Crowdsourced knowledge catalyzes software development (Extended abstract)

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Four-dimensional ultrafast electron microscopy of phase transitions

Reported here is direct imaging (and diffraction) by using 4D ultrafast electron microscopy (UEM) with combined spatial and temporal resolutions. In the first phase of UEM, it was possible to obtain snapshot images by using timed, single-electron packets; each packet is free of space–charge effects. Here, we demonstrate the ability to obtain sequences of snapshots ("movies") with atomic-scale spatial resolution and ultrashort temporal resolution. Specifically, it is shown that ultrafast metal–insulator phase transitions can be studied with these achieved spatial and temporal resolutions. The diffraction (atomic scale) and images (nanometer scale) we obtained manifest the structural phase transition with its characteristic hysteresis, and the time scale involved (100 fs) is now studied by directly monitoring coordinates of the atoms themselves

The anatomy of a horizontally impacted maxillary wisdom tooth

A completely horizontally impacted upper third molar was revealed after routine dissection of a 62-year-old human cadaver of a Caucasian male. The molar was penetrating into the maxillary sinus and there was antral dehiscence of its bony alveolus. The bony alveolus was immediately in front of the greater palatine canal contents, and the bottom of the alveolus was dehiscent towards the greater palatine foramen. Within the greater palatine canal and foramen the greater palatine artery was duplicated and the nerve was found. Such antral relations of an impacted upper third molar predispose to oroantral communications if extraction is performed, while the close neurovascular relations represent a risk factor for postextractional haemorrhage and neurosensory disturbances and must be borne in mind when deciding on or performing the extraction. (Folia Morphol 2008: 67: 154–156

Scattering of slow-light gap solitons with charges in a two-level medium

The Maxwell-Bloch system describes a quantum two-level medium interacting with a classical electromagnetic field by mediation of the the population density. This population density variation is a purely quantum effect which is actually at the very origin of nonlinearity. The resulting nonlinear coupling possesses particularly interesting consequences at the resonance (when the frequency of the excitation is close to the transition frequency of the two-level medium) as e.g. slow-light gap solitons that result from the nonlinear instability of the evanescent wave at the boundary. As nonlinearity couples the different polarizations of the electromagnetic field, the slow-light gap soliton is shown to experience effective scattering whith charges in the medium, allowing it for instance to be trapped or reflected. This scattering process is understood qualitatively as being governed by a nonlinear Schroedinger model in an external potential related to the charges (the electrostatic permanent background component of the field).Comment: RevTex, 14 pages with 5 figures, to appear in J. Phys. A: Math. Theo

Design of a nitrogen-implanted titanium-based superelastic alloy with optimized properties for biomedical applications

International audienceIn this study, a superelastic Ni-free Ti-based biomedical alloy was treated in surface by the implantation of nitrogen ions for the first time. The N-implanted surface was characterized by X-ray diffraction, X-ray photoelectron spectroscopy, and secondary ion mass spectroscopy, and the superficial mechanical properties were evaluated by nano-indentation and by ball-on-disk tribological tests. To investigate the biocompatibility, the corrosion resistance of the N-implanted Ti alloy was evaluated in simulated body fluids (SBF) complemented by in-vitro cytocompatibility tests on human fetal osteoblasts. After implantation, surface analysis methods revealed the formation of a titanium-based nitride on the substrate surface. Consequently, an increase in superficial hardness and a significant reduction of friction coefficient were observed compared to the non-implanted sample. Also, a better corrosion resistance and a significant decrease in ion release rates have been obtained. Cell culture experiments indicated that the cytocompatibility of the N-implanted Ti alloy was superior to that of the corresponding non-treated sample. Thus, this new functional N-implanted titanium-based superelastic alloy presents the optimized properties that are required for various medical devices: superelasticity, high superficial mechanical properties, high corrosion resistance and excellent cytocompatibility

Retrosternal goiters

Clinica 1 Chirurgie, Clinica de Endocrinologie, Spitalul „Sf.Spiridon”, UMF ”Gr.T.Popa”, Iaşi, România, Al XII-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova cu participare internațională 23-25 septembrie 2015Introducere: Noțiunea de guşă retrosternală sau substernală reprezintă coborîrea a mai mult de 50% de glanda tiroidă în cavitatea toracică. Material şi metode: A fost efectuat un studiu retrospectiv a cazurilor de guşă retrosternală sau substernală din totalul de 2482 pacienți ce au suportat tiroidectomie în Clinica 1 Chirurgie din Iaşi în perioada 2000-2010. Guşa retrosternală a fost depistată la 54 (2,17%) pacienți. Toți bolnavii au fost îndreptați la operație din Clinica de Endocrinologie. Rezultate: Vîrsta medie a pacienților la momentul instalării diagnosticului a constituit 55,3±3,58 ani, majoritatea fiind femei – 83,3%. În manifestările clinice ale guşei retrosternale au dominat fenomenele de compresie. Dereglările funcției glandei tiroide au fost determinate prin teste hormonale efectuate în Clinica de Endocrinologie în 15 (27,7%) cazuri. Diagnoza de guşă retrosternală a fost suspectată în baza examenului clinic şi confirmată imagistic: radiografie toracică, ultrasonografie, computer tomografie. Abordul cervical a fost utilizat cu siguranță, sternotomia fiind necesară doar în 8 (14,8%) cazuri. Morbiditatea postoperatorie a constituit 5,5% (3 cazuri) cu mortalitate nulă. Durata medie de spitalizare a fost 4,3 zile. Noi am comparat datele noastre recente cu raportul privind tratamentul guşei retrosternale şi toracice în Clinica 1 Chirurgie din Iaşi în perioada anilor 1950-1979, publicat în revista „Chirurgia” în 1981. Concluzii: Guşa retrosternală reprezintă o formă specifică de patologie a glandei tiroide cu o incidență scăzută. Diagnosticul şi tratamentul guşei retrosternale implică o abordare multidisciplinară. Medicul endocrinolog are un rol important în diagnosticul şi supravegherea postoperatorie. Deşi intervenția chirurgicală este o metoda curativă de elecție pentru guşa substernală, persistă controverse privind abordul chirurgical şi rata complicațiilor. Abordul cervical poate fi utilizat cu siguranță aproape în toate cazurile, sternotomia fiind efectuată fără ezitare în caz de necesitate.Introduction: The term of retrosternal or substernal goiter means that more than 50% of thyroid gland descends in the thorax. Material and methods: There is a retrospective study on retrosternal and substernal goiter and its pathological features among 2482 patients who underwent thyroidectomy between 2000 and 2010 in the First Surgery Clinic of Iasi. Retrosternal goiter was diagnosed in 54 (2.17%) patients. All patients were referred to surgery from the Clinic of Endocrinology. Results: Mean age at diagnosis was 55.3±3.58 years, and most cases were found in women – 83.3%). The clinical picture of retrosternal goiter was dominated by compressive disorders. Thyroid function abnormalities were identified by hormonal assays performed on Endocrinology Clinic Iasi in 15 (27.7%) cases. The diagnosis of retrosternal goiter was suggested by clinical examination and confirmed by imaging: chest X-ray, ultrasound, CT scan. The cervical approach was safely performed. Only in 8 cases (14.8%), sternotomy was necessary. There was no mortality, and morbidity was 5.5% (3 cases). The length of stay in the hospital was 4.3 days. We compared our recent data with a previous report on retrosternal and thoracic goiter treated in First Surgery Clinic of Iasi during 1950 to 1979 and published in the journal “Chirurgia” in 1981. Conclusions: Retrosternal goiter is a particular form of thyroid surgical pathology presented with reduced incidence. Diagnosis and treatment of retrosternal goiter involve a multidisciplinary team. The endocrinologist has an important role in diagnosis and postoperative follow-up. Surgery is the treatment of choice for substernal goiters, but there are still some controversies on surgical approach, and complication rate. The cervical approach can be safely performed in almost all cases but when required, sternotomy should be performed without hesitation

Accelerating progress of Milenium Development Goals 6 on HIV/AIDS in the Republic of Moldova

The Government is committed to maintaining good public health services, so combatting the socially-conditioned diseases, such as HIV/AIDS, remains a priority. Despite the Government’s commitments and effort that has been made in collaboration with the development partners, the incidence of HIV has risen. In 2011, in order to accelerate the sustainable progress of HIV/AIDS, the Governments and relevant stakeholders decided to apply the Development Goals of Millennium Acceleration Framework (MAF), the methodology endorsed by the United Nations Development Group. With the support from UNDP, WHO and other UN institutions, the application of the MAF has helped investigate the social and medical determinants of health and identify the potential barriers within and outside the health system – bottlenecks at socio-economic and institutional levels. MAF is also focused on the needs of socially vulnerable groups of people that bear the brunt of HIV epidemics. Economic and social marginalization, stigmatization and discrimination they face are the underlying reasons of their vulnerability to these diseases

Translation Representations and Scattering By Two Intervals

Studying unitary one-parameter groups in Hilbert space (U(t),H), we show that a model for obstacle scattering can be built, up to unitary equivalence, with the use of translation representations for L2-functions in the complement of two finite and disjoint intervals. The model encompasses a family of systems (U (t), H). For each, we obtain a detailed spectral representation, and we compute the scattering operator, and scattering matrix. We illustrate our results in the Lax-Phillips model where (U (t), H) represents an acoustic wave equation in an exterior domain; and in quantum tunneling for dynamics of quantum states

Radiation damage in the LHCb vertex locator

The LHCb Vertex Locator (VELO) is a silicon strip detector designed to reconstruct charged particle trajectories and vertices produced at the LHCb interaction region. During the first two years of data collection, the 84 VELO sensors have been exposed to a range of fluences up to a maximum value of approximately 45 × 1012 1 MeV neutron equivalent (1 MeV neq). At the operational sensor temperature of approximately −7 °C, the average rate of sensor current increase is 18 μA per fb−1, in excellent agreement with predictions. The silicon effective bandgap has been determined using current versus temperature scan data after irradiation, with an average value of Eg = 1.16±0.03±0.04 eV obtained. The first observation of n+-on-n sensor type inversion at the LHC has been made, occurring at a fluence of around 15 × 1012 of 1 MeV neq. The only n+-on-p sensors in use at the LHC have also been studied. With an initial fluence of approximately 3 × 1012 1 MeV neq, a decrease in the Effective Depletion Voltage (EDV) of around 25 V is observed. Following this initial decrease, the EDV increases at a comparable rate to the type inverted n+-on-n type sensors, with rates of (1.43±0.16) × 10−12 V/ 1 MeV neq and (1.35±0.25) × 10−12 V/ 1 MeV neq measured for n+-on-p and n+-on-n type sensors, respectively. A reduction in the charge collection efficiency due to an unexpected effect involving the second metal layer readout lines is observed