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1.
Sci Rep ; 13(1): 9271, 2023 Jun 07.
Article in English | MEDLINE | ID: mdl-37286629

ABSTRACT

We study the interplay between electronic correlations and hybridization in the low-energy electronic structure of CaMn[Formula: see text]Bi[Formula: see text], a candidate hybridization-gap semiconductor. By employing a DFT+U approach we find both the antiferromagnetic Néel order and band gap in good agreement with the corresponding experimental values. Under hydrostatic pressure, we find a crossover from hybridization gap to charge-transfer insulting physics due to the delicate balance of hybridization and correlations. Increasing the pressure above [Formula: see text] GPa we find a simultaneous pressure-induced volume collapse, plane-to-chain, insulator to metal transition. Finally, we have also analyzed the topology in the antiferromagnetic CaMn[Formula: see text]Bi[Formula: see text] for all pressures studied.

2.
Actas dermo-sifiliogr. (Ed. impr.) ; 112(5): 434-440, mayo 2021. tab, ilus
Article in Spanish | IBECS | ID: ibc-212686

ABSTRACT

Antecedentes y objetivo: La incidencia del melanoma se ha incrementado significativamente y la forma más efectiva para disminuir su mortalidad es el diagnóstico precoz. La dermatoscopia aumenta la sensibilidad en el diagnóstico del melanoma, y por medio del análisis de las estructuras dermatoscópicas es posible estimar su grosor. Nuestro objetivo fue analizar la influencia del Breslow en las características dermatoscópicas del melanoma. Materiales y métodos: Estudio observacional de corte transversal. Se incluyeron pacientes con melanoma confirmado histológicamente y una imagen dermatoscópica del mismo. Se dividieron en tres grupos, melanoma in situ, melanoma fino (< 1 mm de Breslow) y melanoma grueso (≥ 1 mm de Breslow), y se analizaron el sexo, la edad, la localización, las características histológicas y las características dermatoscópicas. Resultados: Se analizaron 215 pacientes, 88 con melanoma in situ, 73 con melanoma fino y 54 con melanoma grueso. Las estructuras dermatoscópicas que incrementaron su frecuencia a medida que aumentó el Breslow del melanoma fueron el velo azul blanquecino (p < 0,001), las estructuras blanco brillantes (p < 0,001) y las áreas rojo lechosas (p < 0,003). Por otro lado, las líneas anguladas disminuyeron su frecuencia a medida que se incrementó el Breslow (p < 0,002). Conclusiones: La evaluación dermatoscópica tiene un importante rol, no solo en la precisión diagnóstica de las lesiones pigmentadas, sino también en ayudarnos a estimar el grosor preoperatorio del melanoma (AU)


Background and objective: The incidence of melanoma has increased significantly, and early diagnosis is the most effective way to reduce associated deaths. Dermoscopy increases diagnostic accuracy in melanoma and analysis of dermoscopic structures can help in the estimation of tumor thickness. The aim of this study was to analyze the influence of Breslow thickness on the dermoscopic characteristics of melanoma. Material and methods: Observational, cross-sectional study of patients with histologically confirmed melanoma and dermoscopic images of the tumor. The patients were divided into three groups: melanoma in situ, thin melanoma (≥ 1 mm Breslow thickness), and thick melanoma (≥ 1 mm Breslow thickness). Age, sex, tumor location, and histologic and dermoscopic characteristics were analyzed in all cases. Results: We studied 215 patients: 88 with melanoma in situ, 73 with thin melanoma, and 54 with thick melanoma. The frequency of the following dermoscopic features increased with increasing Breslow thickness: the blue-white veil (p < 0.001), white shiny structures (p < 0.001), and milky-red areas (p < 0.003). Angulated lines, by contrast, became less common with increasing thickness (p < 0.002). Conclusions: Dermoscopy not only improves diagnostic accuracy for pigmented lesions but also helps in the preoperative assessment of Breslow thickness in melanoma (AU)


Subject(s)
Humans , Male , Female , Middle Aged , Aged , Skin Neoplasms/diagnostic imaging , Melanoma/diagnostic imaging , Dermoscopy/methods , Sensitivity and Specificity , Cross-Sectional Studies
3.
Actas Dermosifiliogr (Engl Ed) ; 112(5): 434-440, 2021 May.
Article in English, Spanish | MEDLINE | ID: mdl-33259813

ABSTRACT

BACKGROUND AND OBJECTIVE: The incidence of melanoma has increased significantly, and early diagnosis is the most effective way to reduce associated deaths. Dermoscopy increases diagnostic accuracy in melanoma and analysis of dermoscopic structures can help in the estimation of tumor thickness. The aim of this study was to analyze the influence of Breslow thickness on the dermoscopic characteristics of melanoma. MATERIAL AND METHODS: Observational, cross-sectional study of patients with histologically confirmed melanoma and dermoscopic images of the tumor. The patients were divided into three groups: melanoma in situ, thin melanoma (≥ 1 mm Breslow thickness), and thick melanoma (≥ 1 mm Breslow thickness). Age, sex, tumor location, and histologic and dermoscopic characteristics were analyzed in all cases. RESULTS: We studied 215 patients: 88 with melanoma in situ, 73 with thin melanoma, and 54 with thick melanoma. The frequency of the following dermoscopic features increased with increasing Breslow thickness: the blue-white veil (p < 0.001), white shiny structures (p < 0.001), and milky-red areas (p < 0.003). Angulated lines, by contrast, became less common with increasing thickness (p < 0.002). CONCLUSIONS: Dermoscopy not only improves diagnostic accuracy for pigmented lesions but also helps in the preoperative assessment of Breslow thickness in melanoma.


Subject(s)
Melanoma , Skin Neoplasms , Cross-Sectional Studies , Dermoscopy , Humans , Melanoma/diagnostic imaging , Retrospective Studies , Skin Neoplasms/diagnostic imaging
4.
Phys Rev B ; 101(21)2020 Jun.
Article in English | MEDLINE | ID: mdl-34141976

ABSTRACT

We report the electronic and magnetic properties of stoichiometric CeAuBi2 single crystals. At ambient pressure, CeAuBi2 orders antiferromagnetically below a Néel temperature (TN ) of 19 K. Neutron diffraction experiments revealed an antiferromagnetic propagation vector τ ^ = [ 0 , 0 , 1 ∕ 2 ] , which doubles the paramagnetic unit cell along the c axis. At low temperatures several metamagnetic transitions are induced by the application of fields parallel to the c axis, suggesting that the magnetic structure of CeAuBi2 changes as a function of field. At low temperatures, a linear positive magnetoresistance may indicate the presence of band crossings near the Fermi level. Finally, the application of external pressure favors the antiferromagnetic state, indicating that the 4f electrons become more localized.

5.
Phys Rev B ; 102(19)2020 Nov.
Article in English | MEDLINE | ID: mdl-37720206

ABSTRACT

We report the evolution of the magnetic properties of Ce2Rh1-xIrxIn8-yCdy single crystals. In particular, for Ce2Rh0.5Ir0.5In8 (TN=2.0K) and Ce2Rh0.5Ir0.5In7.79Cd0.21 (TN=4.2K), we have solved the magnetic structure of these compounds using single-crystal neutron magnetic diffraction experiments. Taking the magnetic structure of the Ce2RhIn8 heavy-fermion antiferromagnet as a reference, we have identified no changes in the q=12,12,0 magnetic wave vector; however, the direction of the ordered Ce3+ moments rotates toward the ab plane, under the influence of both dopants. By constraining the analysis of the crystalline electric field (CEF) with the experimental ordered moment's direction and high-temperature magnetic-susceptibility data, we have used a mean-field model with tetragonal CEF and exchange interactions to gain insight into the CEF scheme and anisotropy of the CEF ground-state wave function when Cd and Ir are introduced into Ce2RhIn8. Consistent with previous work, we find that Cd doping in Ce2RhIn8 tends to rotate the magnetic moment toward the ab plane and lower the energy of the CEF excited states' levels. Interestingly, the presence of Ir also rotates the magnetic moment towards the ab plane although its connection to the CEF overall splitting evolution for the y = 0 samples may not be straightforward. These findings may shed light on the origin of the disordered spin-glass phase on the Ir-rich side of the phase diagram and also indicate that the Ce2MIn8 compounds may not follow exactly the same Rh-Ir CEF effects trend established for the Ce2MIn5 compounds.

6.
Phys Rev B ; 102(11)2020 Sep.
Article in English | MEDLINE | ID: mdl-37720400

ABSTRACT

We have performed X-ray powder diffraction, magnetization, electrical resistivity, heat capacity and inelastic neutron scattering (INS) to investigate the physical properties of the intermetallic series of compounds CeCuBi2-xSbx. These compounds crystallize in a tetragonal structure with space group P4∕nmm and present antiferromagnetic transition temperatures ranging from 3.6 K to 16 K. Remarkably, the magnetization easy axis changed along the series, which is closely related to the variations of the tetragonal crystalline electric field (CEF) parameters. This evolution was analyzed using a mean field model, which included an anisotropic nearest-neighbor interactions and the tetragonal CEF Hamiltonian. We obtained the CEF parameters by fitting the magnetic susceptibility data with the constraints given by the INS measurements. More broadly, we discuss how this CEF evolution can affect the Kondo physics and the search for a superconducting state in this family.

7.
Parasitol Int ; 75: 102037, 2020 Apr.
Article in English | MEDLINE | ID: mdl-31841659

ABSTRACT

The aim of this study was to assess the immune response and the protective efficacy elicited by the vaccination with the recombinant Fasciola hepatica myosin regulatory light chain (FhrMRLC) in Adjuplex® adjuvant against the infection with F. hepatica in rats. Four groups of 15 animals each were used for the study, one group was immunized with the recombinant F. hepatica MRLC in Adjuplex® adjuvant and the other groups remained as adjuvant, positive and negative control groups. The parasitological study showed that a statistically significant reduction of 65.1% and 82.1% in fluke burden and fecal egg count, respectively, was detected in vaccinated animals. In addition, vaccination with FhrMRLC induced a well-defined humoral and cellular immune response characterized by a significant production of specific IgG and IL-2, IL-12, TNF-α and IFN-γ; which confirms the immunogenic capacity of the FhrMRLC.


Subject(s)
Fasciola hepatica/physiology , Fascioliasis/immunology , Immunization , Myosin Light Chains/therapeutic use , Th1 Cells/immunology , Animals , Immunity, Cellular , Immunity, Humoral , Male , Myosin Light Chains/immunology , Rats , Rats, Wistar , Recombinant Proteins/immunology , Recombinant Proteins/therapeutic use
8.
J Phys Condens Matter ; 31(49): 495402, 2019 Dec 11.
Article in English | MEDLINE | ID: mdl-31284273

ABSTRACT

Raman scattering, synchrotron x-ray diffraction, specific heat, resistivity and magnetic susceptibility measurements were performed in Sr(Fe1-x Co x )2As2 [[Formula: see text]] single crystals with superconducting critical temperature [Formula: see text] K and two additional transitions at 132 and 152 K observed in both specific heat and resistivity data. A quasielastic Raman signal with B 2g symmetry (tetragonal cell) associated with electronic nematic fluctuations is observed. Crucially, this signal shows maximum intensity at [Formula: see text] K, marking the nematic transition temperature. X-ray diffraction shows evidence of coexisting orthorhombic and tetragonal domains between [Formula: see text] and [Formula: see text] ∼ 152 K, implying that precursor orthorhombic domains emerge over an extended temperature range above [Formula: see text]. While the height of the quasielastic Raman peak is insensitive to [Formula: see text], the temperature-dependence of the average nematic fluctuation rate indicates a slowing down of the nematic fluctuations inside the precursor orthorhombic domains. These results are analogous to those previously reported for the LaFeAsO parent oxypnictide (Kaneko et al 2017 Phys. Rev. B 96 014506). We propose a scenario where the precursor orthorhombic phase may be generated within the electronically disordered regime ([Formula: see text]) as long as the nematic fluctuation rate is sufficiently small in comparison to the optical phonon frequency range. In this regime, the local atomic structure responds adiabatically to the electronic nematic fluctuations, creating a net of orthorhombic clusters that, albeit dynamical for [Formula: see text], may be sufficiently dense to sustain long-range phase coherence in a diffraction process up to [Formula: see text].

9.
J Phys Condens Matter ; 30(37): 375601, 2018 Sep 19.
Article in English | MEDLINE | ID: mdl-30074484

ABSTRACT

We report in-plane electrical resistivity studies of CeCuBi2 and LaCuBi2 single crystals under applied pressure. At ambient pressure, CeCuBi2 is a c-axis Ising antiferromagnet with a transition temperature [Formula: see text] K. In a magnetic field applied along the c-axis at [Formula: see text] K a spin-flop transition takes place [Formula: see text] T. Applying pressure on CeCuBi2 suppresses T N at a slow rate. [Formula: see text] extrapolates to zero temperature at [Formula: see text] GPa. The critical field of the spin-flop transition [Formula: see text] displays a maximum of 6.8 T at [Formula: see text] GPa. At low temperatures, a zero-resistance superconducting state emerges upon the application of external pressure having a maximum T c of 7 K at 2.6 GPa in CeCuBi2. High-pressure electrical-resistivity experiments on the non-magnetic reference compound LaCuBi2 reveal also a zero resistance state with similar critical temperatures in the same pressure range as CeCuBi2. The great similarity between the superconducting properties of both materials and elemental Bi suggests a common origin of the superconductivity. We discuss that the appearance of this zero resistance state superconductivity may be related to the Bi layers present in the crystalline structure of both compounds and, therefore, could be intrinsic to CeCuBi2 and LaCuBi2, however further experiments under pressure are necessary to clarify this issue.

10.
J Helminthol ; 91(4): 462-469, 2017 Jul.
Article in English | MEDLINE | ID: mdl-27460135

ABSTRACT

The aim of this study was to analyse the oxidative and anti-oxidant status in serum samples from dairy cows naturally infected by Dictyocaulus viviparus and its relation with pathological analyses. The diagnosis of the disease was confirmed by necropsy of one dairy cow with heavy infection by the parasite in the lungs and bronchi. Later, blood and faeces were collected from another 22 cows from the same farm to measure reactive oxygen species (ROS) levels, thiobarbituric acid-reactive substances (TBARS), catalase (CAT) and superoxide dismutase (SOD) activities on day 0 (pre-treatment) and day 10 (post-treatment with eprinomectin). Faecal examination confirmed the infection in all lactating cows. However, the number of D. viviparus larvae per gram of faeces varied between animals. Cows showed different degrees of severity according to respiratory clinical signs of the disease (cough and nasal secretion). Further, they were classified and divided into two groups: those with mild (n = 10) and severe disease (n = 12). Increased levels of TBARS (P < 0.001), ROS (P = 0.002) and SOD activity (P < 0.001), as well as reduced CAT activity (P < 0.001) were observed in cows with severe clinical signs of the disease compared to those with mild clinical signs. Eprinomectin treatment (day 10) caused a reduction of ROS levels (P = 0.006) and SOD activity (P < 0.001), and an increase of CAT activity (P = 0.05) compared to day 0 (pre-treatment). TBARS levels did not differ with treatment (P = 0.11). In summary, increased ROS production and lipid peroxidation altered CAT and SOD activities, as an adaptive response against D. viviparus infection, contributing to the occurrence of oxidative stress and severity of the disease. Treatment with eprinomectin eliminated the infection, and thus minimized oxidative stress in dairy cows.


Subject(s)
Cattle Diseases/pathology , Dictyocaulus Infections/pathology , Dictyocaulus/isolation & purification , Oxidative Stress , Animals , Bronchi/parasitology , Catalase/blood , Cattle , Cattle Diseases/parasitology , Feces/parasitology , Lung/parasitology , Parasite Egg Count , Reactive Oxygen Species/blood , Superoxide Dismutase/blood , Thiobarbituric Acid Reactive Substances/analysis
11.
J Phys Condens Matter ; 27(14): 145701, 2015 Apr 15.
Article in English | MEDLINE | ID: mdl-25786492

ABSTRACT

We report a combined study of external pressure and Cu-substitution on BaFe2As2 single crystals grown by the in-flux technique. At ambient pressure, the Cu-substitution is known to suppress the spin density wave (SDW) phase in pure BaFe2As2(T(SDW) ≈ 140 K) and to induce a superconducting (SC) dome with a maximum transition temperature T(c)(max) ≃ 4.2 K. This T(c)(max) is much lower than the T(c) ∼ 15-28 K achieved in the case of Ru, Ni and Co substitutions. Such a lower T(c) is attributed to a Cu(2+) magnetic pair-breaking effect. The latter is strongly suppressed by applied pressure, as shown herein, Tc can be significantly enhanced by applying high pressures. In this work, we investigated the pressure effects on Cu(2+) magnetic pair-breaking in the BaFe(2-x)Cu(x)As2 series. Around the optimal concentration (x(opd) = 0.11), all samples showed a substantial increase of T(c) as a function of pressure. Yet for those samples with a slightly higher doping level (over-doped regime), T(c) presented a dome-like shape with maximum T(c) ≃ 8 K. Remarkably interesting, the under-doped samples, e.g. x = 0.02 display a maximum pressure induced T(c) ≃ 30 K which is comparable to the maximum T(c)'s found for the pure compound under external pressures. Furthermore, the magnetoresistance effect as a function of pressure in the normal state of the x = 0.02 sample also presented an evolution consistent with the screening of the Cu(2+) local moments. These findings demonstrate that the Cu(2+) magnetic pair-breaking effect is completely suppressed by applying pressure in the low concentration regime of Cu(2+) substituted BaFe2As2.

12.
Sci Rep ; 4: 6252, 2014 Sep 01.
Article in English | MEDLINE | ID: mdl-25176407

ABSTRACT

The possible existence of a sign-changing gap symmetry in BaFe2As2-derived superconductors (SC) has been an exciting topic of research in the last few years. To further investigate this subject we combine Electron Spin Resonance (ESR) and pressure-dependent transport measurements to investigate magnetic pair-breaking effects on BaFe1.9M0.1As2 (M = Mn, Co, Cu, and Ni) single crystals. An ESR signal, indicative of the presence of localized magnetic moments, is observed only for M = Cu and Mn compounds, which display very low SC transition temperature (Tc) and no SC, respectively. From the ESR analysis assuming the absence of bottleneck effects, the microscopic parameters are extracted to show that this reduction of Tc cannot be accounted by the Abrikosov-Gorkov pair-breaking expression for a sign-preserving gap function. Our results reveal an unconventional spin- and pressure-dependent pair-breaking effect and impose strong constraints on the pairing symmetry of these materials.

13.
Minerva Cardioangiol ; 59(6): 533-42, 2011 Dec.
Article in English | MEDLINE | ID: mdl-22134468

ABSTRACT

AIM: In high-risk hypertensive subjects (HTs) with incidental unilateral renal artery stenosis (RAS), the effectiveness of percutaneous revascularization with stent (PR-STENT) on blood pressure (BP) and glomerular filtration rate (GFR) is not established. METHODS: Eighteen HTs aged 65.7 ± 9.2 years with angiographically diagnosed unilateral RAS (≥ 60%) were randomized to receive PR-STENT (N=9) or to NO-STENT (N=9). BP (mercury sphygmomanometer) and GFR (99mTc-DTPA clearances during renal scintigraphy) were evaluated yearly for three years. Echo-Doppler of renal arteries was performed to verify the anatomic patency and flow velocities of the reperfused artery. Analysis of variance compared BP and GFR values changes from baseline to the follow-up; differences for continuous variables were evaluated between groups with the Tukey's post hoc test after adjustment for age, change of BP between baseline and at the follow-up, GFR and body mass index (BMI). RESULTS: Baseline systolic BP and GFR values were not different between groups. The significantly greater GFR increase observed in PR-STENT than in NO-STENT at univariate analysis at the end of follow-up (62.5 ± 19.2 vs. 42.24 ± 17.6, P<0.02) disappeared after adjustment for confounding factors. However, systolic BP remained significantly lower in PR-STENT than in NO-STENT (140.1 ± 4.6 vs. 170.0 ± 8.3, P<0.0001) also after adjustment for age, GFR and BMI. CONCLUSION: PR-STENT reduces systolic BP without improving GFR. Due to the strong association between high BP and renal damage, this study raises the question on whether PR-STENT should be performed in all HTs with unilateral and incidental RAS.


Subject(s)
Angioplasty, Balloon , Glomerular Filtration Rate , Hypertension/physiopathology , Hypertension/therapy , Renal Artery Obstruction/physiopathology , Renal Artery Obstruction/therapy , Stents , Aged , Algorithms , Analysis of Variance , Blood Pressure , Blood Pressure Determination , Female , Follow-Up Studies , Humans , Incidental Findings , Longitudinal Studies , Male , Middle Aged , Radionuclide Imaging , Renal Artery Obstruction/diagnostic imaging , Severity of Illness Index , Treatment Outcome , Ultrasonography
14.
Braz J Biol ; 70(2): 341-50, 2010 May.
Article in English | MEDLINE | ID: mdl-20379650

ABSTRACT

The ultrastructure of the reproductive gland, dorsal body (DB), of Megalobulimus abbreviatus was analysed. Electron microscope immunohistochemistry was used to detect FMRFamide-like peptides in the nerve endings within this gland. Nerve backfilling was used in an attempt to identify the neurons involved in this innervation. In M. abbreviatus, the DB has a uniform appearance throughout their supraesophageal and subesophageal portions. Dorsal body cells have several features in common with steroid-secreting gland cells, such as the presence of many lipid droplets, numerous mitochondria with tubular cristae and a developed smooth endoplasmic reticulum cisternae. Throughout the DB in M. abbreviatus numerous axonal endings were seen to be in contact with the DB cells exhibiting a synaptic-like structure. The axon terminals contained numerous electron-dense and scanty electron-lucid vesicles. In addition, the DB nerve endings exhibited FMRFamide immunoreactive vesicles. Injection of neural tracer into the DB yielded retrograde labelling of neurons in the metacerebrum lobe of the cerebral ganglia and in the parietal ganglia of the subesophageal ganglia complex. The possibility that some of these retrograde-labelled neurons might be FMRFamide-like neurons that may represent a neural control to the DB in M. abbreviatus is discussed.


Subject(s)
Endocrine Glands/ultrastructure , Neurons, Efferent/ultrastructure , Snails/ultrastructure , Animals , Endocrine Glands/innervation , FMRFamide/analysis , Immunohistochemistry
15.
Ultrasound Obstet Gynecol ; 34(4): 416-8, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19697393

ABSTRACT

OBJECTIVE: To investigate the clinical implications of two categories of fetal bilateral cleft lip and palate (BCLP): with premaxillary protrusion and with a flattened profile. METHODS: This was a retrospective study of fetuses with a prenatal diagnosis of BCLP at the Department of Obstetrics and Gynecology of the University of Bologna in the period 1991-2005. RESULTS: BCLP was diagnosed prenatally in 14 cases (mean gestational age at diagnosis, 21 (range, 12-36) weeks). In nine of these, there was a premaxillary pseudomass; in the remaining five, the profile was flat. Associated structural and/or chromosomal anomalies were found in two of the nine with a premaxillary pseudomass and in all five of those with a flat profile (P = 0.02). All fetuses with a flat profile had aneuploidies (three trisomy 18, one trisomy 13, one trisomy 8 mosaic), as did one of the nine with a premaxillary pseudomass. Eight of the pregnancies were terminated, including three of those with a premaxillary pseudomass and all five of those without. All continuing pregnancies resulted in live births, although one neonate affected by Krabbe's disease died shortly after birth. CONCLUSIONS: Our findings suggest that a third of cases of BCLP diagnosed in utero have a flat profile and these are at high risk of lethal aneuploidies.


Subject(s)
Abnormalities, Multiple/diagnostic imaging , Aneuploidy , Cleft Lip/diagnostic imaging , Cleft Palate/diagnostic imaging , Fetal Diseases/diagnostic imaging , Maxilla/diagnostic imaging , Abnormalities, Multiple/embryology , Abnormalities, Multiple/mortality , Cleft Lip/embryology , Cleft Lip/mortality , Cleft Palate/embryology , Cleft Palate/mortality , Female , Fetal Diseases/mortality , Gestational Age , Humans , Infant, Newborn , Maxilla/abnormalities , Maxilla/embryology , Pregnancy , Prognosis , Retrospective Studies , Ultrasonography, Prenatal
16.
Phys Rev E Stat Nonlin Soft Matter Phys ; 79(3 Pt 2): 036315, 2009 Mar.
Article in English | MEDLINE | ID: mdl-19392057

ABSTRACT

In this paper, the onset of motion of an isolated cylinder partially exposed to a shear flow is experimentally investigated. The experiments are performed in a small narrow channel which provides a vertical shear layer flow whose sizes correspond with the channel width. The bottom of the channel is smooth except in the test zone, at long distance from the inlet, where the cylinder is placed with its principal axis perpendicularly directed to the main flow. The geometry of the channel bottom at the test zone is such that the cylinder is partially buried and presents different expositions to the incident flow. In this way, the geometrical constraints imposed by the sediment bed on a single particle in a natural sediment transport situation are reproduced in an idealized context. The results are interpreted in terms of the relation between the particle mobility parameter at the critical condition and the here defined particle burial degree with respect to the bed geometrical constraints beta . We emphasize the role played by this burial degree that is dependent on the particle exposure to the incident flow E and the resistance to the motion by mechanical contacts with its surroundings given by the so-called static pivot angle varphi .

17.
Ultrasound Obstet Gynecol ; 33(2): 209-12, 2009 Feb.
Article in English | MEDLINE | ID: mdl-19173235

ABSTRACT

OBJECTIVE: To evaluate if cervical length predicts prepartum bleeding and emergency Cesarean section in cases of placenta previa. METHODS: Between September 2005 and September 2007, cervical length was measured by transvaginal ultrasound in women with complete placenta previa persisting into the third trimester of pregnancy. A complete follow-up of pregnancy was obtained in all cases. RESULTS: Overall, 59 women were included in the study group. The mean +/- SD gestational age at ultrasound was 30.7 +/- 2.7 weeks and the cervical length was 36.9 +/- 8.8 mm. Cesarean delivery was performed in all cases, at a mean gestational age of 34.7 +/- 2.3 weeks. Twenty-nine (49.1%) of the women presented prepartum bleeding and 12 (20.3%) required an emergency Cesarean section prior to 34 completed weeks due to massive hemorrhage. Cervical length did not differ significantly between cases with and those without prepartum bleeding (35.3 +/- 9.3 mm vs. 38.4 +/- 8.2 mm; P = 0.18), but was significantly shorter among patients who underwent emergency Cesarean section < 34 weeks due to massive hemorrhage compared with patients who underwent elective Cesarean section (29.4 +/- 5.7 mm vs. 38.8 +/- 8.5 mm; P = 0.0006). CONCLUSIONS: Transvaginal sonographic cervical length predicts the risk of emergency Cesarean section < 34 weeks in women with complete placenta previa.


Subject(s)
Cervical Length Measurement , Cesarean Section/statistics & numerical data , Obstetric Labor, Premature/etiology , Placenta Previa/diagnostic imaging , Uterine Hemorrhage , Adult , Female , Humans , Predictive Value of Tests , Pregnancy , Pregnancy Trimester, Third , Prospective Studies
18.
J Periodontal Res ; 38(4): 362-5, 2003 Aug.
Article in English | MEDLINE | ID: mdl-12828651

ABSTRACT

BACKGROUND: High alkaline phosphatase activity (ALP) is shown in the periodontal ligament due to the constant renewal of this tissue or pathological circumstances. We have previously shown that the activity level of this enzyme could be reflected at the serum level. OBJECTIVES: Because the local production of ALP in the periodontal ligament is often of the bone-type enzyme, we studied the activity of this isozyme among the other isoforms in the serum of patients with chronic periodontitis in comparison with that of control subjects. MATERIAL AND METHODS: This study included 83 patients (59 with periodontal disease, 24 as control group) and we determined the total seric ALP activity and the percentage of the different isoforms (essentially bone, kidney and intestinal-types) by Ektachem analyser and gel agarose electrophoresis respectively. CONCLUSIONS: By comparisons between the two groups, our results showed a relationship between loss of attachment in periodontal disease and a drop in bone ALP activity in serum. Moreover, these results suggested a gender based difference as well, with lower activity more frequent in women than in men.


Subject(s)
Alkaline Phosphatase/blood , Isoenzymes/blood , Periodontitis/enzymology , Adult , Bone and Bones/enzymology , Chronic Disease , Female , Humans , Intestines/enzymology , Liver/enzymology , Male , Periodontal Attachment Loss/enzymology , Sex Factors , Statistics, Nonparametric
19.
Biol Reprod ; 65(4): 1297-303, 2001 Oct.
Article in English | MEDLINE | ID: mdl-11566756

ABSTRACT

In vivo levels of mRNA and the specificity of the extrauterine environment on matrix metalloproteinase (MMP)-3, MMP-2, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 were evaluated in eutopic and ectopic endometrial tissue during the establishment of endometriosis in a rat model. Uteri and endometriotic implants were collected and frozen at 36 h, 2 wk, and 4 wk postsurgery to study in vivo mRNA levels. Intact uteri, uterine tissues implanted in the peritoneum or under the skin, and peritoneal adipose implants were collected at 2 wk, halved, and either frozen or cultured. Gene-specific reverse transcriptase-polymerase chain reaction was performed to detect and quantify MMP-2, MMP-3, and TIMP-1 mRNA levels. The peritoneal endometriotic implants progressed from avascularized implants, to vascularized red lesions, to well-established encapsulated cysts. In vivo, MMP-3 mRNA was detectable at all times in ectopic tissues but not in eutopic uterine tissues, whereas MMP-2 and TIMP-1 were ubiquitously expressed at all times in both tissues. In vitro, only MMP-3 mRNA levels were elevated in endometrial tissues collected from the intact uterine and from under the skin, at levels similar to in vivo endometriotic implant MMP-3. In conclusion, ectopic endometrial MMP-3 may participate in the process of invasion and tissue remodeling that is hypothesized to occur in the pathogenesis of endometriosis.


Subject(s)
Endometriosis/enzymology , Endometrium/enzymology , Gene Expression Regulation , Matrix Metalloproteinase 3/genetics , Animals , Endometriosis/pathology , Endometrium/transplantation , Female , Matrix Metalloproteinase 2/genetics , RNA, Messenger/analysis , Rats , Rats, Inbred Strains , Reverse Transcriptase Polymerase Chain Reaction , Tissue Inhibitor of Metalloproteinase-1/genetics , Uterus/enzymology
20.
J Clin Endocrinol Metab ; 86(6): 2553-61, 2001 Jun.
Article in English | MEDLINE | ID: mdl-11397854

ABSTRACT

Based on our previous observation that peritoneal endometriotic (PE) lesions synthesize in vivo substantially more haptoglobin (Hp) than related eutopic tissues, we hypothesized that this increase in Hp production was due to endometrial-peritoneal interactions. As interleukin-6 (IL-6) stimulates Hp in other tissues and is produced by endometrial cells, we tested our hypothesis by evaluating the effects of IL-6 on Hp production by PE cells, normal peritoneal (P) cells, and eutopic endometrial cells from women with (UE-E) and without endometriosis (UE-C) using semiquantitative RT-PCR and enzyme-linked immunoabsorbent assay. Endogenous production of IL-6 was also assessed. Treatment with human recombinant IL-6 and dexamethasone significantly increased Hp production by P or PE cells in a dose- and time-dependent manner (P < 0.05). Hp messenger ribonucleic acid was not detected in UE-E and UE-C cells in the absence or presence of IL-6 and dexamethasone. PE and UE-E cells expressed significantly more IL-6 messenger ribonucleic acid than P and UE-C cells (P < 0.05). Moreover, UE-E cells secreted 6 times more IL-6 protein than UE-C cells (P < 0.05). These findings support our hypothesis and suggest a novel endometrial-peritoneal interaction whereby locally synthesized IL-6 and Hp may participate in the establishment and persistence of peritoneal endometriosis.


Subject(s)
Endometriosis/metabolism , Haptoglobins/biosynthesis , Interleukin-6/pharmacology , Peritoneum/metabolism , Cells, Cultured , Culture Media/pharmacology , Endometriosis/pathology , Endometriosis/physiopathology , Endometrium/pathology , Endometrium/physiopathology , Enzyme-Linked Immunosorbent Assay , Female , Haptoglobins/genetics , Humans , Interleukin-6/biosynthesis , Peritoneum/pathology , Peritoneum/physiopathology , RNA, Messenger/metabolism , Reference Values , Reverse Transcriptase Polymerase Chain Reaction
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