ABSTRACT
BACKGROUND: Survival rates after sudden cardiac arrest could be increased if bystanders could be encouraged to perform CPR until emergency services arrive. This should be initiated by the dispatcher at the emergency control facility who receives the call. For the first time the ERC guidelines of 2010 included instructions to be given to untrained rescuers by the dispatcher. Rapid recognition of cardiac arrest and initiation of emergency measures is assured by means of specific training for the dispatchers. AIM: The aim of this investigation was to determine whether the time between an emergency call and beginning of cardiopulmonary resuscitation (CPR) could be shortened using a simple protocol and whether a relationship exists between the intensity of phone contact between dispatcher and caller and if this improves the results. MATERIALS AND METHODS: In known cases of unconsciousness, group 1 (45 persons) received short CPR instructions via the phone, where the dispatcher was on the phone for continuous advice until emergency services arrived. Group 2 (45 persons) received identical phone instructions like group 1, but the phone call was terminated by the dispatcher after the information was provided. Group 3 (29 persons) only received instructions to start CPR. RESULTS: On average, all test persons in group 1 started reanimation after 68.0 ± 33.5 s, in group 2 after 68.3 ± 25.2 s, and in group 3 after 64.9 ± 34.4 s. The compression frequency on average was 98.3/min in group 1, 84.8/min in group 2, and 85.2/min in group 3; therefore, all groups reached an average frequency of > 80/min. The correct compression depth was achieved by 47.8 % of test persons in group 1, by 44.2 % in group 2, and by 30.2 % in group 3. All volunteers felt well supported. Of the 90 people, 70 did not feel that they were missing instructions. DISCUSSION: There were no significant differences between the groups regarding the target variables. The results show that already extremely short instructions or advice by the dispatcher to start CPR is sufficient to encourage bystanders to give assistance in an emergency. Continuous support over the phone does not appear to be necessary.
Subject(s)
Cardiopulmonary Resuscitation/education , Cardiopulmonary Resuscitation/methods , Emergency Medical Service Communication Systems , Emergency Service, Hospital , Heart Massage/methods , Out-of-Hospital Cardiac Arrest/therapy , Adult , Algorithms , Clinical Protocols , Early Medical Intervention , Female , Guideline Adherence , Humans , Male , Manikins , Middle Aged , Out-of-Hospital Cardiac Arrest/diagnosis , Out-of-Hospital Cardiac Arrest/mortality , Survival Rate , Time and Motion StudiesABSTRACT
We developed a spin transport model for a diffusive channel with coupled localized states that result in an effective increase of spin precession frequencies and a reduction of spin relaxation times in the system. We apply this model to Hanle spin precession measurements obtained on monolayer epitaxial graphene on SiC(0001). Combined with newly performed measurements on quasi-free-standing monolayer epitaxial graphene on SiC(0001) our analysis shows that the different values for the diffusion coefficient measured in charge and spin transport measurements on monolayer epitaxial graphene on SiC(0001) and the high values for the spin relaxation time can be explained by the influence of localized states arising from the buffer layer at the interface between the graphene and the SiC surface.
ABSTRACT
We measure spin transport in high mobility suspended graphene (µ ≈ 10(5)cm(2)/(V s)), obtaining a (spin) diffusion coefficient of 0.1 m(2)/s and giving a lower bound on the spin relaxation time (τ(s) ≈ 150 ps) and spin relaxation length (λ(s) = 4.7 µm) for intrinsic graphene. We develop a theoretical model considering the different graphene regions of our devices that explains our experimental data.
ABSTRACT
For more than 2 years now it has been controversially debated whether awareness of hypoglycemia is reduced when type I diabetic patients are switched from porcine to human insulin. In order to address this question, we studied nine C-peptide negative diabetics (age 27.6 years, Broca index 106%, duration of diabetes 5.7 years, HbA1, 8.8%) in comparison with eight healthy volunteers (age 22.4 years, Broca index 104%). Following euglycemic monitoring overnight, a controlled hypoglycemia was induced by altering the algorithms of the Biostator. This was done in a double-blind, cross-over fashion using porcine or human insulin on 2 nonconsecutive days. There were no differences between the results obtained with respect to the time course of the study, blood glucose, amount of insulin infused, and concentration of venous free insulin achieved. Of the nine diabetics, eight were aware of hypoglycemia at a higher blood glucose level under porcine insulin. The first symptom of hypoglycemia was perceived at a mean blood glucose level of 61.1 +/- 5.4 mg/dl under porcine insulin and of 44.4 +/- 5.3 mg/dl under human insulin (P less than or equal to 0.05). Thirty symptoms were noted under porcine insulin exclusively or preferentially as opposed to only eight which were observed exclusively or preferentially under human insulin. The healthy volunteers evidenced fewer symptoms at lower blood glucose concentrations than the diabetics. The clear difference between human and porcine insulin could not unequivocally be reproduced in this group.(ABSTRACT TRUNCATED AT 250 WORDS)
