Enzyme-Catalyzed Synthesis and Characterization of Dihydroxystearic Acid Ester from Palm-Based Dihydroxystearic Acid and Monohydric Alcohol

Enzymatic synthesis of dihydroxystearic acid ester (DHSA ester) from dihydroxystearic acid (DHSA) and monohydric alcohol in organic solvent were investigated. Five commercial immobilized enzyme (Lipozyme 1M, Novozym 435, Termamyl, Savinase and Lipolase) were tested for their suitability for the reaction. Among the enzymes tested, Lipozyme 1M and Novozym 435 were chosen for optimization studies because of their higher specific activity. The effect of various reaction parameters such as time, temperature, organic solvent, amount of enzyme, mole ratio of substrates, thermodynamic water activity (aw) and structure of substrates were studied to determi ne optimal condition for the produ ction of DHSA ester. The optimal conditions for DHSA ester synthesis using Lipozyme 1M and Novozym 435 were obtained at reaction time of 3h, temperature of 50°C, mole ratio of substrates, 2.0 and amount of enzyme, 10-20% (w/w). The maxi m u m conversion for Lipozyme 1M and Novozym 435 at optimal condition was 92.4% and 94.9% respectively without removal of water in the reaction mixture. The results clearly demonstrated that both enzymes are well suited for the preparation of DHSA ester in organic media. This esterification reaction follows Michaelis-Menten kinetics as observed from the relationship of initial rate of the reaction, both as a function of enzyme and of substrate concentration. The kinetics of the enzymatic reaction is suggested to agree with a Ping-Pong Bi Bi mechanism. In a 5L batch reactor, up to 90% conversion was obtained at the optimal condition. Lipozyme 1M remained active after repeated used of 12 times. Characteristics and properties of DHSA ester were also eval uated, which include heat and colour stability, solubility, irritancy, dispersibility as well as emulsification properties. Purified DHSA ester showed higher heat stability compared to crude DHSA ester. Solubility of DHSA ester in methanol and ethanol is comparatively lower as compared to the solubility at higher chain length of alcohol. This compound is non-irritant to the skin. DHSA ester seems to have some emulsifying properties in water-in-oil system with high or low content of oil phase. The composition of the oil phase is important, as castor oil seems the most compatible oil. DHSA ester could be used as stabilizer or co-emulsifier in oil-in water emulsion system

a new payment by results method for determining the fair price of new oncological drugs

The high prices of new cancer drugs are likely to undermine national health services sustainability. As a solu tion to this problem, the "payment-by-results" method was proposed and nowadays this approach is commonly implemented by national drug agencies: the drug manufacturer is set to refund to the National Health Service the price of the drug if the benefits expected for the patient are not achieved. Based on the payment-by-results approach, we developed a new and easy to implement model, that can set a fair price, so that neither industry, nor National Health Service can obtain an undue gain. Obviously, this price can be modified by adjusting refund amounts to new healthcare and market conditions

Penyediaan dan Pencirian Resin Poli (Asid N-Fenilhidroksamik) Dari Poli (Metil Akrilat-Divinilbenzena)

Penukar ion pengkelat poli(asid N-fenilhidroksamik) telah disediakan dari poli(metil akrilat) terangkai silang dengan divinilbenzena. Pofuner permulaan disediakan melalui pempofuneran ampaian yang menghasilkan zarah-zarah dalam bentuk manik. Pengubahan polimer ini kepada resin poli(asid N-fenilhidroksamik) dibuat melalui tindakbalas dengan N-fenilhidroksilarnina di dalam larutan beratkali. Kesan parameter-parameter seperti nisbah N-fenilhidroksilamina terhadap polimer, tempoh masa tindakbalas, suhu dan kepekatan natrium hidroksida ke atas muatanmuatan hidrogen, kuprum(II) dan besi(III) resin telah juga dikaji. Keadaan optimum penyediaan adalah seperti berikut: suhu tindakbalas, 26.0-27.0°C; masa tindakbalas, 20.00 jam; kepekatan natrium hidroksida, 10.00M; pelarut, etanol-eter (2:1) dan nisbah N-fenilhidroksitamina-polimer, 1:1. Resin yang disediakan pada keadaan optimwn menuqjukkan muatan asid Nfeni1hidroksamik yang tinggi (2.41 mmol/g) dan kinetik yang baik (tl/l = 18.00 minit). Kepilihan resin ini tinggi terhadap ion-ion Au{III), Cu(II), Fe(III), Pb(II) dan Cr(III). Keluk muatan erapan melawan pH mencadangkan beberapa pemisahan ionion logam menggunakan penukar ion ini boleh dilakukan. Pengaruh beberapa eluen iaitu NaCl, CaCl₂, HCl dan NaOAC terhadap pengembangan atau pengecutan turns resin telah dikaji. Hasit kajian mencadangkan resin perlu dikondisi sewajarnya apabila digunakan di dalam turns untuk pemisahan dan pengekstrakan. Resin ini juga sesuai untuk pengekstrakan ion-ion Cu(II), Fe(III) dan Pb(II) dari larutan garam dan untuk mendapatkan semula ion Au(III) dari garam klorida

Is There a Role for Multiple Lines of Anti-HER2 Therapies Administered Beyond Progression in HER2-Mutated Non-Small Cell Lung Cancer? A Case Report and Literature Review

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Studi Komparasi Pemahaman Konsep Sistem Pernapasan Manusia Melalui Penerapan Pembelajaran Konstruktivisme tipe Novick Dipadu Concept Map dan Ceramah Bervariasi

This research is aim to find out the different comprehension of human respiration system concept in the Novick type of constructivism learning with concept map and the varied lecturing learning. This study was a quasi-experimental research using Post-test Only With Nonequivalent Groups research design. The sampling technique used was Cluster Sampling one. The populations of this research were all of 11th degree students of science at SMA Negeri 2 Karanganyar in academic year 2012/2013. The samples of this research were the students of 11th Imersi I as experiment group and 11th Imersi II as control group. Technique of collecting data used was a  multiple choice test with reasoning, essay test, and observation sheet. The hypothesis testing was carried out using t-test. The conclusion of research that there isn’t different comprehension of human respiratory system concept between the Novick type of constructivism learning with concept map and the varied lecturing learning. Keywords:     Concept map, Novick Type of Constructivism Learning, the Varied Lecturing, Comprehension of Human Respiration System Concep

RET Rearrangement as a Predictor of Unresponsiveness to Immunotherapy in Non-Small Cell Lung Cancer: Report of Two Cases with Review of the Literature

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Evaluation of Aflatoxin M1 Enrichment Factor in Semihard Cow's Milk Cheese and Correlation with Cheese Yield.

ABSTRACT The fate of aflatoxin M1 (AFM1) in cow's milk cheese produced from naturally contaminated raw milk was evaluated. Cow's milk, naturally contaminated by AFM1 at levels ranging from 0.020 to..

Five-years management of an emerging parasite risk (Eustrongylides sp., Nematoda) in a fishery supply chain located on Trasimeno Lake (Italy)

In the last few years, the widespread diffusion of potentially zoonotic parasitic nematodes of the genus Eustrongylides in the Trasimeno Lake, Central Italy, prompted Food Business Operators (FBOs) operating in the freshwater fish supply chain to define preventive measures to reduce or eliminate this new hazard from fishery products. The results of the self-checks for parasite risk management of a fishermen's cooperative over a five-year period (January 2016–April 2021) are presented. Nine freshwater commercial species, perch (Perca fluviatilis), largemouth black bass (Micropterus salmoides), big-scale sand smelt (Atherina boyeri), eel (Anguilla anguilla), black bullhead (Ictalurus melas), carp (Cyprinus carpio), tench (Tinca tinca), goldfish (Carassius auratus), and pumpkinseed sunfish (Lepomis gibbosus), differently processed (filleted, whole gutted or whole ungutted), were investigated. The presence of visible parasites was assessed by visual inspection during processing and recorded. Eustrongylides sp. were found in all species examined except for goldfish. Eustrongylides sp. occurrence was negligible in large mouth black bass, eel, carp, and tench, while increasing prevalence rates over the years were observed in fillets of perch <400 g (from 4.2% in 2016 to 68% in 2021), batches of sand smelt (<1%–40%) and pumpkinseed sunfish (6%–99%). Still low but slightly increasing prevalence rates were also observed for black bull head. The rising of the infection in perch, sand smelt, and pumpkinseed sunfish lead to a progressive implementation of preventive measures including the definition of a sampling plan for the visual inspection followed by trimming or removal of the parasites from the muscle or the application of a threshold value to define the marketability of fish batches. This is the first study describing an approach for the management of the emerging risk posed by nematodes of the genus Eustrongylides in a freshwater fishery supply chain. Besides providing an updated epidemiological scenario in Lake Trasimeno, where this parasite was described for the first time in Italy in 2015, it could support other FBOs in the implementation of preventive measures to safeguard consumers' health and trust