67 research outputs found

    Orbitally induced hierarchy of exchange interactions in zigzag antiferromagnetic state of honeycomb silver delafossite Ag3Co2SbO6

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    We report the revised crystal structure, static and dynamic magnetic properties of quasi-two dimensional honeycomb-lattice silver delafossite Ag3Co2SbO6. The magnetic susceptibility and specific heat data are consistent with the onset of antiferromagnetic long range order at low temperatures with N\'eel temperature TN ~ 21.2 K. In addition, the magnetization curves revealed a field-induced (spin-flop type) transition below TN in moderate magnetic fields. The GGA+U calculations show the importance of the orbital degrees of freedom, which maintain a hierarchy of exchange interaction in the system. The strongest antiferromagnetic exchange coupling was found in the shortest Co-Co pairs and is due to direct and superexchange interactions between the half-filled xz+yz orbitals pointing directly to each other. The other four out of six nearest neighbor exchanges within the cobalt hexagon are suppressed, since for these bonds active half-filled orbitals turned out to be parallel and do not overlap. The electron spin resonance (ESR) spectra reveal a Gaussian shape line attributed to Co2+ ion in octahedral coordination with average effective g-factor g=2.3+/-0.1 at room temperature and shows strong divergence of ESR parameters below 120 K, which imply an extended region of short-range correlations. Based on the results of magnetic and thermodynamic studies in applied fields, we propose the magnetic phase diagram for the new honeycomb-lattice delafossite

    Formation of an integrated financial regulation system of transport corporations’ economic development

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    Scientific findings of this article correspond with the fact that the development of interacting business entities is quite diverse. This affects the efficiency of corporations’ budget management. So, a need arises to adjust the financial assets applied to the development of integrated enterprises, basing on their economic compatibility evaluation. Authors suggest using the companies’ development intensity determined by the increasing qualitative business activity indicators compared to the increasing quantitative ones. Theoretical economics gives no clear definition of compatibility of developing companies. Economic practices do not pay proper attention to the development of effective financial regulation of economic development of companies integrated into a corporation. The article suggests original definitions of economic compatibility as well as the model of forming the integrated system of transport companies’ economic development on the basis of morphological approach. Theoretical and methodological findings are approved in the business activity of transport corporationspeer-reviewe

    The first rays joint fractures and treatment modalities

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    Catedra de ortopedie și traumatologie, USMF „Nicolae Testemițanu”, Clinica de chirurgie plastică și microchirurgie reconstructivă a locomotorului, IMSP IMU, Chișinău, Republica Moldova, Conferința stiințifică „Nicolae Anestiadi – nume etern al chirurgiei basarabene” consacrată centenarului de la nașterea profesorului Nicolae Anestiadi 26 august 2016Introducere. Incidenţa crescută a traumatismelor mâinii ocupa primul loc in traumatismele corpului uman. Aceasta stimulează în permanenţă ingeniozitatea chirurgilor în a găsi noi metode reconstructive tot mai performante. Deși, ei se confruntă pe de o parte, cu anatomia complexă a mâinii, iar pe de altă parte cu obligativitatea de a păstra integritatea sistemului nervos, vascular şi tendinos totuși, este reala posibilitatea unei reconstrucţii complexe cu ţesuturi similare fără a crea defecte secundare importante.Scopul. Eșalonarea incidenței lezionale a policelui în complexul de traumatisme ale mâinii si separarea itimilor depistați în funcție de suprafață și pe nivele razei digitale. Material si metode. În lucrare am inclus un lot de 460 de pacienți pe perioada anului 2015. Limitele de vârsta au fost între 19-70 ani, divizați pe categorii a câte 10 ani. Repartizarea pe sexe dintre cei 79 de pacienți cu traumatisme a policelui a constituit: 69 (87.34%) bărbați si 10 (12.66%) femei. Frecvența traumatismelor înregistrate la membrul stâng 40 (50.34%) a fost mai mare decât la membrul drept 39 (49.67%). 79 (17.17%) pacienți din lotul total au suferit traumatisme ale policelui, dintre care: separat al policelui 46 (58.22%) și în complex cu alte degete 33 (41.78%). În traumatismele policelui pe segmente au fost incluși pacienții tratați in staționar. Falanga proximală s-a dovedit a fi cel mai des traumată 39 (49.36%) de cazuri, apoi urmează falanga distală 37 (46.83%) de cazuri și doar în 3 (3.79%) cazuri au avut de suferit ambele falange. Rezultate. Incidența traumatismului policelui separat se întâlnesc la 46(58.22%) de pacienți și in complex cu alte degete la 33 (41.78%) de pacienți. Ceia ce constituie din ansamblu de traumatisme ale mâinii 17.17%. Prelucrarea materialului obținut denota prevalenta incidentei pentru falanga distală a policelui dar nu si ca gravitate care se manifesta mai accentuat pe măsura avansării spre baza lui. Aceasta a dictat managementul tratamentului si complexitatea intervențiilor chirurgicale efectuate. Concluzie. Leziunile policelui in complexul traumatismelor mâinii se întâlnesc mai des ca fiind un traumatism separat decât in asociere cu celelalte degete ale mâinii, prevalând la bărbați, iar membrul superior stâng fiind afectat intr-o incidenta ușor mai sporită.Introduction. The increased incidence of hand trauma injuries ranks first in the human body. This continually stimulates surgeons ingenuity to find new performant ways in reconstructive methods. Although, they are facing, on the one hand, with complex hand’s anatomy complex and, on the other hand, with the obligation to preserve the integrity of the nervous, vascular and tendon system, however, it is real the possibility of a complex reconstruction with similar tissues without creating significant defects. Purpose. Distribution of thumb’s lesional incidence in hand’s trauma complex and items separation detected depending on the surface and levels of digital beam. Material and methods. In this paper we included a group of 460 patients treated during the 2015 year. The age limits were between 19-70 years, divided into categories of 10 years. The sex ratio of the 79 patients with thumb injury was: 69 (87.34%) men and 10 (12.66%) women. Frequency of trauma registered in left member - 40 (50.34%), was higher than in the right one - 39 (49.67%). 79 (17.17%) patients from total group have suffered thumb’s trauma, including: separate thumb - 46 (58.22%) and in complex with other fingers - 33 (41.78%). In thumb’s trauma, according to segments, were included patients treated in hospital. Proximal phalanx was found to be most traumatized - 39 (49.36%) cases, followed by the distal phalanx - 37 (46.83%) cases and only in 3 (3.79%) cases have suffered both phalanges. Results. Incidents of separate thumb’s trauma are met at 46 (58.22%) patients and in complex with other fingers in 33 (41.78%) patients, which constitutes in the ensemble of hand’s trauma 17.17%. Processing of obtained material denotes prevalence of incidence of thumb’s distal phalanx, but not the severity that manifests more pronounced as it progresses toward its base. This dictated the treatment’s management and complexity of performed surgery. Conclusion. Thumb’s injuries in complex of hand’s trauma are more often met as a separate trauma than in association with other fingers of the hand, with prevalence in men, and left upper limb is affected with a slightly increased incidence

    Possibilities of heterologous use of the island flaps from the trunk

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    Clinica Chirurgie Plastică și Microchirurgie Reconstructivă, USMF “Nicolae Testemiţanu”, Chișinău, Republica Moldova, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Trunchiul dispune de o varietate mare de lambouri, care pot fi utilizate în reconstrucţia defectelor. Cunoaşterea tuturor tipurilor ale acestora permite lărgirea spectrului metodelor reconstructive. Scopul lucrării: Evidenţierea potenţialului donator al ţesuturilor de pe trunchi pentru plastii vascularizate a defectelor. Material și metode: În studiu au fost incluși 13 pacienţi care au suportat plastii cu lambouri vascularizate axial, recoltate de pe trunchi. Pacienţii trataţi, maturi cu vârste cuprinse între 45 – 76 ani, au constituit o pondere a bărbaţilor în raport cu sexul feminin – 11:2. Am explorat 3 zone donatoare de lambouri la nivelul trunchiului: lamboul mușchiului lat al spatelui (7), parascapularul (1) și lamboul inghinal (5). Lambourile utilizate au acoperit un defect în regiunea axilară; 5 defecte pe braţ și cot; 2 defecte pe torace; 4 defecte pe mână și un defect pe coapsă. Dimensiunile defectelor tratate au variat între 76 cm2 și 408 cm2. Rezultate: Tratamentul fiecărui pacient cu transfer de pe trunchi pe membre a sumat două intervenţii chirurgicale: prima – formarea lamboului și acoperirea defectului și a doua: la 17- 20 zile distanţă – disecţia pediculului nutritiv de la zona donatoare cu închiderea căilor de migrare. Această perioadă a fost marcată de incomodităţi pentru pacienţi, cauzate de poziţia forţată a membrului. Totuși, menţionăm că în toate cazurile am obţinut închiderea defectelor. Concluzii: Utilizarea lambourilor insulare de pe trunchi în acoperirea defectelor pe membre este o opţiune de rezervă, dar și salvatoare atunci când utilizarea altor tipuri de plastii este contraindicată.Introduction: The trunk benefits from multiple flaps that can be used in defects reconstruction. Knowing all types of them allows to enlarge the spectrum of reconstructive methods. Purpose of the study: To highlight donor tissue’s potential from trunk for vascularized plasties of defects. Material and methods: The study included 13 patients who underwent plasty with axial vascularized flaps harvested from trunk. Treated patients – adults, aged 45-74 years, males prevailed (M:F = 11:2). We explored 3 flap donor sites at tunk’s level: latissimus dorsi flap (7), parascapular (1) and inguinal flap (5). Used flap covered a defect in axilar region, 5 defects on arm and elbow, 2 defects on thorax, 4 defects on hand and 1 defect on thigh. The defects dimensions ranged between 76 and 408 cm2. Results: The treatment of each patient with transfer from trunk to limbs consisted of 2 interventions: first-flap’s formation and defect’s cover, and second – at 17-20 days away, nourishing pedicle’s dissection from donor site with closure of migration routes. This period was marked by patients’ inconveniences caused by limb’s forced position. However, we note that in all cases we achieved closure of defects. Conclusions: Use of island flaps from trunk for covering defects of limbs is a reserve option, but also saving when using other types of plasty is contraindicated

    Diagnostic value of the microsurgicaly transplanted tissues termometry

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    Clinica de Chirurgie Plastică și Microchirurgie Reconstructivă, USMF “Nicolae Testemiţanu”, Chișinău, Republica Moldova, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Perioada postoperatorie a transferurilor microchirurgicale este frecvent marcată de dereglări vasculare în ţesuturile transplantate (5-17%). Uneori complicaţiile agravează starea lor necesitînd intervenţia urgentă a medicului. Scopul: Evaluarea valorii diagnostice a termometrizării locale a ţesuturilor transplantate microchirurgical pentru depistarea precoce a tulburărilor vasculare acute. Material și metode: Termometrizarea s-a efectuat cu termometrul electronic, cu precizie de 0,1°C la un grup de 87 de bolnavi. Datele au fost înregistrate sub formă de curbe termice. Valorile termice ale segmentelor la nivelul cărora s-au migrat lambourile, au fost considerate drept valori de referinţă cu care s-au comparat valorile termice culese de pe lambouri. Diferenţele termice sau considerat negative cînd temperatura lamboului înregistra valori mai mici, nule – cînd temperaturile erau egale și pozitive cînd temperatura lamboului depășea temperatura segmentului operat. În perioada postoperatorie pînă la 15 zile termometria s-a efectuat zilnic. Datele au fost prelucrate statistic prin metoda “regresiei pas cu pas” cu coeficienţi veridici (r=0,49342; P=0,019). Rezultate: În perioada imediat postoperatorie (15–20 zile) valorile termice ale lambourilor sunt negative, cu temperaturi mai joase cu 1-2°C faţă de membrul operat. Diferenţele mai mari de 2°C indică asupra unor tulburări vasculare. Pentru perioada postoperatorie tardivă (reconvalescenţă) diferenţele erau sub 1°C și descreșteau, iar la 15 pacienţi erau egale. În două cazuri diferenţele depășeau 1°C. Concluzii: În perioada imediat postoperatorie majorarea diferenţei termice dintre ţesuturile transplantate și ţesuturile neafectate ale segmentului cu mai mult de 2 grade indică o catastrofă vasculară acută în lamboul transplantat, necesitînd măsuri de salvare. Pentru perioada de reconvalescenţă diferenţele de temperaturi mai mari de 1 grad indică asupra integrării incomplete a lamboului la situsul de recepţie.Introduction: Microsurgical transfers postoperative period is often marked by vascular disorders in transplanted tissues (5- 15%). Sometimes complications worsen their condition requiring urgent doctor’s intervention. Aim: Evaluation of local thermometry’s diagnostic value of microsurgical transplanted tissues for early detection of acute vascular disorders. Material and methods: Thermometry was done using electronic thermometer, with accuracy of 0.1°C in a group of 87 patients. Data were recorded in the form of thermic curves. Thermal values from segments at which were migrated flaps were considered benchmarks with whom we compared thermal values of flaps. Thermal differences were negative when flap’s temperature recorded lower values, null – when it was equal and positive – when it exceeded temperature of operated segment. Data were statistically processed using „step by step regression” method with veridic coefficients (r=0.49342; P=0.019). Results: In immediate postoperative period (15-20 days) flaps thermal values were negative, with temperature lower by 1-2°C than operated limb. Differences greater than 2°C indicate some vascular disorders. During late postoperative period differences were less than 1°C and decreased, and in 15 patients – were equal. In 2 cases differences exceeded 1°C. Conclusions: In immediate postoperative period increase in thermal difference between transplanted and unaffected tissues more than 2°C indicates acute vascular catastrophe, requiring rescue measures. In reconvalescence period thermal differences greater than 1°C indicate incomplete flap’s integration at recipient site

    Planning flaps in the calf according to availability physiology

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    Catedra de ortopedie și traumatologie, USMF „Nicolae Testemițanu”, Clinica de chirurgie plastică și microchirurgie reconstructivă a locomotorului, IMSP IMU, Chișinău, Republica Moldova, Conferința stiințifică „Nicolae Anestiadi – nume etern al chirurgiei basarabene” consacrată centenarului de la nașterea profesorului Nicolae Anestiadi 26 august 2016Introducere. Acest studiu a fost efectuat pentru a determina lățimea optima disponibila a zonei donatoare de lambou care nu va prejudicia închiderea primara a plăgii donore, fiind suturata primar plan cu plan.Scop. Evaluarea disponibilității tegumentare fiziologice a fiecărei regiuni donatoare de la nivelul gambei. Material și metode. Studiul a fost efectuat pe un lot de 30 de voluntari, pe membrele sănătoase. Limitele de vârsta in lot au fost de 20 - 60 de ani, divizate pe categorii a câte 10 ani, fiecare subcategorie incluzând minim 5 voluntari. Disponibilitatea fiziologica s-a calculat pentru lambourile: safen, sural, peronier superficial, suprameleolar, fibular, tibial posterior si tibial anterior. Tegumentul s-a plicaturat in centrul teritoriului donator (cetripet), pana când părtile plicaturate contactau formând duplicatura (Ld). Grosimea duplicaturii s-a măsurat, fiind trecuta pe linia milimetrica. Ulterior, plica cutanata era desfăcuta la parametrii normali ai tegumentului cu extensia acelorași puncte in exterior (centrifug), fixându-se lungimea in milimetri (Le). Disponibilitatea tegumentara fiziologica (Dt) s-a calculat după formula: Dt =Le – Ld. Rezultate. Cea mai mare disponibilitate fiziologica la nivelul gambei s-a determinat in regiunea lamboului safen (5.05±0.29 cm; n=30; p=0.033), urmata de regiunea lamboului sural (4.83±0.25 cm; n=30; p=0.028) si regiunea lamboului tibial anterior (4.28±0.20 cm; n=30; p=0.03). Cea mai mica disponibilitate fiziologica s-a determinat în regiunea lamboului supramaleolar (3.04±0.21 cm; n=30; p=0.018). Concluzii. În urma studiului efectuat am constatat ca ridicarea unui lambou cu lățimea disponibila fiziologica a regiunilor donatoare la gamba nu va produce probleme de închidere a plăgii donore, fiind suturata primar plan cu plan.Introduction. This study was conducted to determine the optimal, available width of the flap’s donor site that will not harm the primary closure of donor wound. Purpose. To assess the skin physiological availability of each donor region of the calf. Material and methods. The study was conducted on a group of 30 volunteers, assessing healthy limbs. Age limits in group were 20-60 years, divided into categories of 10 years, including at least 5 volunteers each category. Physiological availability was calculated for flaps: saphenous, sural, superficial peroneal, suprameleolar, fibular, posterior and anterior tibial. The skin was fold in the center of donor territory (centripetal) until the folded parts was contacting, forming a folding (Ld). Folding’s thickness was measured, being passed on millimeter line. Subsequently, skin fold was unfolded to normal skin with the extension of the same points outside (centrifugal), attaching the length in millimeters (Le). Skin physiological availability (Dt) was calculated using the formula: Dt = Le - Ld. Results. Highest physiological availability was determined in region of saphenous flap (5.05±0.29 cm; n = 30; p = 0.033), followed by the sural flap (4.83±0.25 cm; n=30; p= 0.028) and region of anterior tibial flap (4.28±0.20 cm, n=30; p=0.03). The smallest physiological availability was determined in the region of supramalleolar flap (3.04±0.21 cm, n = 30; p = 0.018). Conclusions. From this study we found that raising a flap with physiological available width of donor regions of calf will not cause problems in donor wound’s closure, this being sutured primary

    Typology of seismic motion and seismic engineering design

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    The paper deals with the influence of the seismic motion typology on the structural response and with engineering design under exceptional actions. Various aspects of seismic motion typology that lead to exceptional actions on the structures are covered. The influence of near fault ground motions, the effect of local site parameters and the magnification of the seismic action on short-period structures are among the parameters identified as dominant for the structural response. The paper presents also a methodology for handling uncertainty in engineering design, based on the mathematical framework of fuzzy analysis. Finally the paper presents various applications of performance based design, which is viewed as a tool as a tool for the analysis of structural behaviour under extreme seismic events. The influence of connection behaviour on the structural response is studied, and applications of the capacity design methodology and of the direct displacement design approach for the evaluation of reinforce concrete structures are presented

    Static and dynamic magnetic response of fragmented haldane-like spin chains in layered Li3Cu2SbO6

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    The structure and the magnetic properties of layered Li3Cu2SbO6 are investigated by powder X-ray diffraction, static susceptibility, and electron spin resonance studies up to 330 GHz. The XRD data experimentally verify the space group C2=m with halved unit cell volume in contrast to previously reported C2=c. In addition, the data show significant Li=Cuintersite exchange. Static magnetic susceptibility and ESR measurements show two magnetic contributions, i.e., quasifree spins at low-temperature and a spin-gapped magnetic subsystem, with about half of the spins being associated to each subsystem. The data suggest ferromagnetic-antiferromagnetic alternating chains with JFM = -285 K and JAFM = 160 K with a significant amount of Li-defects in the chains. The results are discussed in the scenario of fragmented 1D S = 1 AFM chains with a rather high defect concentration of about 17% and associated S =1=2 edge states of the resulting finite Haldane chains. © 2016 The Physical Society of Japan

    Steel-based applications in earthquake-prone areas

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    Steel-Earth project aims at distributing among technicians, engineers, design companies and standardization bodies the results of three past RFCS projects (Steel-Retro [3], Opus [2] and PrecaSteel [1]), providing useful tools for the design and for the retrofit of existing buildings. Technical documents and practical applications to case studies, regarding design of steel and composite steel/concrete buildings and innovative steel-based techniques for the retrofit of existing r.c. and masonry constructions, have been elaborated and collected into a volume distributed during the final workshop of the dissemination project. Pre-normative and background documents concerning the design of steel and composite structures and the rehabilitation of existing constructions have been prepared. A lot of attention has been paid to the analysis of the influence of overstrength factors on the seismic design of steel and composite structures. The prepared documents have been distributed to the attending people and to the members of WG 2 (CEN/TC 250/SC 8/WG 2 “Steel and Composite Structures”) during the final workshop of the project. Technical sheets, working examples and background documents have been translated into several languages (German, French, Italian, Romanian and Greek) and are free available on the website of the project (https://www.steelconstruct.com/site/), where information regarding Steel-Earth are also presented.11 Workshops in Italy, Greece, Germany, Belgium, Portugal, Spain and Romania and 5 conferences in Emilia-Romagna have been organized, as well as 2 practical courses for engineers and academic people in Pavia (Italy). Flash-drives with the technical documents and applications elaborated in Steel-Earth have been distributed to the attending people
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