1,140 research outputs found
Effects of cryoprotectant concentration and cooling rate on vitrification of aqueous solutions
Vitrification of aqueous cryoprotectant mixtures is essential in
cryopreservation of proteins and other biological samples. We report systematic
measurements of critical cryoprotective agent (CPA) concentrations required for
vitrification during plunge cooling from T=295 K to T=77 K in liquid nitrogen.
Measurements on fourteen common CPAs including alcohols (glycerol, methanol,
isopropanol), sugars (sucrose, xylitol, dextrose, trehalose), PEGs (ethylene
glycol, PEG 200, PEG 2 000, PEG 20 000), glycols (DMSO, MPD), and salt (NaCl)
were performed for volumes ranging over four orders of magnitude from ~nL to 20
mkL, and covering the range of interest in protein crystallography. X-ray
diffraction measurements on aqueous glycerol mixtures confirm that the
polycrystalline-to-vitreous transition occurs within a span of less than 2% w/v
in CPA concentration, and that the form of polycrystalline ice (hexagonal or
cubic) depends on CPA concentration and cooling rate. For most of the studied
cryoprotectants, the critical concentration decreases strongly with volume in
the range from ~5 mkL to ~0.1 mkL, typically by a factor of two. By combining
measurements of the critical concentration versus volume with cooling time
versus volume, we obtain the function of greatest intrinsic physical interest:
the critical CPA concentration versus cooling rate during flash cooling. These
results provide a basis for more rational design of cryoprotective protocols,
and should yield insight into the physics of glass formation in aqueous
mixtures.Comment: 8 pages, 6 jpg figure, 2 table
Effect of Feeding Pellets Containing Different Concentrate to wheat Straw Ratios on the Rumen Fermentation Characteristics of Awassi Lambs
اجريت الدراسة في منطقة السياحي- محافظة بابل للتحري عن تأثير تغذية نسب مختلفة من العلف المركز الى تبن الحنطة على خصائص تخمرات الكرش. حضرت خمسة علائق خليطة كلية تضمن تركيبها 30:70 و40:60 و 50:50 و 60:40 و 70:30 من العلف المركز الى تبن الحنطة كبست بصورة مكعبات وقدمت بصورة حرة الى الحملان العواسية. اظهرت النتائج ان زيادة نسبة العلف المركز الى الخشن قد ارتبطت بانخفاض معنوي (P<0.01) في الاس الهيدروجيني في سائل الكرش وسجلت اقل القيم, 6.60و 6.50 و 6.53 في النماذج المسحوبة من مجموعة الحملان المغذاة على المكعبات الحاوية على العلف المركز الى التبن بنسبة 50:50 و 60:40 و 70:30 على التوالي. كما تميزت تلك النماذج باقل (P<0.01) تركيز نيتروجين الامونيا, 4.85و 4.45 و 4.35 ملغم/100 مل, وأعلى (P<0.01) تركيز للأحماض الدهنية الطيارة الكلية.This study was carried out in Alsiyahii area– Babylon Province to investigate the effect of feeding Awassi lambs different ratios of concentrate: wheat straw (C: R) on rumen fermentation characteristics. Five pellets of total mixed rations (TMR) containing 30:70, 40:60, 50:50, 60:40 and 70:30 of C: R ratios were prepared and offered to lambs ad libitum. Results revealed that increasing C: R ratio was associated with a significant (P<0.01) reduction in pH, lower values of 6.60, 6.50 and 6.53 were recorded in samples of rumen liquor collected from lambs fed pellets containing C: R ratios of 50:50, 60:40 and 70:30, respectively. Those samples were also characterized with lower (P<0.01) concentration of ammonia nitrogen, 4.85, 4.45 and 4.38 mg/100 ml, and higher (P<0.01) concentration of total volatile fatty acids. 
Effect of Feeding Pellets Containing Different Concentrate to Wheat Straw Ratios on the Blood Parameters of Awassi Lambs
اجريت الدراسة للتحري عن تأثير تغذية الحملان العواسية على نسب مختلفة من العلف المركز الى تبن الحنطة على معايير الدم. حضرت مكعبات خمسة علائق خليطة كلية تضمن تركيبها 30:70 و40:60 و 50:50 و 60:40 و 70:30 من العلف المركز الى تبن الحنطة وقدمت بصورة حرة الى الحملان. اظهرت النتائج ان زيادة نسبة العلف المركز الى الخشن ادت الى حصول زيادة معنوية ((P<0.01 في تركيز الكلوكوز وسجلت اعلى القيم, 75.38 و 75.59 ملغم/100 مل في نماذج الدم المسحوبة من الحملان المغذاة على المكعبات الحاوية على العلف المركز الى التبن بنسبة 40:60 و 30:70 على التوالي. كما تميزت تلك النماذج بأعلى ((P<0.01 تركيز للبروتين الكلي والكليسريدات الثلاثية في الدم. اما تركيز نيتروجين اليوريا فقد سجلت اعلى ((P<0.01 القيم, 44.15 و 42.68 و 44.98 ملغم/100 مل في نماذج الدم المسحوبة من الحملان المغذاة على المكعبات الحاوية على العلف المركز الى التبن بنسبة 50:50 و 40:60 و 30:70 على التوالي.This study was carried out to investigate the effect of feeding Awassi lambs different ratios of concentrate: wheat straw (C: R) on blood parameters. Five pellets of total mixed rations (TMR) containing 30:70, 40:60, 50:50, 60:40 and 70:30 of C: R ratios were prepared and offered to lambs ad libitum. The results showed that increasing the C: R ratio significantly (P<0.01) increased the blood glucose. Higher concentration, 75.38 and 75.59 mg/100 ml were recorded in blood samples withdrawn from lambs fed on pellets containing 60:40 and 70:30 of C: R ratios respectively. similarly, those blood samples were characterized with higher (P<0.01) concentrations of total protein and triglycerides. With regard to urea nitrogen, higher (P<0.01) concentration, 44.15, 42.68 and 44.98 mg/100 ml were detected in blood samples withdrawn from lambs fed pellets containing 50:50, 60:40 and 70:30, respectively
Investigating the mechanism of acoustically activated uptake of drugs from Pluronic micelles
BACKGROUND: This paper examines the mechanism of ultrasonic enhanced drug delivery from Pluronic micelles. In previous publications by our group, fluorescently labeled Pluronic was shown to penetrate HL-60 cells with and without the action of ultrasound, while drug uptake was increased with the application of ultrasound. METHODS: In this study, the amount of uptake of two fluorescent probes, Lysosensor Green (a pH-sensitive probe) and Cell Tracker Orange CMTMR (a pH-independent probe), was measured in HL-60 and HeLa cells. RESULTS: The results of our experiments show that the increase in drug accumulation in the cells as a result of ultrasonication is not due to an increase in endocytosis due to ultrasonication. CONCLUSIONS: We hypothesize that sonoporation plays an important role in the acoustically activated drug delivery of chemotherapy drugs delivered from Pluronic micelles
Design and testing of a new microprocessor-based current differential protection scheme for teed circuits
Pregabalin Misuse and Abuse: A Scoping Review of Extant Literature
Prescribing of pregabalin is increasing worldwide with public health concerns centering on misuse and abuse of prescribed and diverted pregabalin. To describe and map what is known about misuse and abuse of pregabalin, a scoping review of available published literature was undertaken. A scoping review methodology was used to identify and map available literature on misuse and abuse of prescribed and diverted pregabalin. Four themes emerged on the misuse and abuse of pregabalin: (a) abuse potential, (b) prevalence of abuse, (c) risk and predisposition, and (d) consequences of abuse. Fifty-four records were reviewed and charted. Of note was the dearth of research on the topic prior to 2005, with increased interest in pregabalin abuse potential from 2010 onward. Available literature supports concern around abuse potential of pregabalin, especially among patients with a history of substance abuse. Prescribers should adopt more rational prescribing. © 2018, The Author(s) 2018
Use of evidence to support healthy public policy: a policy effectiveness-feasibility loop
Public policy plays a key role in improving population health and in the control of diseases, including non-communicable diseases.
However, an evidence-based approach to formulating healthy public policy has been difficult to implement, partly on account of barriers
that hinder integrated work between researchers and policy-makers. This paper describes a “policy effectiveness–feasibility loop” (PEFL) that
brings together epidemiological modelling, local situation analysis and option appraisal to foster collaboration between researchers and
policy-makers. Epidemiological modelling explores the determinants of trends in disease and the potential health benefits of modifying
them. Situation analysis investigates the current conceptualization of policy, the level of policy awareness and commitment among key
stakeholders, and what actually happens in practice, thereby helping to identify policy gaps. Option appraisal integrates epidemiological
modelling and situation analysis to investigate the feasibility, costs and likely health benefits of various policy options. The authors illustrate
how PEFL was used in a project to inform public policy for the prevention of cardiovascular diseases and diabetes in four parts of the eastern
Mediterranean. They conclude that PEFL may offer a useful framework for researchers and policy-makers to successfully work together to
generate evidence-based policy, and they encourage further evaluation of this approach
Maternal serum screening of Palestinian women in the West Bank
ABSTRACT An audit was made of laboratory records of triple test results from 943 Palestinian women residing in the West Bank from 2000-03. The mean expected age at delivery of the subjects was 25.5 years; 12% were 35 years old or above. Age was the main factor associated with an abnormal calculated risk score. The frequency of elevated serum alpha-fetoprotein was 1.3%, abnormal human choriogonic gonadotropin (elevated or reduced) was 1.9% and reduced unconjugated estriol was 0.3%. Dépistage sérologique maternel chez des Palestiniennes en Cisjordanie RÉSUMÉ On a procédé à un audit des dossiers de laboratoire pour les résultats du triple test de 943 Palestiniennes résidentes en Cisjordanie durant la période 2000-2003. L'âge moyen des sujets prévu à la date de l'accouchement était de 25,5 ans ; 12 % étaient âgés de 35 ans ou plus. L'âge était le principal facteur associé à un score de risque calculé anormal. La fréquence du taux élevé de l'alpha-foeto-protéine sérique était de 1,3 % ; pour la gonadotropine choriogonique humaine anormale (élévation ou diminution), la fréquence était de 1,9 %, et pour le taux diminué de l'estriol non conjugué de 0,3 %
Maternal serum screening of Palestinian women in the West Bank
ABSTRACT An audit was made of laboratory records of triple test results from 943 Palestinian women residing in the West Bank from 2000-03. The mean expected age at delivery of the subjects was 25.5 years; 12% were 35 years old or above. Age was the main factor associated with an abnormal calculated risk score. The frequency of elevated serum alpha-fetoprotein was 1.3%, abnormal human choriogonic gonadotropin (elevated or reduced) was 1.9% and reduced unconjugated estriol was 0.3%. Dépistage sérologique maternel chez des Palestiniennes en Cisjordanie RÉSUMÉ On a procédé à un audit des dossiers de laboratoire pour les résultats du triple test de 943 Palestiniennes résidentes en Cisjordanie durant la période 2000-2003. L'âge moyen des sujets prévu à la date de l'accouchement était de 25,5 ans ; 12 % étaient âgés de 35 ans ou plus. L'âge était le principal facteur associé à un score de risque calculé anormal. La fréquence du taux élevé de l'alpha-foeto-protéine sérique était de 1,3 % ; pour la gonadotropine choriogonique humaine anormale (élévation ou diminution), la fréquence était de 1,9 %, et pour le taux diminué de l'estriol non conjugué de 0,3 %
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