Reversal mechanism of an individual Ni nanotube simultaneously studied by torque and SQUID magnetometry.

Using an optimally coupled nanometer-scale SQUID, we measure the magnetic flux originating from an individual ferromagnetic Ni nanotube attached to a Si cantilever. At the same time, we detect the nanotube's volume magnetization using torque magnetometry. We observe both the predicted reversible and irreversible reversal processes. A detailed comparison with micromagnetic simulations suggests that vortexlike states are formed in different segments of the individual nanotube. Such stray-field free states are interesting for memory applications and noninvasive sensing.

Single-charge transistor based on the charge-phase duality of a superconducting nanowire circuit.

We propose a transistorlike circuit including two serially connected segments of a narrow superconducting nanowire joint by a wider segment with a capacitively coupled gate in between. This circuit is made of amorphous NbSi film and embedded in a network of on-chip Cr microresistors ensuring a sufficiently high external electromagnetic impedance. Assuming a virtual regime of quantum phase slips (QPS) in two narrow segments of the wire, leading to quantum interference of voltages on these segments, this circuit is dual to the dc SQUID. Our samples demonstrated appreciable Coulomb blockade voltage (analog of critical current of the SQUIDs) and periodic modulation of this blockade by an electrostatic gate (analog of flux modulation in the SQUIDs). The model of this QPS transistor is discussed.

Quantum dynamics in a camelback potential of a dc SQUID.

We investigate a quadratic-quartic anharmonic oscillator formed by a potential well between two potential barriers. We realize this novel potential with a dc SQUID at near-zero current bias and flux bias near half a flux quantum. Escape out of the central well can occur via tunneling through either of the two barriers. We find good agreement with a generalized double-path macroscopic quantum tunneling theory. We also demonstrate an "optimal line" in current and flux bias along which the oscillator, which can be operated as a phase qubit, is insensitive to decoherence due to low-frequency current fluctuations.

Bloch inductance in small-capacitance Josephson junctions.

We show that the electrical impedance of a small-capacitance Josephson junction also includes, in addition to the capacitive term -i/(omega)CB, an inductive term i(omega)LB. Similar to the known Bloch capacitance CB(q), the Bloch inductance LB(q) also depends periodically on the quasicharge, q, and its maximum value achieved at q=e(mod 2e) always exceeds the value of the Josephson inductance of this junction LJ(phi) at fixed phi=0. The effect of the Bloch inductance on the dynamics of a single junction and a one-dimensional array is described.

[The role of an objective assessment of the heart right vientricle function for the anesthesiological maintenance and intensive therapy of surgical patients].

Latent dysfunction of the heart right ventricle and hypovolemia were assessed in 50 patients divided into 4 groups, operated on the heart, abdominal aorta and lungs. It was found that after revascularization of the myocardium the diastolic disorders prevailed. In patients operated for the heart valve (mitral and aortal) diseases prevailing were the systolic and pump dysfunction of the right ventricle. Insufficiency of the right ventricle in these groups was 13% and 22% respectively. After operations on the abdominal aorta a combination of the systolic and diastolic impairments of the right ventricle were observed. After extended resections of the lungs there was a characteristic combination of systolic, diastolic and pump dysfunctions. When the operation was followed by a decreased minute volume of circulation, its cause was hypovolemia in 29% of cases in the examined surgical patients. The investigation of the right ventricle functions with the help of pulmonary arterial volumetry can reveal their latent dysfunctions as well as hypovolemia in a considerable part of surgical patients.

Cooper pair cotunneling in single charge transistors with dissipative electromagnetic environment.

We observed current-voltage characteristics of superconducting single charge transistors with on-chip resistors of R approximately R(Q)=h/4e(2) approximately 6.45 kOmega, which are explained in terms of Cooper pair cotunneling. Both the effective strength of Josephson coupling and the cotunneling current are modulated by the gate-induced charge on the transistor island. For increasing values of the resistance R we found the Cooper pair current at small transport voltages to be dramatically suppressed.

Radio-frequency Bloch-transistor electrometer.

A quantum electrometer is proposed which is based on charge modulation of the Josephson supercurrent in the Bloch transistor inserted in a superconducting ring. As this ring is inductively coupled to a high- Q resonance tank circuit, the variations of the charge on the transistor island are converted into variations of amplitude and phase of oscillations in the tank. These variations are amplified and then detected. At sufficiently low temperature of the tank the device sensitivity is determined by the energy resolution of the amplifier, that can be reduced down to the standard quantum limit of 1 / 2Planck's over 2pi. A "back-action-evading" scheme of subquantum limit measurements is proposed.

[Infusion-transfusion therapy in chest wounds at medical evacuation stages]. / Infuzionno-transfuzionnaia terapiia pri raneniiakh grudi na étapakh meditsinskoi évakuatsii.

On the basis of the analysis of medical publications and practical experience in surgical care to the wounded the article discusses the tactics of infusion and transfusion therapy that should be used at the stages of medical evacuation. The authors emphasize the importance of the infusion therapy nearness to the place of accident, the necessity to provide medical personnel with adequate facilities for this task, careful attitude for autologous blood of wounded, blood reinfusion during pleural puncture or thoracotomy [correction of teracotomia]. The schemes of infusion and transfusion therapy for each stage of medical evacuation are enclosed.

[The surgical correction of an ostium secundum defect in the interatrial septum]. / Khirurgichna korektsiia na vtorichen defekt na mezhdupredsurdnata pregrada.

The operation of choice for correction of secundum type atrial septal defect is cardiopulmonary bypass. Combination of atrial septal defect with partial anomalous pulmonary venous drainage is considered absolute indication for bypass operation. The authors apply an original method for closure of the defect without resorting to bypass. For a period of seven years they have operated 240 patients from 3 to 54 years of age. Eighty four patients have been operated by the covered method of professor Zorin and in 23 correction of venous sinus defect was performed.

[Use of original valve devices on a catheter in the correction of aortic valve insufficiency (results of testing unit studies]. / Primenenie original'nykh klapannykh ustroistv na katetere dlia korrektsii nedostatochnosti aortal'nogo klapana (rezul'taty stendovykh ispytanii).

A defective aortic valve removed from a cadaver was installed on a testing unit imitating systemic circulation. The defect (insufficiency of the valve) was corrected by means of valvular devices consisting of a thin elastic membrane which was flat and round in one case and shaped like a spherical vault in the other; the devices were fastened on the distal end of a catheter. The authors present the values of pressure in the heart, aorta and coronary arteries and the minute circulation volume before and after correction of the defect. It is concluded that the suggested valvular devices are efficient and further study is expedient.

[Ion-balanced cardioplegic solutions in cardiac surgery]. / Ionosbalansovannye kardioplegicheskie rastvory v khirurgii serdtsa.

A comparative analysis of effectiveness of anti-ischemic defense of the myocardium performed in operations on the heart in 128 patients has shown that use of ion-balanced solutions is preferential since it allows reducing intrahospital lethality related with acute cardiac insufficiency from 13.3% to 6.3%.

[Remote results of the surgical treatment of aortic coarctation by the indirect isthmoplasty method]. / Otdalennye rezul'taty khirurgicheskogo lecheniia koarktatsii aorty metodom nepriamoi istmoplastiki.

Indirect isthmoplasty of the narrow portion of the aorta was performed in 79 patients. Immediate and nearest results have shown the effectiveness of the method in most patients. Remote results were studied in 55 patients, in 47 of them (85%) within the period of from 11 to 23 years after the operation. Unsatisfactory results were found in 28 patients (53%). In 18 patients (34%) the failure was caused by formation of an aneurysm in the site of plasty of the aorta with a synthetic flap. The frequency of the complication was found to depend on the term after surgery. In most cases (14) the aneurysms were formed because of disintegration of the suture material.