Thermodynamic signatures of quantum criticality in cuprate superconductors.

The three central phenomena of cuprate (copper oxide) superconductors are linked by a common doping level p*-at which the enigmatic pseudogap phase ends and the resistivity exhibits an anomalous linear dependence on temperature, and around which the superconducting phase forms a dome-shaped area in the phase diagram1. However, the fundamental nature of p* remains unclear, in particular regarding whether it marks a true quantum phase transition. Here we measure the specific heat C of the cuprates Eu-LSCO and Nd-LSCO at low temperature in magnetic fields large enough to suppress superconductivity, over a wide doping range2 that includes p*. As a function of doping, we find that Cel/T is strongly peaked at p* (where Cel is the electronic contribution to C) and exhibits a log(1/T) dependence as temperature T tends to zero. These are the classic thermodynamic signatures of a quantum critical point3-5, as observed in heavy-fermion6 and iron-based7 superconductors at the point where their antiferromagnetic phase comes to an end. We conclude that the pseudogap phase of cuprates ends at a quantum critical point, the associated fluctuations of which are probably involved in d-wave pairing and the anomalous scattering of charge carriers.

Thrombus or tumor? A case report of a rare sarcoma entity: intimal sarcoma of the pulmonary arteries.

BACKGROUND: Tumor embolism is a very rare primary manifestation of cancers and the diagnosis is challenging, especially if located in the pulmonary arteries, where it can mimic nonmalignant pulmonary embolism. Intimal sarcoma is one of the least commonly reported primary tumors of vessels with only a few cases reported worldwide. A typical location of this malignancy is the pulmonary artery. Herein, we present a case report of an intimal sarcoma with primary manifestation in the pulmonary arteries. A 53-year-old male initially presented with dyspnea. On imaging, a pulmonary artery embolism was detected and was followed by thrombectomy of the right ventricular outflow tract, main pulmonary artery trunk, and right pulmonary artery after ineffective lysis therapy. Complementary imaging of the chest and abdomen including a PET-CT scan demonstrated no evidence of a primary tumor. Subsequent pathology assessment suggested an intimal sarcoma further confirmed by DNA methylation based molecular analysis. We initiated adjuvant chemotherapy with doxorubicin. Four months after the completion of adjuvant therapy a follow-up scan revealed a local recurrence without distant metastases. DISCUSSION: Primary pulmonary artery intimal sarcoma (PAS) is an exceedingly rare entity and pathological diagnosis remains challenging. Therefore, the detection of entity-specific molecular alterations is a supporting argument in the diagnostic spectrum. Complete surgical resection is the prognostically most important treatment for intimal cardiac sarcomas. Despite adjuvant chemotherapy, the prognosis of cardiac sarcomas remains very poor. This case of a PAS highlights the difficulty in establishing a diagnosis and the aggressive natural course of the disease. CONCLUSION: In case of atypical presentation of a pulmonary embolism, a tumor originating from the great vessels should be considered. Molecular pathology techniques support in establishing a reliable diagnosis.

Phosphocholine-binding antibody activities are hierarchically encoded in the sequence of the heavy-chain variable region: dominance of self-association activity in the T15 idiotype.

A methodology based on the representation of each amino acid of a protein sequence by the electron-ion interaction potential and subsequent analysis by signal processing was used to determine the characteristic or common frequency (in Hz) that reflects the biological activity shared among phosphocholine (PC)-binding antibodies. The common frequency for the variable portion of the heavy chain (VH) of the PC-specific antibodies is found to be at f = 0.37 Hz. The VH sequences of the PC-binding antibodies exhibit three subsites for the PC moiety where hypervariable region 2 (CDR2) plays a role in the interaction with the phosphate group. Mutations in this VH region have an impact on the ability of mutant variants to bind PC and its carrier molecule, as well as on the characteristic frequency shift toward f = 0.12 Hz for mutants failing to bind both hapten and carrier. The VH sequence of mutants that retain the ability to bind PC still shows f = 0.37 Hz, suggesting that this frequency determines PC binding. However, this statement was not confirmed as mutation in another PC subsite impairs PC binding but retains both the phosphate-group recognition and the frequency at f = 0.37 Hz. Herein, this finding is discussed to promote the idea that the VH sequence of the PC-binding antibodies encodes the subsite for phosphate-group binding as a dominant functional activity and that only CDR2 of the T15-idiotype antibodies together with FR3 region form an autonomous self-association function represented by the T15VH50-73 peptide with f = 0.37±0.05 Hz. Thus, these data confirmed that T15VH50-73 peptide might be used in superantibody technology.

Photoluminescence of atomic gold and silver particles in soda-lime silicate glasses.

We report the chemistry and photophysics of atomic gold and silver particles in inorganic glasses. By synchrotron irradiation of gold-doped soda-lime silicate glasses we could create and identify unambiguously the gold dimer as a stable and bright luminescing particle embedded in the glassy matrix. The gold dimer spectra coincide perfectly with rare gas matrix spectra of Au(2). The glass matrix is, however, stable for years, and is hence perfectly suited for various applications. If the irradiated gold-doped sample is annealed at 550 degrees C a bright green luminescence can be recognized. Intense 337 nm excitation induces a decrease of the green luminescence and the reappearance of the 753 nm Au(2) emission, indicating a strong interrelationship between both luminescence centers. Time-dependent density functional theory (TD-DFT) calculations indicate that the green luminescence can be assigned to noble metal dimers bound to silanolate centers. These complexes are recognized as the first stages in the further cluster growth process, which has been investigated with small-angle x-ray scattering (SAXS). In silver-doped glasses, Ag(0) atoms can be identified with electron paramagnetic resonance (EPR) spectroscopy after synchrotron activation. Annealing at 300 degrees C decreases the concentration of Ag(1), but induces an intense white light emission with 337 nm excitation. The white luminescence can be decomposed into bands that are attributed to small silver clusters such as Ag(2), Ag(3) and Ag(4), and an additional band matching the green emission of gold-doped glasses.

Measuring Patient Safety Culture in Romania Using the Hospital Survey on Patient Safety Culture (HSOPSC).

Purpose To explore patient safety culture among Romanian staff, using the U.S. Hospital Survey on Patient Safety Culture (HSOPSC). MATERIAL AND METHODS: A cross-sectional study was carried out in six hospitals, located in four Romanian regions (Craiova, Cluj-Napoca, Bucharest and Brasov), based on staff census in the Units/hospitals which volunteered to participate in the study (N=1,184). The response rate was 84%. The original questionnaire designed by the American Agency for Healthcare Research and Quality was translated into Romanian (with back translation), pre-tested before application and psychometrically checked. It consists of 42 questions grouped in 12categories, covering multiple aspects of patient safety culture (dimensions). Percentages of positive responses (PPRs) by question and category were analyzed overall and by staff profession. RESULTS: Most respondents were nurses (69%). The main work areas were surgery (24%) and medicine (22%). The highest PPRs were for Supervisor/Manager Expectations & Actions Promoting Safety (88%), Teamwork Within Units (86%), Handoffs and Transitions (84%), Organizational Learning-Continuous Improvement (81%), Overall Perceptions of Safety (80%), Feedback & Communication About Error (75%). The lowest PPRs were for: Staffing (39%), Frequency of Events Reported (59%) and Non-punitive Response to Errors (61%). Nurses exhibited significantly higher PPRs than doctors. CONCLUSIONS: This small-scale study of staff's attitude towards patient safety in Romanian hospitals suggests that there is room for future improvement, especially within the doctor category. Further research should assess the relationship between patient safety culture and frequency of adverse events.

The simultaneous occurrence of multiple myeloma and JAK2 positive myeloproliferative neoplasms - Report on two cases.

Multiple myeloma and JAK2 positive chronic myeloproliferative neoplasms are hematologic malignancies with a completely different cellular origin. Two cases of simultaneous occurrence of multiple myeloma, one with primary myelofibrosis and another one with essential thrombocythemia are reported in this article. In such cases, an accurate diagnosis requires a molecular testing, including gene sequencing and differential diagnosis of pancytosis associated with splenic amyloidosis. In general, in such cases, of two coexisting malignant hematologic diseases, the treatment of the most aggressive one is recommended. For our two cases, it was decided to start a Velcade based therapy. The main concern was the medullar toxicity, especially when a multiple myeloma was associated with a primary myelofibrosis.

Simplified model of low energy x-ray backscattering.

The reflection of x-rays from a half space is studied within the framework of a model that assumes multiple isotropic scattering of photons without energy loss. An exactly solvable analytical expression for the angular distribution of reflected photons is derived. The range of validity of the model was determined by the Monte Carlo simulation thereby incorporating energy loss and angular dependences. For water as a scatterer, in the energy range from 10 to 60 keV, which is often used in x-ray diagnostics, the two approaches differ by at most 5%. The analytic results, confirmed by the Monte Carlo simulation, show that the angular distribution of reflected photons for energies greater than 30 keV--where multiple scattering events dominate--may be represented by a cosine law, within a few per cent of accuracy.

[Serpiginous choroiditis--the diagnostic problems]. / Coroidita serpiginoasa--probleme de diagnostic.

Serpiginous choroiditis is a very rare ocular disease with an unknown etiology. This paper presents the case of a patient with serpiginous choroiditis and the diagnosis problems of this case.

[The results of multimodal treatment in retinoblastoma]. / Rezultate ale tratamentului multimodal în retinoblastom.

The paper is a retrospective study about complex treatment (surgery, chemotherapy and radiotherapy) in a group of 25 patients with retinoblastoma. The best results were in patients with early diagnosis, who came soon after surgery for chemotherapy and radiotherapy. Non presentation for chemotherapy and radiotherapy was the main cause of therapeutical fail.

[Orthoptic treatment efficiency in convergence insufficiency treatment]. / Eficienta tratamentului ortoptic în terapia insuficientei de convergenta.

We studied a group of 162 patients(89 females, 73 males), with ages between 15-30 years, who complained of blurred vision at near work. 98 patients(60.4%) were diagnosed with convergence insufficiency (C.I.), the rest of 64 patients(39.6%) had: low refractive errors, heterophoria and intermittent heterotropia. Patients with convergence insufficiency were divided in 3 groups: group 1(34 patients--34.6%) were treated with orthoptic exercises and near point exercises at home, group 2 (34 patients--34.6%) were treated with only near point exercises at home and control group 3 (30 patients--30.8%) without treatment. The result of the treatment of C.I. was good at 25 patients(73.5%) of group 1, at 8 patients(23.5%) of group 2 while in group 3 at only one patient the symptoms disappeared.

[Retinoschisis--the clinical associations and therapeutic possibilities]. / Retinoschizis--asocieri clinice si posibilitati terapeutice.

Retinoschisis is a vitreo retinal dystrophy characterized by splitting of the neuroretinal layers. The paper presents two cases of retinoschisis associated with retinal detachment. As a particularity, one patient was diagnosed with von Willebrand disease and the other one, with otomandibular dysostosis (Francois-Haustrade). There are presented therapeutical methods used in this two cases: Laser, Argon photocoagulation, transscleral cryopexia, scleral buckling and also the functional and anatomical results.

A time-frequency approach for the analysis of normal and arrhythmia cardiac signals.

Previously, electrocardiogram (ECG) signals have been analyzed in either a time-indexed or spectral form. The reality, is that the ECG and all other biological signals belong to the family of multicomponent nonstationary signals. Due to this reason, the use of time-frequency analysis can be unavoidable for these signals. The Husimi and Wigner distributions are normally used in quantum mechanics for phase space representations of the wavefunction. In this paper, we introduce the Husimi distribution (HD) to analyze the normal and abnormal ECG signals in time-frequency domain. The abnormal cardiac signal was taken from a patient with supraventricular arrhythmia. Simulation results show that the HD has a good performance in the analysis of the ECG signals comparing with the Wigner-Ville distribution (WVD).

[Fibrinolysis during pregnancy. The pre- and postpartal changes]. / Fibrinoliza în cursul sarcinii. Modificari pre si post partum.

Our previous research as well as data in literature (Yuasas, Ishizawa M.--1992) emphasised increased plasma fibrinolytic activity (PFA) in women during labor. Starting from these data we have tried to observe plasma fibrinolytic activity studied through euglobulin lysis time (ELT) in women during pregnancy and after delivery. We studied 25 healthy pregnant women aged between 18 and 30 years which were tested in the seventh month, during labour and at 48 hours after delivery. Blood samples were taken from the antecubital vein by venous puncture. The study showed an increased PFA (shortened ELT) only during labor; in the seventh month and at 48 hours after delivery ELT had almost the same values.

[The effect of continuous illumination and an inverse rhythm (light-darkness) on fibrinolysis]. / Efectul iluminarii continue si a ritmului inversat (lumina-întuneric) asupra fibrinolizei.

The studies of chronobiology on biological phenomena revealed the existence of a human internal mechanism ("biological clock") which controls biological events according to each function of the body. Most of the programmed and genetically fixed rhythms can be changed and synchronized by external factors. Starting from these data and from our previous studies which emphasised an intradian rhythm of the proteolytic blood coagulation and fibrinolytic systems we observed the behaviour of the fibrinolytic system in modified environmental conditions (continuous illumination and inversed day-night rhythm). Our experiments were performed on 180 Wistar rats both male and female, submitted to continuous illumination and inversed rhythm for 1, 3 and 5 weeks. We studied plasma fibrinolytic activity (PFA) through euglobulin lysis time (ELT) at three different moments of the day: 8:30, 18:30 and 8:30 the next day. The study revealed intradian variations of PFA regardless of the type and time of submission. Thus: continuous illumination for 1, 3, 5 weeks determined a decrease of PFA (prolonged ELT) during the second part of the day, less important at 5 weeks. Inversed day-night rhythm for 1 and 3 weeks determined the same intradian behaviour of PFA but less important than continuous illumination. PFA variations in our experimental conditions suggest an alteration of its biological rhythm.

Diurnal behaviour of some salivary parameters in patients with diabetes mellitus (protein concentration, amylase activity, density)--note I.

The study was carried out on 31 diabetic patients of both sexes hospitalised in the Clinical Hospital of Diabetes and Nutritional Diseases "Dr. I. Cantacuzino". They were divided in 2 groups: patients with insulin-dependent diabetes (IDDM) and noninsulin-dependent diabetes (NIDDM) and compared with a group of control non-diabetic subjects. Total mixed saliva was sampled in the morning (07:30-08:00) and in the afternoon (17:30-18:00) without stimulation and tested for amylase activity, proteins and density. The study revealed that the density and the amylase activity have the same diurnal behaviour for the diabetic patients and healthy control subjects either. The only difference was the amplitude of maximal activity (in the morning for density and in the afternoon for the amylase activity). Salivary proteins have a similar diurnal behaviour for both diabetic groups (maximal values in the morning and minimal values in the afternoon) in contrast to healthy control subjects that presented less obvious diurnal changes.

Diurnal behaviour of some salivary parameters in patients with diabetes mellitus (flow rate, pH, thiocianat, LDH activity)--note II.

The study was performed on 31 diabetic patients of both sexes, divided in 2 groups: group I--17 patients with insulin-dependent diabetes (IDDM) and group II--14 patients with noninsulin-dependent diabetes (NIDDM) and compared with a control group of 16 non-diabetic subjects. Mixed saliva was sampled without stimulation during 2 periods of the day: 07:30-08:00 before breakfast and 17:30-18:00 before dinner. We determined: salivary flow rate, pH with Merck indicator and, after homogenization, the thiocianat with the FeCl3 method and LDH activity (the Norbert method adapted in our laboratory for saliva). Our study showed the same diurnal changes in flow rate and salivary pH in both diabetic and control groups: minimal values in the morning and maximal ones in the afternoon. In non-smoking diabetic patients the salivary thiocianat had maximal values in the morning and minimal ones in the afternoon; similar behaviour, but less obvious was observed in smoking diabetic patients and in the control group regardless of the smoking habit. LDH activity showed unsignificant diurnal variations in the diabetic patients. In the control group we found a significant decrease of LDH activity in the afternoon. The discussion is about the implication of these salivary parameters in the pathology of oral cavity: gingivitis, periodontitis and caries in diabetic patients.