321 research outputs found

    Original Article

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    Part I. Digitalis Ecg. in Goldberger\u27s Augmented Unipolar Limb Leads and Wilson\u27s Unipolar Chest Leads. There were analyzed the electrocardiograms of selected 37 cases which were scrupulously observed under the digitalis therapy on account of cardiac insufficiency. 1. P. a) Goldberger\u27s leads: The changes of P are generally not striking, only 2 cases showed the significant transformation in aV_R and aV_L, respectively. b) Wilson\u27s chest leads: The changes of P in V_1〜V_6 were found only in 4 cases. 2. Cardiac position and rotation. a) Goldberger\u27s leads: No more than 2 cases gave the disjtinct changes of the cardiac position in aV leads. b) At the early stage of digitalization the clockwise rotation was more frequently seen than the anticlockwise one. 3. ST. a) Goldberger\u27s leads: ST in aV_R were tend upward and ST in aV_F downward. ST in aV_L was either raised or lowered according to the cardiac position, but these changes were for the most part within normal limits. b) Wilson\u27s chest leads: Except for the extreme right ventricular strain curve, the digitalis ST depression was markedly observed in those leads which showed the largest upward deflection of QRS. Digitalis depresses ST of the levogram, and elevates ST of the dextrogram. However both in the excessive right ventricular strain curve and in the case with vivid Halb-seiten Effekt, digitalis does not raise ST of the dextrogram. 4. T. a) Goldberger\u27s leads: T in aV_F relatively often decreases in its positivity, becomes negative, and increases in its negativity. The characteristic changes due to digitalization are not clearly recognized in aV_R and aV_L. b) Wilson\u27s chest leads: T frequently decreases in its positivity, becomes negative or diphasic, and increases in its negativity. These changes are in special measure repeatedly found in the levogram. 5. Under the digitalization ventricular premature beats, auricular flutter and fibrillation appeared in several cases. Ventricular bigeminy and atrioventricular block were observed in each of two cases.On the contrary, there were found some cases in which the digitalization extinguished ventricular extrasystoles or bigeminy and auricular fibrillation persisted so long. Even in the presence of the ventricular bigeminy which is as a rule considered to be the indication to stop the digitalis use, yet digitalis can be administered under the closed notice. 6. Among 25 cases which showed sinus full rhythm, the prolongation of PR complicated with ST depression was observed in 6 cases (24 %). 7. Among 36 cases in which QT was estimated satisfactorily, the shortening of QT was found in 17 cases (47 %); 59 % of cases with shortened QT were accompanied by ST depression. 8. The digitalis bradycardia was recognized in 18 cases (49 %) and 65 % of bradycardic cases showed ST depression. 9. In the electrocardiograms of 7 cases suffered from the side effects of digitalis, i. e. vomitting, visual disturbance and so on, there could be often found arrhythmia and distinguished ST depression. The outburst of clinical side, effects was preceded by the clear-cut ST depression in two cases, so that it may possibly be taken the onset of the remarkable ST depression granted for an alarming sign of the threatening side effects. 10. The characteristic patterns of digitalis ecg. can be recognized even in the cases with digitalis refractoriness, the extent of such changes is, however, generally less striking and becomes as slighter as near death. Part II. Experimental Studies on so-called Digitalis Ecg. The experiments were carried on the dog\u27s hearts which were relatively resistive against digitalis Cdorsal fixation, isomytal anesthesia). a) the drip infusion of 1.0 mg of Strophosid intravenously. b) 5 times of the intravenous injections of 0.25 mg of Strophosid every 20 minutes. c) 3 times of the intravenous injection of 0.6 mg of Digicorin (AD-1), in total 1.8 mg. d) the intravenous injection of 1.0 mg of Acetylcholine before and after 1.8 mg of Digicorin.e) 2 times of the intravenous injection of 0.25 mg of Strophosid after the injection of 3.6 mg of Digicorin intravenously. f) the intravenous injection of 300 mg of Pronestyl at the event ventricular tachycardia due to over dosage of digitalis. The timepoint of every observation after the various digitalis injections is always the same; at each observation, besides registration of ecg., blood pressure and respiration, Wezler\u27s analysis was performed. 1) Either Strophosid or Digicorin, which is the limit of calculated therapeutic dosage, do not bring ST-T depression, whereas the calculated toxic doses of two drugs lower ST-T distinctly. There are found some cases in which the extrasystoles are preceded by the appearance of ST-T depression; therefore it cannot be concluded that changes of ST-T pattern can be possible for guide of the digitalis bioassay. 2) In the cases injected with Strophosid fractionatedly, ST-T depression can be recognized earlier at the smaller dosis than that in the cases treated by the drip intravenous infusion. Undiluted Strophosid does often elevate the blood pressure, chiefly due to increase in output. 3) The negative chronotropic action of both Strophosid and Digicorin is more or less weak. 4) The stimulation immediately after the cervical vago-sympathectomy prolongs PR, moreover occasionally elicits atrioventricular dissociation. 5) Even in the toxic stage of Strophosid the essential pattern of carotid sinus pressor reflex can be observed, although the degree \u27of reflexibility becomes smaller than that before the injection, and the reflex tachycardia becomes more vague. From these results it may be safe to say that the effect of reflexly augmented sympathicotonia by means of Hering\u27s second stimulation is difficult to take place because of the inhibitory vagal action of Strophosid. 6) The intravenous injection, of 1.0 mg of Acetylcholine administered before the use of Digicorin lowers the blood pressure range abruptly, and there develops apnea instantly after temporal hyperpnea.Electrocardiographically after ventricular arrest due to atrioventricular block followed tachycardic auricular impure flutter, there occured initially bradicardic, thereafter tachycardic auricular fibrillation, sinus complete rhythm, temporal atrioventricular dissociation in turn untill the complete sinus rhythm was recovered. The tachycardia which breaks out at the beginning, is considered to depend upon sinocarotid or cardioaortic chemoreceptor reflex, whereas the intravenous injection of 1.0 mg of Acetylcholine after Digicorin does not cause such an initial tachycardia, so that it may be appropriate to say that Digicorin does exert influence upon these reflex arcs. 7) The intravenous injection of Acetylcholine after application of Digicorin reveals quite the same extent of the reactivity with merely one half dosis, therefore it may be concluded that Digicorin is sure to promote the vagal tonisity. 8) The intravenous injection of Acetylcholine after the administration of Tropin brings out the inverse reaction of blood pressure, whereas the hyperventilation of short duration appears. The former phenomenon may be concerned with suppression of muscarinlike action of Acetylcholine, the latter with the deficiency of the paralytic action against visceroafferent fibre. 9) After the saturation accomplished with Digicorin the intravenous injection of Strophosid depresses ST-T and further there occurs ventricular tachycardia. Even after the saturation of Digicorin, of which toxity is very slight, the injection of Strophosid proves dangerous. 10) After the, saturation by the application of Digicorin, the ventricular tachycardia due to the intravenous injection of Strophosid cannot be prevented with the administration of 300 mg of pronestyl intravenously, so the arterial depression develops. But there appeared the reduction of QRS interval which can be thought to be improvement of intraventricular conduction disturbance; therefore in such event Pronestyl proves necessary.11) All instances injected with Strophosid as above mentioned may show subendocardial haemorrhage which was observed more markedly in the outflow area beneath aortic valves than in the inflow area under mitral valves. The subendocardial haemorrhage lacked in inflammation histologically. The cases treated with the singular use of Digicorin do not show the subendocardial haemorrhage even if ST-T depressed remarkably

    A Novel Non-interactive Deniable Authentication Protocol with Designated Verifier on elliptic curve cryptosystem

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    Recently, many non-interactive deniable authentication (NIDA) protocols have been proposed. They are mainly composed of two types, signature-based and shared-secrecy based. After reviewing these schemes, we found that the signature-based approach can not deny the source of the message and thus can not achieve full deniability; and that, the shared-secrecy based approach suffers KCI attack although it can achieve full deniability. In addition, both types of schemes lack efficiency consideration for they mainly base on DLP, factoring, or bilinear pairing. Due to this observation, in this paper, we use the Fiat-Shamir heuristic method to propose a new ECC-based NIDA protocol which not only can achieve full deniability but also is more efficient than all of the proposed schemes due to the inheritent property of elliptic curve cryptosystem. Further, we prove the properties of full deniability and KCI resistance conflict for a NIDA protocol. Besides, we deduce that a NIDA protocol is deniable if and only if it is perfect zero-knowledge

    Comparative transcriptomics of multidrug-resistant Acinetobacter baumannii in response to antibiotic treatments

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    Abstract Multidrug-resistant Acinetobacter baumannii, a major hospital-acquired pathogen, is a serious health threat and poses a great challenge to healthcare providers. Although there have been many genomic studies on the evolution and antibiotic resistance of this species, there have been very limited transcriptome studies on its responses to antibiotics. We conducted a comparative transcriptomic study on 12 strains with different growth rates and antibiotic resistance profiles, including 3 fast-growing pan-drug-resistant strains, under separate treatment with 3 antibiotics, namely amikacin, imipenem, and meropenem. We performed deep sequencing using a strand-specific RNA-sequencing protocol, and used de novo transcriptome assembly to analyze gene expression in the form of polycistronic transcripts. Our results indicated that genes associated with transposable elements generally showed higher levels of expression under antibiotic-treated conditions, and many of these transposon-associated genes have previously been linked to drug resistance. Using co-expressed transposon genes as markers, we further identified and experimentally validated two novel genes of which overexpression conferred significant increases in amikacin resistance. To the best of our knowledge, this study represents the first comparative transcriptomic analysis of multidrug-resistant A. baumannii under different antibiotic treatments, and revealed a new relationship between transposons and antibiotic resistance

    First-order magnetic and structural phase transitions in Fe1+y_{1+y}Sex_xTe1x_{1-x}

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    We use bulk magnetic susceptibility, electronic specific heat, and neutron scattering to study structural and magnetic phase transitions in Fe1+y_{1+y}Se% x_xTe1x_{1-x}. Fe1.068_{1.068}Te exhibits a first order phase transition near 67 K with a tetragonal to monoclinic structural transition and simultaneously develops a collinear antiferromagnetic (AF) order responsible for the entropy change across the transition. Systematic studies of FeSe%_{1-x}Tex_x system reveal that the AF structure and lattice distortion in these materials are different from those of FeAs-based pnictides. These results call into question the conclusions of present density functional calculations, where FeSe1x_{1-x}Tex_x and FeAs-based pnictides are expected to have similar Fermi surfaces and therefore the same spin-density-wave AF order.Comment: 5 pages, 3 figure

    An efficient RFID mutual authentication scheme based on ECC

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    Recently, Radio Frequency Identification (RFID) technique has been widely deployed in many applications, such as medical drugs management in hospitals and missing children searching in amusement parks. The applications basically can be classified into two types: non-public key cryptosystem (PKC)-based and PKC-based. However, many of them have been found to be flawed in the aspect of privacy problem. Therefore, many researchers tried to resolve this problem. They mainly investigated on how low-cost RFID tags can be used in large-scale systems. However, after analyses, we found those studies have some problems, such as suffering physical attack or de-synch attack. Hence, in this paper, we try to design an efficient RFID scheme based on Elliptic Curve Cryptography (ECC) to avoid these problems. After analyses, we conclude that our scheme not only can resist various kinds of attacks but also outperforms the other ECC based RFID schemes in security requirements, with needing only little extra elliptic curve point multiplications

    Ventricular divergence correlates with epicardial wavebreaks and predicts ventricular arrhythmia in isolated rabbit hearts during therapeutic hypothermia

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    INTRODUCTION: High beat-to-beat morphological variation (divergence) on the ventricular electrogram during programmed ventricular stimulation (PVS) is associated with increased risk of ventricular fibrillation (VF), with unclear mechanisms. We hypothesized that ventricular divergence is associated with epicardial wavebreaks during PVS, and that it predicts VF occurrence. METHOD AND RESULTS: Langendorff-perfused rabbit hearts (n = 10) underwent 30-min therapeutic hypothermia (TH, 30°C), followed by a 20-min treatment with rotigaptide (300 nM), a gap junction modifier. VF inducibility was tested using burst ventricular pacing at the shortest pacing cycle length achieving 1:1 ventricular capture. Pseudo-ECG (p-ECG) and epicardial activation maps were simultaneously recorded for divergence and wavebreaks analysis, respectively. A total of 112 optical and p-ECG recordings (62 at TH, 50 at TH treated with rotigaptide) were analyzed. Adding rotigaptide reduced ventricular divergence, from 0.13±0.10 at TH to 0.09±0.07 (p = 0.018). Similarly, rotigaptide reduced the number of epicardial wavebreaks, from 0.59±0.73 at TH to 0.30±0.49 (p = 0.036). VF inducibility decreased, from 48±31% at TH to 22±32% after rotigaptide infusion (p = 0.032). Linear regression models showed that ventricular divergence correlated with epicardial wavebreaks during TH (p<0.001). CONCLUSION: Ventricular divergence correlated with, and might be predictive of epicardial wavebreaks during PVS at TH. Rotigaptide decreased both the ventricular divergence and epicardial wavebreaks, and reduced the probability of pacing-induced VF during TH

    A Novel RFID Authentication Protocol based on Elliptic Curve Cryptosystem

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    Recently, many researchers have proposed RFID authentication protocols. These protocols are mainly consists of two types: symmetric key based and asymmetric key based. The symmetric key based systems usually have some weaknesses such as suffering brute force, de-synchronization, impersonation, and tracing attacks. In addition, the asymmetric key based systems usually suffer from impersonation, man-in-the-middle, physical, and tracing attacks. To get rid of those weaknesses and reduce the system workload, we adopt elliptic curve cryptosystem (ECC) to construct an asymmetric key based RFID authentication system. Our scheme needs only two passes and can resist various kinds of attacks. It not only outperforms the other RFID schemes having the same security level but also is the most efficient

    Identifying Large-Scale RFID Tags Using Non-Cryptographic Approach

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    In this paper, we propose a new approach to identify a tag of a RFID system in constant time while keeping untraceability to the tag. Our scheme does not use any cryptographic primitives. Instead, we use a line in a plane to represent a tag. The points on the line, which are infinite and different each other, can be used as tag identification. We also explore the scalability of the proposed scheme. The result of experiments showed that a tag of the RFID system over 1,000,000 tags, embedded 3000 gates, can store 559 dynamic identity proofs
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