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1.
Soft Matter ; 20(4): 923-939, 2024 Jan 24.
Artículo en Inglés | MEDLINE | ID: mdl-38189452

RESUMEN

We present a comprehensive numerical study of the phase behavior and dynamics of a three-dimensional active dumbbell system with attractive interactions. We demonstrate that attraction is essential for the system to exhibit nontrivial phases. We construct a detailed phase diagram by exploring the effects of the system's activity, density, and attraction strength. We identify several distinct phases, including a disordered, a gel, and a completely phase-separated phase. Additionally, we discover a novel dynamical phase, that we name percolating network, which is characterized by the presence of a spanning network of connected dumbbells. In the phase-separated phase we characterize numerically and describe analytically the helical motion of the dense cluster.

2.
Soft Matter ; 19(10): 1987-2000, 2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36847796

RESUMEN

We study the phase behaviour of cholesteric liquid crystal shells with different geometries. We compare the cases of tangential anchoring and no anchoring at the surface, focussing on the former case, which leads to a competition between the intrinsic tendency of the cholesteric to twist and the anchoring free energy which suppresses it. We then characterise the topological phases arising close to the isotropic-cholesteric transition. These typically consist of quasi-crystalline or amorphous tessellations of the surface by half-skyrmions, which are stable at lower and larger shell sizes, respectively. For ellipsoidal shells, defects in the tessellation couple to a local curvature, and according to the shell size, they either migrate to the poles or distribute uniformly on the surface. For toroidal shells, the variations in the local curvature of the surface stabilise heterogeneous phases where cholesteric or isotropic patterns coexist with hexagonal lattices of half-skyrmions.

3.
Phys Rev Lett ; 128(2): 027801, 2022 Jan 14.
Artículo en Inglés | MEDLINE | ID: mdl-35089738

RESUMEN

We study the phase behavior of a quasi-two-dimensional cholesteric liquid crystal shell. We characterize the topological phases arising close to the isotropic-cholesteric transition and show that they differ in a fundamental way from those observed on a flat geometry. For spherical shells, we discover two types of quasi-two-dimensional topological phases: finite quasicrystals and amorphous structures, both made up of mixtures of polygonal tessellations of half-skyrmions. These structures generically emerge instead of regular double twist lattices because of geometric frustration, which disallows a regular hexagonal tiling of curved space. For toroidal shells, the variations in the local curvature of the surface stabilizes heterogeneous phases where cholesteric patterns coexist with hexagonal lattices of half-skyrmions. Quasicrystals and amorphous and heterogeneous structures could be sought experimentally by self-assembling cholesteric shells on the surface of emulsion droplets.

4.
Soft Matter ; 15(41): 8251-8265, 2019 Oct 23.
Artículo en Inglés | MEDLINE | ID: mdl-31553342

RESUMEN

The rheological behaviour of an emulsion made of an active polar component and an isotropic passive fluid is studied by lattice Boltzmann methods. Different flow regimes are found by varying the values of the shear rate and extensile activity (occurring, e.g., in microtubule-motor suspensions). By increasing the activity, a first transition occurs from the linear flow regime to spontaneous persistent unidirectional macro-scale flow, followed by another transition either to a (low shear) intermittent flow regime with the coexistence of states with positive, negative, and vanishing apparent viscosity, or to a (high shear) symmetric shear thinning regime. The different behaviours can be explained in terms of the dynamics of the polarization field close to the walls. A maximum entropy production principle selects the most likely states in the intermittent regime.

5.
Sci Rep ; 10(1): 15936, 2020 09 28.
Artículo en Inglés | MEDLINE | ID: mdl-32985576

RESUMEN

We use computer simulations to study the morphology and rheological properties of a bidimensional emulsion resulting from a mixture of a passive isotropic fluid and an active contractile polar gel, in the presence of a surfactant that favours the emulsification of the two phases. By varying the intensity of the contractile activity and of an externally imposed shear flow, we find three possible morphologies. For low shear rates, a simple lamellar state is obtained. For intermediate activity and shear rate, an asymmetric state emerges, which is characterized by shear and concentration banding at the polar/isotropic interface. A further increment in the active forcing leads to the self-assembly of a soft channel where an isotropic fluid flows between two layers of active material. We characterize the stability of this state by performing a dynamical test varying the intensity of the active forcing and shear rate. Finally, we address the rheological properties of the system by measuring the effective shear viscosity, finding that this increases as active forcing is increased-so that the fluid thickens with activity.

6.
Sci Rep ; 9(1): 2801, 2019 Feb 26.
Artículo en Inglés | MEDLINE | ID: mdl-30808917

RESUMEN

We study numerically the behaviour of a two-dimensional mixture of a passive isotropic fluid and an active polar gel, in the presence of a surfactant favouring emulsification. Focussing on parameters for which the underlying free energy favours the lamellar phase in the passive limit, we show that the interplay between nonequilibrium and thermodynamic forces creates a range of multifarious exotic emulsions. When the active component is contractile (e.g., an actomyosin solution), moderate activity enhances the efficiency of lamellar ordering, whereas strong activity favours the creation of passive droplets within an active matrix. For extensile activity (occurring, e.g., in microtubule-motor suspensions), instead, we observe an emulsion of spontaneously rotating droplets of different size. By tuning the overall composition, we can create high internal phase emulsions, which undergo sudden phase inversion when activity is switched off. Therefore, we find that activity provides a single control parameter to design composite materials with a strikingly rich range of morphologies.

7.
J Clin Endocrinol Metab ; 67(6): 1317-21, 1988 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-3192685

RESUMEN

Anti-hCG/LH autoantibodies were found in the serum of an infertile woman a few days after an abortion which occurred after 46 days of amenorrhea. The antibody titer increased for approximately 4 more weeks, and then declined to low levels during a 14-month anovulatory period, after which regular menses resumed. Immunoglobulins isolated from a pool of serum obtained during the postabortion period neutralized the activity of both hCG and LH in an in vivo bioassay, and the binding affinity of the antibodies toward both hormones was high. When menses were resumed, there was a considerable reduction of the affinity toward LH. The variations in antibody titers and/or affinities can explain the sequence of fertilization, abortion, anovulatory period, and normalization of menses.


Asunto(s)
Aborto Espontáneo/inmunología , Amenorrea/inmunología , Autoanticuerpos/fisiología , Gonadotropina Coriónica/inmunología , Hormona Luteinizante/inmunología , Adulto , Afinidad de Anticuerpos , Autoanticuerpos/metabolismo , Femenino , Humanos , Pruebas de Neutralización , Embarazo
8.
J Endocrinol ; 91(2): 179-88, 1981 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-6795294

RESUMEN

Ultrafiltration of human sera resulted in increased levels of human chorionic gonadotrophin (hCH), LH and FSH measured by radioimmunoassay. The effect was greatly enhanced by chromatography of serum through Sepharose-protein A (which specifically binds immunoglobulin G) followed by ultrafiltration of the unretarded fractions. Serum from a normally menstruating women was treated by ultrafiltration and the retained fraction from 200 mul serum further chromatographed on a Sephadex G-150 Superfine column. The amounts of LH and FSH measured in the eluate by radioimmunoassay were higher by three orders of magnitude than those found in the untreated serum. Comparable amounts of hCG were also found in the eluate by two specific radioimmunoassays, and a value of 45 i.u. hCG was recovered in the eluate by bioassay. Serum from another normally menstruating women was applied to DEAE-cellulose and eluted stepwise using an elution gradient. The ultrafiltrate of one eluted fraction led to separation of a low molecular weight material which was able to neutralize the biological activity of a large dose of hCG. The data support the hypothesis that substantial amounts of gonadotrophins are normally present in serum but that binding to inhibitor(s) prevents their assay in untreated sera.


Asunto(s)
Gonadotropina Coriónica/sangre , Hormona Folículo Estimulante/sangre , Hormona Luteinizante/sangre , Bioensayo , Cromatografía en Gel , Femenino , Humanos , Masculino , Menstruación , Radioinmunoensayo , Ensayo de Unión Radioligante , Ultrafiltración
9.
Ann N Y Acad Sci ; 586: 218-29, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2357003

RESUMEN

In our study we have examined 314 samples of cyst fluid taken from women suffering from fibrocystic breast disease (gross cystic disease). We have subdivided the cyst fluid with respect to epithelial coating and we have related trophoblastic protein content of the cyst fluid with age, seriousness of illness, and cytology of epithelial lining. We have performed RIA analysis of the trophoblastic proteins betahCG, beta1-SP-1, and alphahCG and in a smaller (n=84) group of specimens we have also tested for CEA, TPA, and ferritin. Trophoblastic proteins were positive in cystic fluids but the biological meaning of this is not known and the values are not related to clinical manifestations, except in a group of patients with apocrine metaplasia in which we tried to find a relationship between fertile age and increased betahCG. This finding presumably has a prognostic meaning that can be further understood by epidemiologic studies (of dietary intake and evaluation of lipid metabolites) and by information about inflammatory state of cystic fluid.


Asunto(s)
Biomarcadores de Tumor/análisis , Gonadotropina Coriónica/análisis , Exudados y Transudados/análisis , Enfermedad Fibroquística de la Mama/análisis , Proteínas Gestacionales/análisis , Glicoproteínas beta 1 Específicas del Embarazo/análisis , Adulto , Factores de Edad , Neoplasias de la Mama/análisis , Femenino , Enfermedad Fibroquística de la Mama/patología , Humanos , Persona de Mediana Edad , Trofoblastos/análisis
10.
Clin Chim Acta ; 168(1): 33-46, 1987 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-3499261

RESUMEN

Pregnancy-specific beta 1 glycoprotein (SP1-beta) was purified from human retroplacental blood by sequential anion exchange chromatography, gel chromatography and affinity chromatography. The final preparation appeared to be electrophoretically and immunochemically pure and was in particular free from any component with alpha mobility. The preparation was used as immunogen in rabbits as well as tracer and standard for radioimmunoassay and for cross- and rocket-immunoelectrophoresis. It was shown that this radioimmunoassay procedure, allowed quantitative determination of SP1-beta glycoprotein without interference by the alpha component.


Asunto(s)
Proteínas Gestacionales/aislamiento & purificación , Glicoproteínas beta 1 Específicas del Embarazo/aislamiento & purificación , Electroforesis en Gel de Poliacrilamida , Femenino , Humanos , Inmunoensayo , Inmunoelectroforesis Bidimensional , Radioisótopos de Yodo , Focalización Isoeléctrica , Embarazo , Glicoproteínas beta 1 Específicas del Embarazo/inmunología , Radioinmunoensayo
11.
Contraception ; 21(3): 311-7, 1980 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-6771092

RESUMEN

Twelve subjects using the intrauterine progesterone system were followed during 4 consecutive menstrual cycles for FSH, LH, hCG and progesterone levels. They were all multiparous, with documented ovulation and sexually active even during the ovulatory period. With the exception of one case which became pregnant, there was no evidence for the presence of hCG during the period of observation. This data, even if preliminary, suggest that the Progestasert(TM) exerts a contraceptive action which differs from that of other devices, whether medicated or not, and that, such action occurs at a stage early enough to prevent the formation of hCG.


PIP: This study measured levels of human chorionic gonadotropin (hCG) in women using a Progestasert IUD system to determine the IUD mode of action. Though it is known that this IUD system acts locally, the mechanism of the local action was not known. 12 volunteers (aged 25-35 years and multiparous) who were sexually active were admitted to the study. Hormonal profiles were routinely obtained after IUD insertion. During the observation period, all subjects showed ovulatory levels of luteinizing hormone and follicle stimulating hormone peaks followed by increased progesterone levels. 11 of 12 cases showed no evidence of hCG. The 12th subject, who was diagnosed as pregnant subsequently, showed detectable levels of hCG on Day 25 of the cycle. Apparently, unlike other IUDs, medicated or not, this system acts locally before implantation, for hCG becomes measureable 6-7 days after fertilization.


Asunto(s)
Gonadotropina Coriónica/antagonistas & inhibidores , Dispositivos Intrauterinos Medicados , Progesterona/farmacología , Adulto , Gonadotropina Coriónica/sangre , Femenino , Hormona Folículo Estimulante/sangre , Humanos , Hormona Luteinizante/sangre , Progesterona/sangre
12.
Eur J Gynaecol Oncol ; 11(2): 91-6, 1990.
Artículo en Inglés | MEDLINE | ID: mdl-2379519

RESUMEN

Fourteen samples of epithelial ovarian cancer were studied; chemosensitivity in vitro was examined by clonogenic assay, and DNA content was measured by static cytometry. Seven cases were aneuploid. The average survival of the diploid cases was almost twice that of the aneuploid cases (21 vs 11 months). Five of the 7 diploid, and 4 of the aneuploid cases were chemosensitive in vitro; 4 diploid and 3 aneuploid tumors were sensitive in vivo. The vitro/vivo correlation was positive for 6 out of 7 aneuploid tumors, and for 4 out of 7 diploid cases. Patients sensitive in vitro to at least one of the two drugs tested responded more often to chemotherapy, whatever drugs were used in vitro. The patients whose 5 C exceeding rate was 10% survived 12 months at most, with an average survival of 8 months; patients with a low aneuploidy index survived an average of 20 months. The behavior of the diploid tumors in vitro was more varied. Ploidy would seem to be an additional factor to other parameters of prognosis, while no correlation is evident between chemosensitivity in vitro, D.I., and 5 C exceeding rate.


Asunto(s)
Ensayo de Unidades Formadoras de Colonias , Neoplasias Ováricas/tratamiento farmacológico , Ploidias , Ensayo de Tumor de Célula Madre , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/genética , Anciano , Doxorrubicina/farmacología , Femenino , Fluorouracilo/farmacología , Ácido Fólico/farmacología , Humanos , Técnicas In Vitro , Persona de Mediana Edad , Pronóstico
13.
Eur J Gynaecol Oncol ; 9(5): 414-9, 1988.
Artículo en Inglés | MEDLINE | ID: mdl-3224612

RESUMEN

The Authors have investigated preneoplastic lesions and the problem of the identification of benign lesions considered with or without preneoplastic potential, comparing for the occasion the presence of transformation markers in these lesions with the positivity of tumor markers in neoplastic tissue. The dosages have been valued on neoplastic tissue (180 cases), dysplastic tissue (50 cases), on cystic fluid (70 cases), and on nipple discharge (80 cases). The data obtained show a marked positivity to the tumor markers and the ionic and hormonal content (K+, Na+ DHEAS, PRL evaluation). The positivity of some lesions, not properly preneoplastic (or atypical) towards some markers of neoplasia could show some differences of great interest between benignity and malignity.


Asunto(s)
Neoplasias de la Mama/patología , Lesiones Precancerosas/patología , Biomarcadores de Tumor/análisis , Neoplasias de la Mama/metabolismo , Transformación Celular Neoplásica/patología , Femenino , Humanos , Lesiones Precancerosas/metabolismo , Pronóstico
14.
Eur J Gynaecol Oncol ; 13(1): 53-9, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1547794

RESUMEN

We have detected the expression of the MYB proto-oncogene in ovarian cancer. This oncogene was thought to be expressed in a tissue-specific manner in cells of hematopoietic lineage. Total RNA from three established cell lines and four human primary ovary cancers was examined by Northern and Southern blot, RNAse protection, in situ hybridization and cytogenetic analysis. A 3.8 kb RNA transcript was present in one human primary cell culture which is the same size as that found in the immature myeloid HL60 cell line. No expression was detected in normal ovary tissue. Southern blot analysis of DNA from five ovarian tumors indicated that this gene is not rearranged. Chromosomal analysis of three samples show many abnormalities in two cases and a normal karyotype in another one. The presence of MYB transcript in ovarian cancer suggests that MYB may play a specific role in the pathogenesis of this disease.


Asunto(s)
Regulación Neoplásica de la Expresión Génica/genética , Neoplasias Ováricas/genética , Proto-Oncogenes , ARN Mensajero/análisis , ARN Neoplásico/análisis , Northern Blotting , Southern Blotting , Femenino , Humanos , Proto-Oncogenes Mas
15.
Minerva Ginecol ; 44(5): 209-26, 1992 May.
Artículo en Italiano | MEDLINE | ID: mdl-1319010

RESUMEN

Fourteen patients (mean age 37 years) suffering from viral and/or intraepithelial cervico-vagino-vulvar pathologies underwent colposcopic and cyto-histological tests and molecular hybridization. The following types of HPV were assayed: 6/11-16/18-31/35/51 in cytological tissues (exocervical scraping) and biopsy material immersed in paraffin and fixed in formalin buffered with 10% PBS. The aim of the study was to identify different types of HPV using molecular hybridisation in situ. The paper reports the results and correlations with colposcopic, cytological and histological diagnosis, and then discuss the clinico-biological and prognostic aspects of this method.


Asunto(s)
Enfermedades de los Genitales Femeninos/diagnóstico , Neoplasias de los Genitales Femeninos/diagnóstico , Adulto , Condiloma Acuminado/diagnóstico , Condiloma Acuminado/microbiología , Condiloma Acuminado/patología , Femenino , Enfermedades de los Genitales Femeninos/microbiología , Enfermedades de los Genitales Femeninos/patología , Neoplasias de los Genitales Femeninos/patología , Humanos , Hibridación de Ácido Nucleico , Papillomaviridae/aislamiento & purificación , Infecciones Tumorales por Virus/diagnóstico , Infecciones Tumorales por Virus/microbiología , Infecciones Tumorales por Virus/patología , Frotis Vaginal
16.
Clin Exp Obstet Gynecol ; 16(1): 44-7, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2713993

RESUMEN

In the laser surgery service of the 2nd Department of the Obstetric and Gynecologic Clinic of the University of Rome "La Sapienza", from October 1984 to March 1987, we have treated with CO2 laser surgery (vaporization and conization) 228 patients affected with cervical lesions (HPV +/- CIN). The choice of the treatment must be based on two parameters: site and extension of the lesion. The results we have obtained with CO2 laser vaporization (201 cases) are most satisfactory (92%); patients have been followed-up from two to twenty-six months. As far as the CO2 laser conization is concerned (27 cases), patients were followed-up from two to twenty-two months and the percentage of success was 96.1%. The Authors evaluated also the side effects of the CO2 laser surgery.


Asunto(s)
Terapia por Láser , Displasia del Cuello del Útero/cirugía , Neoplasias del Cuello Uterino/cirugía , Adulto , Femenino , Humanos
17.
Clin Exp Obstet Gynecol ; 18(4): 207-13, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1790601

RESUMEN

During a six-month randomized study involving 460 post-menopausal women, transdermal estradiol has proved to be as effective as oral conjugated equine estrogens in the control of menopausal symptoms and to produce similar estrogenic effects on the endometrium. The group of patients treated with transdermal estradiol showed better compliance and had fewer drop-outs. Moreover, the quality and duration of menstrual bleeding were considered more physiological in the transdermal estradiol group than in the orally treated patients. The trial was carried out with the co-operation of 17 Italian University Centres, under the supervision of Ciba-Geigy Italy S.p.A. Medical Department.


Asunto(s)
Estradiol/administración & dosificación , Terapia de Reemplazo de Estrógeno , Estrógenos/administración & dosificación , Menopausia , Administración Cutánea , Administración Oral , Estradiol/sangre , Estrógenos/sangre , Femenino , Humanos , Menopausia/sangre , Menopausia/efectos de los fármacos , Persona de Mediana Edad
18.
Recenti Prog Med ; 80(11): 607-14, 1989 Nov.
Artículo en Italiano | MEDLINE | ID: mdl-2696020

RESUMEN

A randomized polycentric study was programmed to establish the effects of daily administration of ferritin iron from early pregnancy to puerperium. 254 women with normal iron balance at the beginning of their pregnancy were randomized receiving no supplements or 40 mg iron daily. At the end of pregnancy iron balance was still normal only in one third of the pregnant women of the first group versus two third of the second group. 204 women who were iron-deficient received daily 40 or 120 mg of iron; in this group anemia developed less frequently (13% versus 29%) and iron balance normalized in one subject on four; the great majority of these women remained iron-deficient. Unwanted effects of minimal or mild relevance, and almost always sporadic were observed in 6.5% of cases and with the reduction or withdraw of the treatment in only 1.4% of cases. These results showed that daily administration of ferritin iron during pregnancy is effective and well tolerated; furthermore they suggest that the treatment must be done with at least 60 mg daily in women with normal iron balance and protracted also after the puerperium in iron deficient subjects.


Asunto(s)
Anemia Hipocrómica/tratamiento farmacológico , Ferritinas/uso terapéutico , Deficiencias de Hierro , Anemia Hipocrómica/sangre , Evaluación de Medicamentos , Femenino , Ferritinas/administración & dosificación , Humanos , Hierro/sangre , Estudios Multicéntricos como Asunto , Embarazo , Estudios Prospectivos , Distribución Aleatoria
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