale. The median total score was 15.0 (12-17). Among 28 students majority 16 (57.1%) of them had graded it as good while 11 (39.3%) had graded it as fair and 1 (3.6%) of them had graded it as poor based on the median total score.  Conclusion:Community based medical education can fulfil its purpose when it can advocate not only the cognitive domain (Knowledge) but also the affective domain (Attitudes) and psychomotor domain (Skills) of the learning process. Hence it is the foremost duty of the faculties in the department of community medicine in medical colleges to inculcate interest towards public health by introducing innovative and interactive teaching and learning interventions.