1,721,097 research outputs found
HUMAN PLACENTAL BETA-ENDORPHIN (HP-BETA-EP)
No full textThe previous finding that the placenta is capable of synthesising an
ACTH-like peptide, human chorionic corticotrophin (hCC)(l) and the observate
that both ACTH andP. EP are part of the same glycoprotein of 31K daltons in t~
p i tui tary (2) led us to investigate the presence of" EP in placental e x t r ac cs
Freshly collected, sliced ~nd cold saline Ivashed placenta was extractei
with acid acetone (l) to obtain a placental powder (PP)(5.8mg PP/g placenta'
protein content 460ug/mg) which was then tested EorfiEP in a radioreceptor
assay (RRA). For this assay 3H-D-ala-enkephalin was used a s t r a c e r and)lEP i.
Tris-HCl 50mM pH 7.4+Bacitracin 50ug/ml as standard. Membranes were obtaip.=~
by homogenisation of rat forebrains in 25 volumes of Tris-HCl (Polytron set =
for 15sec) a nd c e n t-r i f ug a t i o n at 15,000rpm x 15min (JA 20 ro t o r ) . The memb:--
anes were diluted with 5ml MnC12 60mM (frozen), 125ul Bacitracln stock solu:-
ion and 24.875ml 50Mrn Tris-HCl pH 7.4 buffer. Fo r the assay, 500).11. membrane
suspension, 100ul tracer, 100).1m standard or unknown sample and buffer up to ::.
mi were used. After 2hr incubation and shaking at 26°C, filtration was per:-
ormed on Millipore with cold buffer washing solution. PP prepared as above
gave a dilution curve p a r a l I e I to that oEPEP and a potency o f 5.15ngpEP/mb
PP protein. These re~ult$ re~ain qp~n çq criticis~ due to the lack of spec-
ificity of the RRA
Detecting and Explaining Usability Issues of Consumer Electronic Products
Full text linkUsability of a consumer electronic product (CEP) is one of the most important factors that the users consider in purchasing a CEP as well as functionality, price, etc. This has led many companies to realize new shapes of user interfaces (UIs) and styles of interaction for CEPs, ranging from modern touchscreens to physical controls and displays of any kind. Even if the general feeling is that such increased interactivity may enhance the overall user experience, the side effect is that often a CEP’s UI provides too many functions that are difficult to learn and use without referring to the user manual, leading to many usability issues. In this paper, we leverage a case study in the CEPs sector to present a novel log-based evaluation technique in the field of Human-Computer Interaction (HCI). Our technique allows us not only to keep track of the user interactions with a CEP’s UI during its daily use, but also to understand what has gone wrong during a user interaction, detecting which user actions have caused usability issues and suggesting explanations for solving them, thus providing a crucial feedback to improve the design of the CEP’s UI next version
[Effects of fasting, of weight reduction and realimentation on the endocrine-metabolic function of the obese subjects].
No full textDemonstration of receptor-mediated chemotaxis by human spermatozoa. A novel quantitative bioassay.
No full textA novel in vitro technique is described for measuring the chemotactic activity of soluble substances for human spermatozoa. This new bioassay has demonstrated that the synthetic chemotactic peptide N-formyl-Met-Leu-Phe elicits a potent, specific (i.e., receptor-mediated) chemotactic effect on human spermatozoa with an EC50 of 3.2 X 10(-10) M. Quantitative chemotactic studies on human spermatozoa with nine N-formylated-peptide analogs have shown a rank order of peptide potency indistinguishable (p less than 0.001) from that obtained in binding and chemotactic studies with rabbit neutrophils. The competitive antagonist Boc (t-butoxycarbonyl)-Phe-Leu-Phe-Leu-Phe, 10(-6) M, completely inhibited the chemotaxis elicited by f-Met-Leu-Phe, 10(-9) M, and was able to shift by one order of magnitude the molar concentration required by f-Met-Leu-Phe-Phe and f-Met-Leu-Phe to elicit the maximal response. The ability of N-formylated peptides to function as sperm chemoattractants reveals a high degree of correlation with binding, chemotaxis, and lysosomal enzyme release previously employed to define the neutrophil chemotactic receptor. This first unequivocal demonstration of substances having a receptor-mediated chemotactic effect for human male gametes suggests that human spermatozoa may indeed have the ability to respond chemotactically to appropriate environmental signals
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