Comparison of the thermal characteristics of connective tissue in loose structured and normal structured porcine M. semimembranosus

The aim of the present study was to characterise the thermal properties of connective tissue in loose structured porcine SM muscles in comparison to normal looking SM muscles and to see whether the meat quality traits were related to the properties of connective tissue. Samples from the muscles with loose structure and light colour were selected by visual assessment and normal looking SM muscles were used as a control (n = 25 loose structured + 25 control). The loose structured muscles had lower ultimate pH (pH_u) than the control muscles. The onset and peak temperatures of thermal shrinkage of intramuscular connective tissue (T_o and T_p, respectively) in loose structured muscles were similar to those of control muscles when the full set of data (25 loose structured + 25 control) were analysed. When the T_o and T_p data from muscles the exhibiting ten lowest and ten highest pH_u values were analysed, the low pH_u muscles (all classified as loose structured) had lower T_o and T_p than the high pH_u muscles (all classified as control) (p < 0.05). Drip loss of loose structured SM muscles (11.1%) was dramatically higher than that of control muscles (3.9%). Collagen content and collagen solubility were similar in loose structured and control muscles. It seemed that changes in the properties of intramuscular connective tissue were more easier found in porcine SM muscles with low pH_u than in SM muscles with high pH_u.     

Anti-Inflammatory Treatment with FTY720 Starting after Onset of Symptoms Reverses Synaptic Deficits in an AD Mouse Model

Therapeutic approaches providing effective medication for Alzheimer’s disease (AD) patients after disease onset are urgently needed. Previous studies in AD mouse models suggested that physical exercise or changed lifestyle can delay AD-related synaptic and memory dysfunctions when treatment started in juvenile animals long before onset of disease symptoms, while a pharmacological treatment that can reverse synaptic and memory deficits in AD mice was thus far not identified. Repurposing food and drug administration (FDA)-approved drugs for treatment of AD is a promising way to reduce the time to bring such medication into clinical practice. The sphingosine-1 phosphate analog fingolimod (FTY720) was approved recently for treatment of multiple sclerosis patients. Here, we addressed whether fingolimod rescues AD-related synaptic deficits and memory dysfunction in an amyloid precursor protein/presenilin-1 (APP/PS1) AD mouse model when medication starts after onset of symptoms (at five months). Male mice received intraperitoneal injections of fingolimod for one to two months starting at five to six months. This treatment rescued spine density as well as long-term potentiation in hippocampal cornu ammonis-1 (CA1) pyramidal neurons, that were both impaired in untreated APP/PS1 animals at six to seven months of age. Immunohistochemical analysis with markers of microgliosis (ionized calcium-binding adapter molecule 1; Iba1) and astrogliosis (glial fibrillary acid protein; GFAP) revealed that our fingolimod treatment regime strongly down regulated neuroinflammation in the hippocampus and neocortex of this AD model. These effects were accompanied by a moderate reduction of Aβ accumulation in hippocampus and neocortex. Our results suggest that fingolimod, when applied after onset of disease symptoms in an APP/PS1 mouse model, rescues synaptic pathology that is believed to underlie memory deficits in AD mice, and that this beneficial effect is mediated via anti-neuroinflammatory actions of the drug on microglia and astrocytes.     

IMPROVEMENTS IN THE SURFACE CHARACTERISTICS OF STAINLESS STEEL WORKPIECES BY BURNISHING WITH AN AMORPHOUS DIAMOND-COATED TIP

Burnishing is a cold working process that can be used to improve surface finish and surface hardness of workpieces. Conventionally, diamond or hard metal burnishing tools are used. In the present work, a novel burnishing tool was created by depositing amorphous diamond coating (AD) on a stainless steel tip. This tool was used to improve the surface finish and surface hardness of Nitronic-50 HS stainless steel workpieces. Nitronic-50 HS is used in a wide range of applications in industry. The burnishing process was carried out at different burnishing parameters (force, revolution speed, feed and number of tool passes). Burnishing parameters had a significant effect on the finishing process and they had to be optimized to achieve the best results. Remarkable improvements in surface finish (70% decrease in roughness) and hardness (25% increase) could be achieved with this tool and process in the surface finishing of Nitronic-50 stainless steel workpieces. From the tribological point of view, the AD-coated tip performed slightly better than a corresponding tip modified from a commercial polycrystalline diamond tip. AD coating seems to be very suitable for use in mechanical surface finishing tools such as a burnishing tip.     

Effects of preparation procedures,packaging and storage on nutrient retention in peeled potatoes

The effects of preparation procedures and packaging on vitamin C, dietary fibre, sugars, ash and moisture contents were studied in prepeeled packaged potatoes during two cultivation seasons. The potato cultivars Bintje, Van Gogh and Nicola were studied. Potatoes of the Nicola cultivar had the highest initial vitamin C and sugar contents. Retention of nutrient contents in packaged, prepeeled potatoes was very good after a 7-day storage period. Vitamin C contents were higher in packaged potatoes than in fresh tubers when ascorbic acid was used in the washing solution but the levels decreased during the 7-day storage period. When calcium chloride was added as well into the washing solution vitamin C contents remained high throughout the storage period. These results show that it is possible to preserve the nutritional contents of packaged potatoes over a 7-day storage period. Cooking decreased vitamin C contents by about 30% and keeping the potatoes hot for 1 h after cooking decreased vitamin C contents a further 10%. © 1998 SCI.     

Design of non-paraxial array illuminators by step-transition perturbation approach

Abstract

We introduce an efficient Fourier-domain formulation of an approximate method to model non-paraxial diffractive elements. The method is based on evaluation of local field perturbations caused by abrupt surface-profile transitions. It facilitates fast parametric optimization of binary and four-level diffractive array illuminators in the non-paraxial domain of diffractive optics. Comparison with rigorous electromagnetic theory of gratings shows that optimization with the perturbation method gives accurate results if the smallest feature size in the surface profile is larger than one wavelength. Some binary designs are demonstrated using electron beam lithography.     

Diffractive shaping of excimer laser beams

Abstract

We address the problem of shaping the intensity distribution of a highly directional partially coherent field, such as an excimer laser beam, by means of diffractive optics. Our theoretical analysis is based on modelling the multi-transverse-mode laser beam as a Gaussian Schell-model beam. It is shown numerically that a periodic element, which is unsuitable for the shaping of a coherent laser beam, works well with an excimer laser beam because of its partial spatial coherence. The conversion of an approximately Gaussian excimer laser beam into a flat-top beam in the Fourier plane of a lens is demonstrated with a diffractive beam shaper fabricated as a multilevel profile in SiOl by electron-beam lithography and proportional reactive-ion etching.     

The buffering capacity of porcine muscles

The aim of this study was to investigate the buffering capacity (BC) of five porcine muscles. The pH of muscles with zero lactate was also estimated. The BC was calculated on the basis of the amount of lactate accumulating in the muscle between two sampling times and the simultaneous pH decline. Two muscle samples were obtained from each muscle (n=13–36): one as soon as possible after slaughter and the other 24 h post-mortem. The BCs (mmol lactate/(pH kg)) were in the light gluteus superficialis, longissimus dorsi and semimembranosus muscles 48.3 ± 8.8, 48.6 ± 9.2 and 46.8 ± 13.0, and in the dark infraspinatus and masseter muscles 45.3 ± 13.1 and 32.0 ± 11.5, respectively. The dark masseter muscle differed significantly from the other muscles studied (p<0.01). The estimated pH values of muscles with zero lactate were in the gluteus, longissimus dorsi, semimembranosus muscles 7.14 ± 0.06; 7.18 ± 0.06; 7.38 ± 0.08, and in the infraspinatus and masseter muscles 6.87 ± 0.07; 7.03 ± 0.08, respectively. It was suggested since lactate is continuously formed in the muscles, the resting pH of living light and dark muscles may, however, be the same. The approach used in this study to determine the BC resulted in values which are close to values previously reported in the literature (measured by using titration curves).     

Controlling the crystallinity and roughness of atomic layer deposited titanium dioxide films

The surface roughness of thin films is an important parameter related to the sticking behaviour of surfaces in the manufacturing of microelectomechanical systems (MEMS). In this work, TiO2 films made by atomic layer deposition (ALD) with the TiCl4-H2O process were characterized for their growth, roughness and crystallinity as function of deposition temperature (110-300 degrees C), film thickness (up to approximately 100 nm) and substrate (thermal SiO2, RCA-cleaned Si, Al2O3). TiO2 films got rougher with increasing film thickness and to some extent with increasing deposition temperature. The substrate drastically influenced the crystallization behaviour of the film: for films of about 20 nm thickness, on thermal SiO2 and RCA-cleaned Si, anatase TiO2 crystal diameter was about 40 nm, while on Al2O3 surface the diameter was about a micrometer. The roughness could be controlled from 0.2 nm up to several nanometers, which makes the TiO2 films candidates for adhesion engineering in MEMS.     

The effect of cooling rate on beef tenderness: The significance of pH at 7 °C

To study the effects of cooling regime on beef tenderness, seven commercial beef slaughterhouses with different cooling regimes were selected to obtain different carcass cooling rates. The pH values and temperatures of 8 M. longissimus dorsi (LD) and M. semimembranosus (SM) muscles from each slaughterhouse were monitored for 30 h. The muscles of the monitored carcasses were excised and vacuum packed for Allo-Kramer shear force (SF) determinations. Samples were kept at 3-4 °C for 5 or 21 d. The slaughterhouses were grouped by their average pH values of the muscles, prevailing at the moment when the temperature of the muscles reached 7 °C. The pH groups for LD were (i) low (5.52-5.63), (ii) medium (5.84-5.97) and (iii) high (6.16-6.17). The highest shear forces were in group (iii), being the toughest: 155-152 N/g, and the lowest in group (i) (the most tender): 108-116 N/g, respectively. The regression equation or the shear force was SF=-295.4+73.0?(pH at 7 °C); (R(2)=87%). There was no significant correlation between the cooling rate and tenderness in SM, indicating that it is difficult to control the tenderness of all muscles using the same cooling regime. The ageing effect was more marked and the variation in the shear forces smaller in the slaughterhouses generating carcasses with low pH values at 7 °C than in those generating high ones. It was concluded that a low cooling rate, or more specifically, the temperature/pH at the onset of rigor mortis, is important for beef tenderness. The pH of LD must fall to values below 5.7 before/when the temperature reaches 7 °C.