Quantum Phase Transitions for an Integrable Quantum Rabi-like Model with Two Interacting Qubits.

A two-interacting-qubit quantum Rabi-like model with vanishing transverse fields on the qubit pair is studied. Independently of the coupling regime, this model can be exactly and unitarily reduced to two independent single-spin quantum Rabi models, where the spin-spin coupling plays the role of the transverse field. This transformation and the analytical treatment of the single-spin quantum Rabi model provide the key to prove the integrability of our model. The existence of different first-order quantum phase transitions, characterized by discontinuous two-spin magnetization, mean photon number, and concurrence, is brought to light.

Color Match of a Universal-shade Composite Resin for Restoration of Non-carious Cervical Lesions: An Equivalence Randomized Clinical Trial.

PURPOSE: The objective of this double-blind, split-mouth, randomized clinical trial was to evaluate the color match of a single-shade composite resin Admira Fusion X-tra in comparison with a multi-shade composite resin Admira Fusion in non-carious cervical lesion restorations (NCCLs). METHODS AND MATERIALS: One hundred and twenty restorations were performed on NCCLs with two restorative materials (n=60). After prophylaxis, the teeth were isolated with a rubber dam, and one universal adhesive was applied in the selective enamel etching strategy. For both groups, the restorations were inserted incrementally and light-cured. The values of the coordinates L*, a*, and b* in the cervical third before vs after the restorations and cervical vs middle third after the restorations were evaluated using a digital spectrophotometer after the coordinate values were used to calculate the CIEDE (ΔE00). The restorations were evaluated at baseline and after 7 days of clinical performance according to the FDI criteria. Statistical analysis was performed using the Chi-square test for all parameters. Color change was analyzed by Student t-test for paired samples (α=0.05). RESULTS: All restorations were evaluated after 7 days. Regarding the color measurement, no significant difference was observed when Admira Fusion was compared to Admira Fusion X-tra for any of the comparisons performed (p>0.05). However, the values of ΔE00 in the cervical third before vs after the restorations were higher when compared with ΔE00 observed when the cervical vs middle third after restorations were compared. All restorations received the score "clinically very good" after 7 days for all outcomes, including the subjective color match, when evaluated for FDI criterion. CONCLUSIONS: The single-shade composite resin used achieves the same color match when compared to a multi-shade composite resin after 7 days in NCCLs.

Unitary evolution for a two-level quantum system in fractional-time scenario.

The time-evolution operator obtained from the fractional-time Schrödinger equation (FTSE) is said to be nonunitary since it does not preserve the norm of the vector state in time. As done in the time-dependent non-Hermitian quantum formalism, for a traceless non-Hermitian two-level quantum system, we demonstrate that it is possible to map the nonunitary time-evolution operator in a unitary one. It is done by considering a dynamical Hilbert space with a time-dependent metric operator, constructed from a Hermitian time-dependent Dyson map, in respect to which the system evolves in a unitary way, and the standard quantum mechanics interpretation can be made properly. To elucidate our approach, we consider three examples of Hamiltonian operators and their corresponding unitary dynamics obtained from the solutions of FTSE, and the respective Dyson maps.

Imidazolium-based ionic liquids binding to DNA: Mechanical effects and thermodynamics of the interactions.

We performed a robust characterization of the molecular interactions between the DNA molecule and two imidazolium-based ionic liquids (ILs): 1-Butyl-3-methylimidazolium chloride ([bmim]Cl) and 1-Octyl-3-methylimidazolium chloride ([omim]Cl), using single molecule approaches (optical and magnetic tweezers) and bulk techniques (isothermal titration calorimetry and conductivity measurements). Optical and magnetic tweezers allowed us to obtain the changes on the mechanical properties of the DNA complexes formed with both ILs, as well as the relevant physicochemical (binding) parameters of the interaction. Despite the weak binding measured between DNA and the two ILs, we identify a transition on the regime of polymer elasticity of the complexes formed, which results in a relevant DNA compaction for high IL concentrations. In addition, isothermal titration calorimetry and conductivity complemented the single molecule investigation, giving a complete thermodynamic characterization of the interactions and allowing the identification of the most relevant driving forces at various different concentration ranges of the ILs. Based on the results obtained with all the employed techniques, we propose a model for the binding schemes involving DNA and both [bmim]Cl and [omim]Cl.

Effect of Dentin Moisture in Posterior Restorations Performed with Universal Adhesive: A Randomized Clinical Trial.

OBJECTIVES: This double-blind, randomized clinical trial evaluated the influence of dentin moisture on postoperative sensitivity (POS), as well as, on clinical performance in posterior bulk-fill composite restorations, using a universal adhesive, until 12 months after clinical service. METHODS AND MATERIALS: In accordance with a split-mouth design, 45 patients received posterior restorations, restored with a bulk-fill resin composite (Filtek Bulk Fill, 3M Oral Care) and a universal adhesive used in etch-and-rinse mode (SBU; Single Bond Universal Adhesive), which were applied on dry or moist dentin, with a cavity depth of at least 3 mm. Three operators placed 90 Class I/Class II restorations. Patients were evaluated for spontaneous and stimulated POS in the baseline, and after 48 hours, 7 days, and at 6 and 12 months. In addition, secondary parameters (marginal discoloration, marginal adaptation, fracture, and recurrent caries) were evaluated by World Dental Federation (FDI) criteria after 7 days and at 6 and 12 months. Statistical analyzes were performed using the Chi-square, Fisher exact, Friedman, Kruskall-Wallis, and Mann-Whitney tests (α=0.05). RESULTS: No significant spontaneous and stimulated POS was observed when SBU was applied in dry and moist dentin (p>0.05). A significant and higher risk of spontaneous POS (20.0%; 95%CI 10.9-33.82 for dry dentin and 22.22%; 95%CI 12.54-36.27 for moist dentin) occurred up to 48 hours after restoration placement for the dry and moist dentin groups (p<0.02). However, the POS intensity was mild up to 48 hours with no significant difference between dry and moist dentin groups (p>0.79). When secondary parameters were evaluated, no significant differences between the groups were observed. CONCLUSION: Dentin moisture did not influence POS in posterior bulk-fill composite restorations when associated with a universal adhesive applied in etch-and-rinse mode.

Trophoblast-macrophage crosstalk on human extravillous under Toxoplasma gondii infection.

INTRODUCTION: The interaction between human extravillous trophoblasts and macrophages has an important role in implantation and placentation. However, any dysfunction in this communication system is associated with pregnancy pitfalls, and a Toxoplasma gondii infection can be a potential problem in this crosstalk. Therefore, the aim of this study was to assess the influence of infected macrophages on cytokine production and the incidence of apoptosis in T. gondii-infected extravillous trophoblast cells. METHODS: HTR-8/SVneo cells were treated with supernatant from macrophages infected or not by T. gondii (conditioned medium) in order to analyze apoptosis and cytokine production in comparison to uninfected control conditions. RESULTS: The IL-6 secretion by HTR-8/SVneo cells increased synergistically by treatment with conditioned medium and T. gondii infection. The apoptosis index of HTR-8/SVneo cells was also upregulated by treatment with conditioned medium and infection. In addition, a low expression of Fas/CD95 and a high soluble FasL release were observed during infection, although no significant change was observed in the proliferation of T. gondii. DISCUSSION: The parasite modulates the high apoptosis index in HTR-8/SVneo cells in order to favor its establishment inside its host cells. On the other hand, the conditioned medium from uninfected macrophages restores the apoptosis rates, although the effect of the infection seems to be stronger. In conclusion, our results showed that T. gondii infection in human extravillous trophoblasts is able to modulate the trophoblast-macrophage crosstalk.

Lysine-vasopressin in the evaluation of the hypothalamic-pituitary-adrenal axis in children with allergic rhinitis treated with intranasal beclomethasone dipropionate or oral prednisone.

One of the complications of steroid therapy is the hypothalamic-pituitary-adrenal (HPA) axis' suppression, particularly in children where this can lead to growth suppression and other well known complications. Although there are a large number of studies on suppression of the HPA axis with the use of topical steroids, the subject is still controversial. We measured the HPA axis function in 3 groups of allergic children treated with: 1) intranasal beclomethasone dipropionate (BDP) 400 micrograms/day for 4 weeks or 2) BDP 800 micrograms/day for 4 weeks and 3) oral prednisone, 1 mg/kg/day for 2 weeks. The HPA response was obtained after lysine-vasopressin (LVP) stimulation. LVP acts on the pituitary or hypothalamus level, stimulating the whole axis. Peripheral blood samples through an intravenous line were obtained for serum cortisol measurement at zero, 30, 60, and 90 minutes after the intravenous injection of LVP, before and after the treatment period. Our results showed no suppression of the HPA axis in children medicated with BDP at either 400 micrograms/day or 800 micrograms/day. On the other hand, there was a suppression of the HPA axis after prednisone treatment (p < 0.05). During the LVP test some side effects, possibly due to systemic vasoconstriction, were noted such as abdominal pain, nausea and vomiting, and transient hypertension. In conclusion, intranasal BDP at the dose of 400 or 800 micrograms/day during 4 weeks did not induce HPA axis suppression. The LVP test is efficient to demonstrate HPA hypofunction or suppression and it produced only mild to moderate transient side effects. However, due to the side effects observed, a safer test such as urinary free cortisol (24 hours), should be used in the investigation of the HPA axis.

[A case of epilepsy simulating a pheochromocytoma]. / Un caso de epilepsia que simula un feocromocitoma.

INTRODUCTION: Autonomic epilepsy is a rare entity that results from an epileptogenic focus involving certain structures belonging to the autonomous nervous system; it is characterised by the occurrence of convulsive seizures that consist in autonomic phenomena. CASE REPORT: We report the case of a 28-year-old female patient who suffered paroxysmal episodes similar to those accompanying a pheochromocytoma. Following a thorough examination, both the presence of a tumour and the anomalous production of catecholamines were excluded and, although it was not possible to provide electroencephalographic evidence, the patient was diagnosed as suffering from autonomous epilepsy, which was later confirmed by the clinical efficacy of valproic acid therapy. CONCLUSIONS: Autonomic seizures often show characteristics that are singular or similar to those of other clinical entities. This makes the disorder difficult to diagnose and sometimes requires therapeutic testing with anticonvulsive drugs.

[Behcet's disease. Experience of an internal medicine service from 1982 to 1991]. / Doença de Behçet. Experiência de um serviço de medicina interna entre 1982 e 1991.

The authors present the results of a retrospective study on Behçet's disease, concerning 19 patients observed in Medicine Service 2 (Santo António dos Capuchos Hospital) between 1982 and 1991. There were 15 male and 4 female patients, with a mean age of 33. The clinical manifestations were: oral--100%, ocular--100%, genital--89%, articular--79%, cutaneous--68%, general non-specific manifestations--52%, venous--26%, peripheral nervous system--21%, central nervous system--10% and persistent headaches--10%.

[Favism]. / Favismo.

Favism is an acute hemolytic syndrome occurring in glucose-6-phosphate dehydrogenase (G6PD) deficient individuals after the consumption of fava beans. The authors report the clinical case of a 16 year-old boy admitted to hospital with an acute hemolytic episode after the ingestion of fava beans. Complementary studies revealed G6PD deficiency. A study of the family and a short review about favism is presented.

[Giant cell arteritis (Horton's disease): report of 18 cases]. / Arterite de células gigantes (Doença de Horton): a propósito de 18 casos.

The authors present and comment on 18 cases of Giant-cell arteritis observed in an Internal Medicine Department between 1984 and 1991 with emphasis on clinical aspects and diagnostic considerations, on the occult presentation forms and, finally, on two cases with peripheral neuropathy. The clinical manifestations were: headache (78%), general non-specific symptoms (78%), polymyalgia rheumatica (61%), sudden blindness (33%), local temporal signs (28%), jaw pain (24%), articular complaints (17%) and peripheral neuropathy (12%).

Dermatomyositis as the first manifestation of a lung tumor.

Dermatomyositis (DM) is a rare disease characterised by proximal muscle weakness and a typical cutaneous rash. The muscle biopsy shows inflammatory lesions consistent with myositis, being related to an increased risk of cancer, often considered as a paraneoplastic syndrome. The authors present a case of a 63-year-old man, with progressive proximal muscle weakness and cutaneous rash, appearing in two months. The muscle and skin biopsies were consistent with DM. Chest tomography showed a nodular image in the lingular region and bronchy biopsy confirmed the diagnosis of small cell lung carcinoma (SCLC). This clinical case intends to enhance the importance of a thorough diagnostic study in patients with DM, as it is often a paraneoplastic syndrome.

Epidermal growth factor receptor mutation study for 5 years, in a population of patients with non-small cell lung cancer.

INTRODUCTION: In 2006, the Vila Nova de Gaia/Espinho Hospital Centre Pulmonary Oncology Unit started performing EGFR (Epidermal Growth Factor Receptor) mutation sequencing in selected patients with NSCLC and systematically in all patients since 2010, regardless of histology, smoking habits, age or sex. The aim of this study was to characterize the group of patients that carried out the sequencing between 2006-2010, to determine EGFR mutation frequency, to evaluate the overall survival and the survival after the use of tyrosine kinase inhibitors (TKI), in patients who performed this therapy in second and third line, knowing the EGFR mutation status. METHODS: Descriptive statistical analysis of patients who did EGFR sequencing in 2006-2010 and of overall survival in patients treated with TKI as 2nd and 3rd line therapy. Record of the material available for analysis and average delay of exam results, according to the material submitted. RESULTS: The sequencing was performed in 374 patients, 71,1% males, 67,1% non/ex-smokers, 32,9% smokers, 57,8% adenocarcinoma and 23,5% squamous cell carcinoma (SCC). The mutation was detected in 49 patients (13,1%). In all studied patients, the mutation rate was 9% in males and 23% in females. Median overall survival after erlotinib use of was 14 months for patients with positive EGFR mutation versus 6 months in not mutated patients (p = 0.003). CONCLUSION: Our group had an overall mutation rate of 13.1% with female, non-smokers, adenocarcinoma histology predominance. In selected patients (2006/2009), the mutation rate was 16%, in not selected patients (2010) the mutation rate was 10.4%. This study has permitted a better understanding of the EGFR mutation rate in the Portuguese population as welll as an evaluation of the patients survival after the use of of tyrosine kinase inhibitors, in second and third line therapy with previous knowledge of the EGFR mutational status. Statistical significant differences in survival were found in the two patient groups (EGFR mutated and non mutated). The EGFR mutation research should be performed in all patients with NSCLC, giving the possibility to a considerable number of patients to perform a first line treatment with TKI (EGFR mutated patients) and the advantage of performing other chemotherapy schemes, when progression occurs.

Differential apoptosis in BeWo cells after infection with highly (RH) or moderately (ME49) virulent strains of Toxoplasma gondii is related to the cytokine profile secreted, the death receptor Fas expression and phosphorylated ERK1/2 expression.

INTRODUCTION: Alterations of apoptosis are commonly associated with pregnancy complications and abortion. Modulation of apoptosis is a relevant feature of Toxoplasma gondii infection and it is related to parasite strain types. The aim of the present study was to evaluate the possible factors that are involved in the differential apoptosis of BeWo cells infected with distinct T. gondii strain types. METHODS: Human trophoblastic cells (BeWo cell line) were infected with RH or ME49 strains, the cytokine production was measured and the phosphorylation of anti-apoptotic ERK1/2 protein was analyzed. Also, cells were treated with different cytokines, infected with RH or ME49 strain, and analyzed for apoptosis index and Fas/CD95 death receptor expression. RESULTS: ME49-infected BeWo cells exhibited a predominantly pro-inflammatory cytokine profile, whereas cells infected with RH strain had a higher production of anti-inflammatory cytokines. Also, the incidence of apoptosis was higher in ME49-infected cells, which have been treated with pro-inflammatory cytokines compared to cells infected with RH and treated with anti-inflammatory cytokines. Moreover, Fas/CD95 expression was higher in cells infected with either ME49 or RH strain and treated with pro-inflammatory cytokines compared to anti-inflammatory cytokine treatment. The phosphorylation of ERK1/2 protein increased after 24 h of infection only with the RH strain. CONCLUSION: These results suggest that opposing mechanisms of interference in apoptosis of BeWo cells after infection with RH or ME49 strains of T. gondii can be associated with the differential cytokine profile secreted, the Fas/CD95 expression and the phosphorylated ERK1/2 expression.

Trophoblast cells are able to regulate monocyte activity to control Toxoplasma gondii infection.

INTRODUCTION: Toxoplasma gondii is an intracellular parasite that causes severe disease when the infection occurs during pregnancy. Trophoblast cells constitute an important maternal-fetal barrier, with monocytes concentrating around them. Thus, interactions between trophoblasts and monocytes are important for maintaining a successful pregnancy, especially in cases of infection. This study aimed to evaluate the role of trophoblast cells (BeWo line) on monocyte (THP-1 line) activity in the presence or absence of T. gondii infection. METHODS: THP-1 cells were stimulated with supernatants of BeWo cells, previously infected or not with T. gondii, and then infected with parasites. The supernatant of both cells were collected and analyzed for cytokine production and T. gondii proliferation in THP-1 cells was determined. RESULTS: The results showed that after infection, the pattern of cytokines secreted by THP-1 and BeWo cells was characterized as a pro-inflammatory profile. Furthermore, supernatant of BeWo cells infected or not, was able to change the cytokine profile secreted by infected THP-1 cells, and this supernatant became THP-1 cells more able to control T. gondii proliferation than those that had not been stimulated. DISCUSSION: This effect was associated with secretion of interleukin (IL)-6 by the THP-1 cells and soluble factors secreted by BeWo cells, such as IL-6 and MIF. CONCLUSION: Together, these results suggest that trophoblast cells are able to modulate monocyte activity, resulting in the control of T. gondii infection and subsequent maintenance of pregnancy.

Apoptosis and S phase of the cell cycle in BeWo trophoblastic and HeLa cells are differentially modulated by Toxoplasma gondii strain types.

Transplacental transmission of Toxoplasma gondii causes congenital toxoplasmosis, one of the most severe forms of infection. The ability of the parasite to survive intracellularly largely depends on the blocking of different proapoptotic signaling cascades of the host cells. During pregnancy, however, alterations in the incidence of apoptosis are associated with abnormal placental morphology and function. The aim of this study was to evaluate the incidence of apoptosis and cell proliferation in trophoblastic (BeWo cell line) and uterine cervical (HeLa cell line) cells infected with a highly virulent RH strain or a moderately virulent ME49 strain of T. gondii. BeWo and HeLa cells were infected with RH or ME49 tachyzoites (2:1 and 5:1; parasite:cell) or medium alone (control). After 2 h, 6 h and 12 h of incubation, cells were fixed in 10% formalin and analyzed by immunohistochemistry to determine the apoptosis (expression of cytokeratin 18 neo-epitope--clone M30) and cell in S phase (expression of proliferating cell nuclear antigen--PCNA) indices. RH strain-infected BeWo and HeLa cells showed a lower apoptosis index than non-infected controls, whereas a higher apoptosis index was found in ME49 strain-infected cells compared to controls. In addition, RH-infected cells displayed lower apoptosis index than ME49-infected cells, even though active caspase-3 was detected in both cell types infected with either RH or ME49 strains as well in non-infected cells in all analyzed times of infection. Also, the cell S phase indices were higher in ME49 strain-infected BeWo and HeLa cells as compared to non-infected controls and RH strain-infected cells. These results indicate that RH and ME49 strains of T. gondii possess opposing mechanism of interference in apoptosis and cell cycle S phase of both BeWo and HeLa cells and these differences can be associated to evasion strategies of the parasite to survive inside the host cells.