The signature of a double quantum-dot structure in the I-V characteristics of a complex system

We demonstrate that by carefully analyzing the temperature dependent characteristics of the I-V measurements for a given complex system it is possible to determine whether it is composed of a single, double or multiple quantum-dot structure. Our approach is based on the orthodox theory for a double-dot case and is capable of simulating I-V characteristics of systems with any resistance and capacitance values and for temperatures corresponding to thermal energies larger than the dot level spacing. We compare I-V characteristics of single-dot and double-dot systems and show that for a given measured I-V curve considering the possibility of a second dot is equivalent to decreasing the fit temperature. Thus, our method allows one to gain information about the structure of an experimental system based on an I-V measurement.Comment: 12 pages 7 figure

Surgical Treatment of Aortic Valve Papillary Fibroelastoma in Combination With Coronary Artery Bypass Grafting

Objective: To describe a rare case of surgical treatment of aortic valve papillary fibroelastoma in combination with coronary artery bypass grafting.   Clinical case: The patient was hospitalized with a suspected mass on the left coronary cusp of the aortic valve and complained of retrosternal pain that appeared during moderate exertion and brisk walking and went away with rest. The patient history revealed that these clinical manifestations began in February 2022 and were treated by coronary stenting. Since May 2022 the patient noticed symptoms of recurrent angina. Transthoracic echocardiogram dated June 14, 2022 revealed a 13 × 12 mm additional mobile mass on the left coronary cusp. On June 30, 2022 the patient had an open surgery: mass removal, coronary artery bypass grafting of the anterior descending artery, and coronary artery bypass grafting of the circumflex artery. During the aortic valve exploration, the mass was visualized on the left coronary cusp on the side of the left ventricle. The mass was removed by precision marginal excision.   Conclusions: To timely examine patients, refer them for surgical treatment, preserve and prolong their life, and improve its quality, clinical practitioners should know clinical manifestations and challenges in screening for aortic valve papillary fibroelastoma

АНЕСТЕЗИОЛОГИЧЕСКОЕ ОБЕСПЕЧЕНИЕ И ИНТЕНСИВНАЯ ТЕРАПИЯ В ПЕРИОПЕРАЦИОННОМ ПЕРИОДЕ У ПАЦИЕНТОВ С ЛЕГОЧНОЙ ГИПЕРТЕНЗИЕЙ, ВЫЗВАННОЙ ЗАБОЛЕВАНИЯМИ ЛЕВЫХ ОТДЕЛОВ СЕРДЦА

Nowadays, the term "pulmonary hypertension" (PH) means a pathophysiological condition that may involve multiple clinical conditions and complicate the majority of cardiovascular and respiratory diseases. Clinical classification identifies 5 groups of pulmonary hypertension. This review focuses on group 2 - pulmonary hypertension due to left heart disease (PH due to LHD). In the general structure it takes about 80%. In routine practice, the contribution of this pathology to main disease is often underestimated, which can lead to increased mortality. The purpose of the literature review is to systematize and provide anesthesiologists with information on modern approaches to the diagnosis and treatment of PH due to LHD. The review presents data of the epidemiology and pathogenesis of this condition, describes the key concepts of adequate anesthetic management and effective intensive treatment of pulmonary hypertension in patients with left heart diseases.В настоящее время под термином «легочная гипертензия» трактуют патофизиологическое состояние, которое может включать разнообразные клинические состояния и осложнять течение большинства сердечно-сосудистых заболеваний и заболеваний системы дыхания. Современная классификация выделяет пять типов легочной гипертензии. Данный обзор посвящен второй группе ‒ легочной гипертензии, ассоциированной с заболеваниями левых отделов сердца. В общей структуре на ее долю приходится около 80%. В рутинной практике вклад этого состояния в течение основного заболевания часто недооценивается, что может приводить к повышению летальности. Цель ‒ систематизация данных и предоставление анестезиологам-реаниматологам сведений о современных подходах к диагностике и лечению легочной гипертензии второй группы. В обзоре приведены данные об эпидемиологии и патогенезе данного состояния, дано описание ключевых подходов адекватного анестезиологического обеспечения и эффективной интенсивной терапии легочной гипертензии у пациентов с заболеваниями левых отделов сердца

Comparative phylogeography of parasitic Laelaps mites contribute new insights into the specialist-generalist variation hypothesis (SGVH)

BACKGROUND: The specialist-generalist variation hypothesis (SGVH) in parasites suggests that, due to patchiness in habitat (host availability), specialist species will show more subdivided population structure when compared to generalist species. In addition, since specialist species are more prone to local stochastic extinction events with their hosts, they will show lower levels of intraspecific genetic diversity when compared to more generalist. RESULTS: To test the wider applicability of the SGVH we compared 337 cytochrome oxidase I mitochondrial DNA and 268 nuclear tropomyosin DNA sequenced fragments derived from two co-distributed Laelaps mite species and compared the data to 294 COI mtDNA sequences derived from the respective hosts Rhabdomys dilectus, R. bechuanae, Mastomys coucha and M. natalensis. In support of the SGVH, the generalist L. muricola was characterized by a high mtDNA haplotypic diversity of 0.97 (±0.00) and a low level of population differentiation (mtDNA Fst= 0.56, p < 0.05; nuDNA Fst = 0.33, P < 0.05) while the specialist L. giganteus was overall characterized by a lower haplotypic diversity of 0.77 (±0.03) and comparatively higher levels of population differentiation (mtDNA Fst = 0.87, P < 0.05; nuDNA Fst = 0.48, P < 0.05). When the two specialist L. giganteus lineages, which occur on two different Rhabdomys species, are respectively compared to the generalist parasite, L. muricola, the SGVH is not fully supported. One of the specialist L. giganteus species occurring on R. dilectus shows similar low levels of population differentiation (mtDNA Fst= 0.53, P < 0. 05; nuDNA Fst= 0.12, P < 0.05) than that found for the generalist L. muricola. This finding can be correlated to differences in host dispersal: R. bechuanae populations are characterized by a differentiated mtDNA Fst of 0.79 (P < 0.05) while R. dilectus populations are less structured with a mtDNA Fst= 0.18 (P < 0.05). CONCLUSION: These findings suggest that in ectoparasites, host specificity and the vagility of the host are both important drivers for parasite dispersal. It is proposed that the SGHV hypothesis should also incorporate reference to host dispersal since in our case only the specialist species who occur on less mobile hosts showed more subdivided population structure when compared to generalist species

Hypothermic Aortic Arch Flush for Preservation during Exsanguination Cardiac Arrest of 15 Minutes in Dogs

BACKGROUND: Trauma victims rarely survive cardiac arrest from exsanguination. Survivors may suffer neurologic damage. Our hypothesis was that a hypothermic aortic arch flush of 500 mL of isotonic saline solution at 4 degrees C, compared with 24 degrees C (room temperature), administered at the start of prolonged exsanguination cardiac arrest (CA) would improve functional neurologic outcome in dogs. METHODS: Seventeen male hunting dogs were prepared under light N2O-halothane anesthesia. The animals were randomized into two groups: group I (n = 9) received 4 degrees C isotonic saline flush and group II (n = 6) received 24 degrees C flush. Two additional dogs received no flush. While spontaneously breathing, the dogs underwent normothermic (tympanic membrane temperature [Ttm] = 37.5 degrees C) exsanguination over 5 minutes to cardiac arrest, assured by electric induction of ventricular fibrillation. After 2 minutes of arrest, the flush was administered over 1 minute into the aortic arch by means of a 13 French balloon-tipped catheter inserted by means of the femoral artery. After 15 minutes of CA, resuscitation was with closed-chest cardiopulmonary bypass, return of shed blood, and defibrillation. For the first 12 hours after CA, core temperature was maintained at 34 degrees C. Mechanical ventilation was continued to 20 hours and intensive care to 72 hours, when final evaluation and perfusion-fixation killing for brain histologic damage scoring were performed. RESULTS: Three dogs in group I were excluded because of extracerebral complications. All 14 dogs that followed protocol survived. During CA, the Ttm decreased to 33.6 +/- 1.2 degrees C in group I and 35.9 +/- 0.4 degrees C in group II (p = 0.002). At 72 hours, in group I, all dogs achieved an overall performance category (OPC) of 1 (normal). In group II, 1 dog was OPC 2 (moderate disability), 3 dogs were OPC 3 (severe disability), and 2 dogs were OPC 4 (coma). Both dogs without flush were OPC 4. Neurologic deficit scores (NDS 0% = normal, 100% = brain death) were 1 +/- 1% in group I and 41 +/- 12% in group II (p \u3c 0.05). The two dogs without flush achieved an NDS of 47% and 59%. Total brain histologic damage scores were 35 +/- 28 in group I and 82 +/- 17 in group II (p \u3c 0.01); and 124 and 200 in the nonflushed dogs. CONCLUSION: At the start of 15 minutes of exsanguination cardiac arrest in dogs, hypothermic aortic arch flush allows resuscitation to survival with normal neurologic function and histologically almost clean brains