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1.
Nat Nanotechnol ; 15(2): 111-117, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31988509

RESUMO

Current-induced spin-transfer torques (STT) and spin-orbit torques (SOT) enable the electrical switching of magnetic tunnel junctions (MTJs) in non-volatile magnetic random access memories. To develop faster memory devices, an improvement in the timescales that underlie the current-driven magnetization dynamics is required. Here we report all-electrical time-resolved measurements of magnetization reversal driven by SOT in a three-terminal MTJ device. Single-shot measurements of the MTJ resistance during current injection reveal that SOT switching involves a stochastic two-step process that consists of a domain nucleation time and propagation time, which have different genesis, timescales and statistical distributions compared to STT switching. We further show that the combination of SOT, STT and the voltage control of magnetic anisotropy leads to reproducible subnanosecond switching with the spread of the cumulative switching time smaller than 0.2 ns. Our measurements unravel the combined impact of SOT, STT and the voltage control of magnetic anisotropy in determining the switching speed and efficiency of MTJ devices.

2.
Nat Nanotechnol ; 12(10): 980-986, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28825713

RESUMO

Current-induced spin-orbit torques are one of the most effective ways to manipulate the magnetization in spintronic devices, and hold promise for fast switching applications in non-volatile memory and logic units. Here, we report the direct observation of spin-orbit-torque-driven magnetization dynamics in Pt/Co/AlOx dots during current pulse injection. Time-resolved X-ray images with 25 nm spatial and 100 ps temporal resolution reveal that switching is achieved within the duration of a subnanosecond current pulse by the fast nucleation of an inverted domain at the edge of the dot and propagation of a tilted domain wall across the dot. The nucleation point is deterministic and alternates between the four dot quadrants depending on the sign of the magnetization, current and external field. Our measurements reveal how the magnetic symmetry is broken by the concerted action of the damping-like and field-like spin-orbit torques and the Dzyaloshinskii-Moriya interaction, and show that reproducible switching events can be obtained for over 1012 reversal cycles.

3.
Eur J Obstet Gynecol Reprod Biol ; 203: 82-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27261817

RESUMO

OBJECTIVE: To prove the efficacy, tolerability and safety of Monurelle Biogel(®) (ZP-025) vaginal gel, which contains a purified, dialyzed, lyophilized bovine colostrum, in women of reproductive age suffering from vaginal dryness. DESIGN: Randomized clinical trial (RCT) (Z7213M01). SETTING: Five University Gynaecological Units. PATIENTS: Ninety-five subjects were allocated at random to receive either ZP-025 (n=48) for about 23 intermenstrual days (1 or 2 times/daily intra-vaginally) or no treatment (lubricants on demand were allowed). MAIN OUTCOME MEASURES: Change of Verbal Rating Scale (VRS) total and single score for vaginal symptoms, Vaginal Health Index (VHI) score, Female Sexual Function index (FSFI) and Female Sexual Distress Scale-revised (FSDS-R) scores. RESULTS: A total number of 85 subjects was evaluable for primary analyses. Symptoms (VRS) of vaginal discomfort improved significantly already after 11 days, as compared to the control arm (p<0.0001). The mean VHI score was also significantly higher in ZP-025 group (p<0.001) at the end of the study. The analysis of covariance with the baseline value as covariate carried out on the FSFI Total Score showed a statistically significant difference in favour of the ZP-025 arm (p<0.032). A shift from presence to absence of sexual distress (≤11 points) was more prominent in the ZP-025 arm [10 subjects (40%) in the ZP-025 arm (p<0.0001) and 6 subjects (21.4%) in the control arm (p=0.01)]. Women reported a compliance rate of 100% for one ZP-025 application/day. Local tolerability of ZP-025 was excellent or good in 82.9% of the subjects. CONCLUSIONS: The present multicentre RCT supports the use of Monurelle Biogel(®) in women of reproductive age reporting symptoms of vaginal dryness. A positive impact on vaginal health and sexual function was also evident.


Assuntos
Libido/efeitos dos fármacos , Cremes, Espumas e Géis Vaginais/uso terapêutico , Doenças Vaginais/tratamento farmacológico , Administração Intravaginal , Adulto , Colostro , Feminino , Humanos , Pessoa de Meia-Idade , Comportamento Sexual/efeitos dos fármacos , Resultado do Tratamento , Cremes, Espumas e Géis Vaginais/farmacologia , Adulto Jovem
4.
Sci Rep ; 6: 26849, 2016 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-27241747

RESUMO

The self-synchronization of spin torque oscillators is investigated experimentally by re-injecting its radiofrequency (rf) current after a certain delay time. We demonstrate that the integrated power and spectral linewidth are improved for optimal delays. Moreover by varying the phase difference between the emitted power and the re-injected one, we find a clear oscillatory dependence on the phase difference with a 2π periodicity of the frequency of the oscillator as well as its power and linewidth. Such periodical behavior within the self-injection regime is well described by the general model of nonlinear auto-oscillators including not only a delayed rf current but also all spin torque forces responsible for the self-synchronization. Our results reveal new approaches for controlling the non-autonomous dynamics of spin torque oscillators, a key issue for rf spintronics applications as well as for the development of neuro-inspired spin-torque oscillators based devices.

5.
Fertil Steril ; 81(6): 1632-7, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15193487

RESUMO

OBJECTIVE: To assess the value of endometrial thickness as a marker of endometrial abnormality risk during hormone therapy (HT) and to study the correlation between abnormal bleeding and abnormal endometrial histology in patients with thick endometrium. DESIGN: Prospective multicenter study. SETTING: University and general hospitals outpatient centers. PATIENT(S): Postmenopausal women (702) on HT. INTERVENTION(S): Biendometrial thickness was measured by transvaginal sonography (TVS) between day 5 and day 10 after the last P intake and, when present, after the end of the menstrual-like bleeding. MAIN OUTCOME MEASURE(S): Hysteroscopy and biopsy were performed within 5 days from TVS on all patients with an endometrial thickness >4.5 mm (precision scale 0.5 mm). RESULT(S): Endometrial thickness >4.5 mm was observed in 20.5% of patients. One hundred sixteen hysteroscopies and biopsies were performed. Hyperplasia, polyps, and endocavitary fibroids were detected in 15%, 24%, and 8% of cases, respectively. The positive predictive value of TVS examination was 47%. Endometrial thickness was the only variable significantly and independently associated with histologic abnormalities and endocavitary fibroids. Abnormal bleeding occurred in 17.1% of patients. Among 17 patients detected with thick endometrium and hyperplasia, 8 cases showed abnormal bleeding. CONCLUSION(S): Sonographic endometrial thickness of 4.5 mm provides a sensitive tool to select HT patients who might benefit from hysteroscopy and biopsy. Abnormal bleeding is not a sensitive sign of hyperplasia in patients with thick endometrium.


Assuntos
Endométrio/diagnóstico por imagem , Terapia de Reposição Hormonal/efeitos adversos , Doenças Uterinas/induzido quimicamente , Doenças Uterinas/diagnóstico por imagem , Biópsia , Estudos Transversais , Endométrio/patologia , Feminino , Humanos , Histeroscopia , Valor Preditivo dos Testes , Estudos Prospectivos , Fatores de Risco , Ultrassonografia , Doenças Uterinas/patologia , Hemorragia Uterina/induzido quimicamente , Hemorragia Uterina/diagnóstico por imagem , Hemorragia Uterina/patologia
6.
Obstet Gynecol ; 103(4): 669-73, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15051557

RESUMO

OBJECTIVE: To evaluate the effect of mediolateral episiotomy on puerperal pelvic floor strength and dysfunction (urinary and anal incontinence, genital prolapse). METHODS: Five hundred nineteen primiparous women were enrolled 3 months after vaginal delivery. Puerperae were divided in 2 groups: group A (254 women) comprised the women who received mediolateral episiotomy and group B (265 women) the women with intact perineum and first- and second-degree spontaneous perineal lacerations. Each woman was questioned about urogynecological symptoms and examined by digital test, vaginal perineometry, and uroflowmetric stop test score. Data were subjected to Student t test and Fisher exact test to assess, respectively, the difference between the mean values and the proportions within the subpopulations. Using a simple logistic regression model to test an estimate of relative risk, we expressed the odds ratios of the variables considered with respect to the control population (group B). RESULTS: No significant difference was found with regard to the incidence of urinary and anal incontinence and genital prolapse, whereas dyspareunia and perineal pain were significantly higher in the episiotomy group (7.9% versus 3.4%, P =.026; 6.7% versus 2.3%, P =.014, respectively). Episiotomy was associated with significantly lower values, both in digital test (2.2 versus 2.6; P <.001) and in vaginal manometry (12.2 versus 13.8 cm water; P <.001), but not in uroflowmetric stop test. CONCLUSION: Mediolateral episiotomy does not protect against urinary and anal incontinence and genital prolapse and is associated with a lower pelvic floor muscle strength compared with spontaneous perineal lacerations and with more dyspareunia and perineal pain. LEVEL OF EVIDENCE: II-2


Assuntos
Episiotomia/efeitos adversos , Incontinência Fecal/etiologia , Diafragma da Pelve/fisiopatologia , Transtornos Puerperais/etiologia , Incontinência Urinária/etiologia , Prolapso Uterino/etiologia , Adulto , Dispareunia/etiologia , Feminino , Seguimentos , Humanos , Medição da Dor , Dor Pós-Operatória/etiologia
7.
Am J Obstet Gynecol ; 189(3): 894, 2003 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-14526341

RESUMO

We report the successful treatment with tibolone of a postmenopausal woman affected by primary Sjögren's syndrome. One year after the beginning of treatment, the woman does not need artificial tears and vaginal lubricants. This is the first report of an effective pharmacologic treatment for primary Sjögren's syndrome in humans.


Assuntos
Norpregnenos/uso terapêutico , Síndrome de Sjogren/tratamento farmacológico , Moduladores de Receptor Estrogênico/uso terapêutico , Feminino , Humanos , Pessoa de Meia-Idade , Pós-Menopausa
8.
J Reprod Med ; 48(3): 171-4, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12698774

RESUMO

OBJECTIVE: To evaluate the efficacy of different tests in identifying pelvic floor dysfunction after vaginal delivery. STUDY DESIGN: One hundred ninety-seven primiparae were investigated 2 months after vaginal delivery. They underwent pelvic floor muscle assessment by digital test, vaginal manometry and uroflowmetric stop test. Puerperae were divided into continent and incontinent subpopulations. Variables were subjected to Student's t test and Fisher's exact test to verify the difference between the subpopulations. Kappa values were used to correlate the tests. RESULTS: Perineal performance in incontinent primiparae was weaker in all the tests; only the urine stream interruption test score showed significantly different values (P = .0026), but it did not correlate with the other two tests. CONCLUSION: A simple, objective, noninvasive and low-cost technique, such as the urine stream interruption test, is useful in assessing pelvic floor performance after vaginal delivery but reflects urethrovesical support function rather than pelvic muscle function in toto.


Assuntos
Parto Obstétrico/efeitos adversos , Manometria , Doenças Musculares/diagnóstico , Doenças Musculares/fisiopatologia , Complicações do Trabalho de Parto/diagnóstico , Complicações do Trabalho de Parto/fisiopatologia , Palpação , Diafragma da Pelve/fisiopatologia , Reologia , Incontinência Urinária por Estresse/diagnóstico , Incontinência Urinária por Estresse/fisiopatologia , Urodinâmica/fisiologia , Adulto , Feminino , Humanos , Contração Muscular/fisiologia , Doenças Musculares/etiologia , Complicações do Trabalho de Parto/etiologia , Gravidez , Reprodutibilidade dos Testes , Incontinência Urinária por Estresse/etiologia , Vagina/fisiopatologia
9.
Acta Obstet Gynecol Scand ; 82(2): 143-6, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12648176

RESUMO

BACKGROUND: Aims of this study were to determine the rate of symptoms related to perineal trauma (anal and stress urinary incontinence) and to assess pelvic floor muscle function in women who underwent epidural analgesia. METHODS: Comparative design comprising 70 matched pairs of primiparous mothers. Each woman was questioned about urogynecologic symptoms and examined by digital test, vaginal perineometry and uroflowmetric stop test score 3 months after vaginal delivery. Urogenital prolapse was defined in accordance with the Baden and Walker's 'Halfway System Classification'. Statistical analysis was performed using Fisher's exact test to compare the two groups and simple logistic regression models to estimate the odds ratios of every variable considered in respect of the control population. RESULTS: No significant difference was found in the incidence of stress urinary incontinence, anal incontinence and vaginal prolapse in the two study groups. No significant differences were found between the study groups with regard to the digital test, vaginal manometry and urine stream interruption test. CONCLUSIONS: Use of epidural analgesia is not associated with symptoms related to perineal trauma and pelvic floor muscle weakness.


Assuntos
Analgesia Epidural/métodos , Parto Obstétrico , Diafragma da Pelve/fisiopatologia , Analgesia Epidural/efeitos adversos , Estudos de Casos e Controles , Incontinência Fecal/diagnóstico , Incontinência Fecal/etiologia , Incontinência Fecal/fisiopatologia , Feminino , Humanos , Manometria , Períneo/lesões , Períneo/fisiologia , Gravidez , Incontinência Urinária/diagnóstico , Incontinência Urinária/etiologia , Incontinência Urinária/fisiopatologia , Prolapso Uterino/diagnóstico , Prolapso Uterino/etiologia , Prolapso Uterino/fisiopatologia , Vagina
10.
Menopause ; 10(1): 53-7, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12544677

RESUMO

OBJECTIVE: To assess the effects of hormone replacement therapy (HRT) on visual function after menopause. DESIGN: This study was conducted on 80 postmenopausal women aged 52 to 70 years. Women were randomly divided into two groups: 40 women were treated by oral HRT (equine conjugated estrogens 0.625 mg/day + dydrogesterone 5 mg/day in a continuous combined regimen), and 40 women were not treated with hormones (control group). Each woman underwent a contrast sensitivity test, a Schirmer test, and an evaluation of intraocular pressure before starting the study and 1 year after the beginning of the study. Statistical analysis was performed by Student's test and Fisher's exact test. RESULTS: Contrast sensitivity function was significantly improved in all spatial frequencies (1.5, 3, 6, and 12 cycles per degree) with the exception of 18 cycles per degree in the HRT group 1 year after the beginning of treatment, whereas the control group demonstrated significant impairment at the lowest spatial frequencies (1.5, 3, and 6 cycles per degree). Tear production was significantly improved in the HRT group 1 year after the beginning of treatment, and intraocular pressure was similar in the two groups before and after the beginning of the study. CONCLUSIONS: HRT improves visual function, promoting a better contrast sensitivity and a higher tear production, but does not modify intraocular pressure.


Assuntos
Sensibilidades de Contraste/efeitos dos fármacos , Terapia de Reposição de Estrogênios , Menopausa , Transtornos da Visão/prevenção & controle , Idoso , Didrogesterona/administração & dosagem , Estrogênios Conjugados (USP)/administração & dosagem , Feminino , Humanos , Pressão Intraocular/efeitos dos fármacos , Pessoa de Meia-Idade , Lágrimas/efeitos dos fármacos , Resultado do Tratamento
11.
J Reprod Med ; 47(8): 670-4, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12216435

RESUMO

OBJECTIVE: To verify the applicability and significance of testing with a cotton-tipped swab in postpartum evaluation. STUDY DESIGN: One hundred seventy-eight puerperas were examined two months after vaginal delivery and underwent testing with a cotton-tipped swab, digital test, vaginal manometry and uroflowmetric urine stream interruption test. Statistical analysis was performed using Student's t test to evaluate the difference between mean values of continent and incontinent puerperas and the Bravais-Pearson coefficient to test the correlation between all the tests used in the study. RESULTS: Incontinent puerperas and multiparas had significantly higher swab test values than did continent and primiparas, who demonstrated a swab test mean value of 39.5 degrees during the Valsalva maneuver. The sensitivity of the swab test for stress urinary incontinence was 82.5%, while its specificity and positive predictive value were, respectively, 31.1% and 25.8%. CONCLUSION: Perineal damage occurs not only in symptomatic puerperas but most women. The swab test was unable to assess stress urinary incontinence in postpartum women, also, and demonstrated only urethral hypermobility. The swab test in the puerperium does not add significant information about pelvic floor performance and should not be used routinely postpartum.


Assuntos
Fibra de Algodão , Diafragma da Pelve/fisiopatologia , Períneo/lesões , Períneo/fisiopatologia , Período Pós-Parto , Transtornos Puerperais/diagnóstico , Transtornos Puerperais/fisiopatologia , Incontinência Urinária por Estresse/diagnóstico , Incontinência Urinária por Estresse/fisiopatologia , Adulto , Feminino , Humanos , Trabalho de Parto , Gravidez , Transtornos Puerperais/etiologia , Recuperação de Função Fisiológica/fisiologia , Reprodutibilidade dos Testes , Fatores de Risco , Sensibilidade e Especificidade , Incontinência Urinária por Estresse/etiologia , Manobra de Valsalva
12.
BJOG ; 109(7): 821-7, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12135220

RESUMO

OBJECTIVES: 1. To assess the reproducibility of an electronic ultrasonographic technique for the measurement of urethral angulation; 2. to test the ability of measurement of the urethral angle and bladder neck mobility to predict genuine stress incontinence; 3. to compare ultrasound variables in stress incontinent women and in controls. DESIGN: Case-control study. POPULATION: Twenty-three incontinent women and 50 controls. METHODS: Electronic measurements of the distance between the bladder neck and the symphysis pubis, the bladder neck and the symphysis pubis line and the midline of the symphysis (alpha angle) and the angle between the proximal and distal urethra (beta angle) by means of perineal ultrasonography with a comfortably full bladder at rest, during the Valsalva manoeuvre and during maximal pelvic floor contraction. The same procedure was performed by a second investigator. Repeatability was evaluated by the technique described by Bland and Altman. Statistical analysis was performed using Student's t test and the two-tailed paired t test. MAIN OUTCOME MEASURES: To test the possible role of the urethral angle in maintaining female continence. RESULTS: Ultrasound analysis showed good repeatability between the two observers and is not influenced by vesical volume. Beta angle and urethrovesical mobility are inversely proportional, both in continent and in incontinent women. Urethral angle identifies genuine stress incontinence better than urethrovesical mobility (sensitivity 96% vs 87%; specificity 92% vs 68%; positive predictive value 85% vs 55%). There are significant differences in all ultrasound variables between incontinent women and continent controls. CONCLUSIONS: This study suggests a significant role of the urethral angle in maintaining female continence (in incontinent women it is lower at rest and lowers with straining). Measurement of the urethral angle can provide useful additional information to that provided by ultrasound evaluation of bladder neck mobility.


Assuntos
Uretra/diagnóstico por imagem , Bexiga Urinária/diagnóstico por imagem , Incontinência Urinária por Estresse/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Variações Dependentes do Observador , Curva ROC , Ultrassonografia , Incontinência Urinária por Estresse/fisiopatologia , Urodinâmica
13.
Obstet Gynecol ; 99(4): 581-4, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12039115

RESUMO

OBJECTIVE: To determine the relation between postpartum perineal trauma and the development of puerperal pelvic floor dysfunctions. METHODS: A prospective study was conducted on 218 primiparae immediately after vaginal delivery. Women were divided in three groups according to perineal trauma: group A (n = 171) intact perineum or superficial tear, group B (n = 39) perineal muscle tears, group C (n = 8) anal sphincter tears with or without disruption of the rectal mucosa. Two months later, each woman was questioned about urogynecologic symptoms and examined by digital test, vaginal perineometry, and uroflowmetric stop test score. RESULTS: No significant difference was found among the groups with regard to the incidence of stress incontinence, frequency/urgency, and urge incontinence, whereas anal incontinence was found more commonly in group C (group C versus group A: P =.003, odds ratio 18.78). No significant difference was found for digital test, perineometry, and uroflowmetric stop test. CONCLUSION: Immediate postpartum perineal examination is not a good predictor of stress incontinence and pelvic floor weakness but could identify women at risk for anal dysfunctions: intact perineum does not exclude the appearance of symptoms related to perineal trauma after vaginal delivery.


Assuntos
Músculo Esquelético/lesões , Períneo/lesões , Exame Físico/efeitos adversos , Período Pós-Parto , Incontinência Urinária/etiologia , Adulto , Incontinência Fecal/diagnóstico , Incontinência Fecal/epidemiologia , Incontinência Fecal/etiologia , Feminino , Humanos , Incidência , Paridade , Diafragma da Pelve , Estudos Prospectivos , Incontinência Urinária/diagnóstico , Incontinência Urinária/epidemiologia , Incontinência Urinária por Estresse/diagnóstico , Incontinência Urinária por Estresse/epidemiologia , Incontinência Urinária por Estresse/etiologia , Urodinâmica
14.
Eur J Obstet Gynecol Reprod Biol ; 103(2): 179-82, 2002 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-12069744

RESUMO

OBJECTIVES: To assess the prevalence of urinary symptoms, the relationship between urinary symptoms and vaginal descent, and the association between urinary symptoms and obstetric factors. STUDY DESIGN: Five hundred and thirty-seven women were interviewed and underwent a urogynaecological evaluation 3 months after vaginal delivery. Quantitative-type variables were subjected to Student's t test. Simple logistic regression analyses were carried out on the symptoms studied as a function of risk factors. RESULTS: 8.2% of primiparae showed stress urinary incontinence and multiparae in 20% (P=0.0001); urge incontinence was present in 5.5% of primiparae and in 13% of multiparae (P=0.004). Significant correlations were found among operative vaginal delivery, dysuria (P=0.048) and frequency (P=0.036). Urinary incontinence appeared associated with induced labour with prostaglandins (P=0.018) and with general maternal factors, such as parity (P=0.001) and elevated weight at the beginning of pregnancy (P=0.019). CONCLUSIONS: It is likely that the pathogenesis of postpartum urinary incontinence includes not only the effects of pelvic floor trauma on urethrovesical mobility under stress, but also a deficiency in urethral resistance caused by drugs, such as prostaglandins.


Assuntos
Período Pós-Parto , Transtornos Urinários/epidemiologia , Adulto , Feminino , Humanos , Segunda Fase do Trabalho de Parto , Trabalho de Parto Induzido/efeitos adversos , Idade Materna , Paridade , Diafragma da Pelve/fisiopatologia , Gravidez , Prevalência , Análise de Regressão , Fatores de Risco , Incontinência Urinária/epidemiologia , Incontinência Urinária/etiologia , Transtornos Urinários/etiologia , Aumento de Peso
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