1,100 research outputs found
Propulsion system tests on a full scale Centaur vehicle to investigate 3-burn mission capability of the D-lT configuration
Propulsion system tests were conducted on a full scale Centaur vehicle to investigate system capability of the proposed D-lT configuration for a three-burn mission. This particular mission profile requires that the engines be capable of restarting and firing for a final maneuver after a 5-1/2-hour coast to synchronous orbit. The thermal conditioning requirements of the engine and propellant feed system components for engine start under these conditions were investigated. Performance data were also obtained on the D-lT type computer controlled propellant tank pressurization system. The test results demonstrated that the RL-10 engines on the Centaur vehicle could be started and run reliably after being thermally conditioned to predicted engine start conditions for a one, two and three burn mission. Investigation of the thermal margins also indicated that engine starts could be accomplished at the maximum predicted component temperature conditions with prestart durations less than planned for flight
Comparison of pelvic floor dysfunction 6 years after uncomplicated vaginal versus elective cesarean deliveries: a cross-sectional study.
Clinicians and patients have traditionally believed that elective cesarean section may protect against certain previously ineluctable consequences of labor, including a plethora of urinary, anorectal and sexual dysfunctions. We aimed to evaluate fecal, urinary and sexual symptoms 6 years postpartum, comparing uncomplicated vaginal delivery and elective cesarean delivery, and to assess their impact on quality of life. We conducted a cross-sectional study to compare perineal functional symptomatology between women having singleton elective cesarean deliveries (eCS) and singleton uncomplicated vaginal deliveries (uVD). Women who delivered 6 years before this study were chosen randomly from our hospital database. This database includes demographic, labor, and delivery information, as well as data regarding maternal and neonatal outcomes, all of which is collected at the time of delivery by the obstetrician. Four validated self-administrated questionnaires were sent by post to the participants: the short forms of the Urogenital Distress Inventory, Incontinence Impact Questionnaire, Wexner fecal incontinence scale, and Female Sexual Function Index. Current socio-demographic details, physical characteristics, obstetrical history and mode of delivery at subsequent births were also registered using a self-reported questionnaire. A total of 309 women with uVD and 208 with eCS returned postal questionnaires. The response rate was 49%. Socio-demographic characteristics and fecal incontinence were similar between groups. After eCS, women reported significantly less urgency urinary incontinence (adjusted Relative Risk 0.55; 95% confidence interval 0.34-0.88) and stress incontinence (adjusted Relative Risk 0.53; 95% confidence interval 0.35-0.80) than after uVD. No difference in total Incontinence Impact Questionnaire score was found between both modes of delivery. Lower abdominal or genital pain (adjusted Relative Risk 1.58; 95% confidence interval 1.01-2.49) and pain related to sexual activity (adjusted Relative Risk 2.50; 95% confidence interval 1.19-5.26) were significantly more frequent after eCS than uVD. Six years postpartum, uVD is associated with urinary incontinence, while eCS is associated with sexual and urination pain
Impact of the COVID-19 pandemic on Swiss pregnant and breastfeeding women - a cross-sectional study covering the first pandemic wave.
Information on the impact of the COVID-19 pandemic on pregnancy and breastfeeding experiences, as well as on perinatal mental health in Switzerland is limited. In Switzerland, there are few national studies and little information. Using an anonymous online survey accessible after the first wave of the outbreak in Switzerland, we have investigated how this pandemic affected pregnant and breastfeeding women. Among women who completed the survey, 69.0% (1050/1518) indicated the first wave of the pandemic affected their personal habits, 61.0% (689/1131) were affected in their work and 40.0% (632/1573) reported impaired relations with healthcare services (different denominators correspond to the number of participants who answered the question). 36.8% (110/299) of women reported an impact of the pandemic on their current pregnancy experience or breastfeeding experience (8.2%, 46/555). Overall, 11.6% (170/1467) of participants who completed the validated screening tests for mental health symptoms (Edinburgh Postnatal Depression Scale, Generalized Anxiety Disorder 7, Perceived Stress Scale) presented a score compatible with symptoms of major depression, severe anxiety or high perceived stress, which is higher than in the pre-pandemic period according to literature. Risk factors independently associated with impaired mental health were being hospitalized, having symptoms of COVID-19, living with a person with COVID-19 symptoms, having comorbidities, having experienced reduced healthcare services, having restricted usual activities and being a housewife. Protective factors independently associated were a high level of education and living with a partner. Our findings suggest that the COVID-19 pandemic might have significantly affected the well-being and mental health of pregnant and breastfeeding women, directly in the case of exposure, and indirectly as a result of the potential modifications in their life habits and in healthcare facilities
The K^{+}--->\pi^{+}\nu\bar{nu} Rare Decay in Two Higgs Doublet Model
The rare k+--->pi+ \nu \bar{\nu} decay is investigated in the context of type
II two-Higgs-doublet model (2HDM). By using the existing experimental data of
the branching ratio, restrictions on the free parameters of the model m_H, and
tan\beta are obtained: tan\beta belong to the range 0.7- o.8, and m_H belong to
the range 500- 700 GeV.Comment: 12 pages, latex file, 3 figures, postscript file
Fishpathogens.EU/NODA: A Free and Handy Online Platform for Betanodavirus Targeted Research and Data Sharing
On the difference between type E and A OH/IR stars
The observed SEDs of a sample of 60 OH/IR stars are fitted using a radiative
transfer model of a dusty envelope. Among the whole sample, 21 stars have
reliable phase-lag distances while the others have less accurate distances.
L*-P,Mlr-P and Mlr-L* relations have been plotted for these stars. It is found
that type E (with emission feature at 10um and type A (with absorption feature
at 10um) OH/IR stars have different L*-P and Mlr-L* relations while both of
them follow a single Mlr-P relation. The type E stars are proven to be located
in the area without large scale dense interstellar medium while the type A
stars are located probably in dense interstellar medium. It is argued here that
this may indicate the two types of OH/IR stars have different chemical
composition or zero age main sequence mass and so evolve in different ways.
This conclusion has reinforced the argument by Chen et al.(2001) who reached a
similar conclusion from the galactic distribution of about 1000 OH/IR stars
with the IRAS low-resolution spectra (LRS).Comment: 6 pages, 9 figures, 2 table
Sperm Microbiota and Its Impact on Semen Parameters
Compared to its female counterpart, the microbiota of the male genital tract has
not been studied extensively. With this study, we aimed to evaluate the bacterial
composition of seminal fluid and its impact on sperm parameters. We hypothesized
that a dysbiotic microbiota composition may have an influence on sperm quality.
Semen samples of 26 men with normal spermiogram and 68 men with at least one
abnormal spermiogram parameter were included in the study. Samples were stratified
based on total sperm count, spermatozoa concentration, progressive motility, total
motility and spermatozoa morphology. Microbiota profiling was performed using 16S
rRNA gene amplicons sequencing and total bacterial load was determined using a
panbacterial quantitative PCR. Semen samples broadly clustered into three microbiota
profiles: Prevotella-enriched, Lactobacillus-enriched, and polymicrobial. Prevotellaenriched samples had the highest bacterial load (p < 0.05). Network analysis identified
three main co-occurrence modules, among which two contained bacteria commonly
found in the vaginal flora. Genera from the same module displayed similar oxygen
requirements, arguing for the presence of different ecological niches for bacteria that
colonize semen through the passage. Contrary to our hypothesis, shifts in overall
microbiota composition (beta-diversity) did not correlate with spermiogram parameters.
Similarly, we did not find any difference in microbial richness or diversity (alphadiversity). Differential abundance testing, however, revealed three specific genera that
were significantly enriched or depleted in some of the sperm quality groups (p < 0.05).
Prevotella relative abundance was increased in samples with defective sperm motility
while Staphylococcus was increased in the corresponding control group. In addition,
we observed an increased relative abundance of Lactobacillus in samples with normal
sperm morphology. Our study indicates that overall bacterial content of sperm might not
play a major role in male infertility. Although no major shifts in microbiota composition or
diversity were found, the differential abundance of specific bacterial genera in the sperm
suggests that a small subset of microbes might impact the spermatozoal physiology
during sperm transition, more specifically motility and morphology. Further studies are
required to challenge this finding and develop potential strategies to induce the formation
of a healthy seminal microbiota
Reproductive Safety of Trazodone After Maternal Exposure in Early Pregnancy: A Comparative ENTIS Cohort Study.
Trazodone is indicated for the treatment of major depressive disorder, but more frequently prescribed off-label at lower doses for insomnia in women of childbearing age. The aim of this study was to assess the risks linked to trazodone exposure during pregnancy for which limited safety data are available.
This multicenter, observational prospective cohort study compared pregnancy outcomes in women exposed to trazodone in early pregnancy against those in a reference group of women exposed to a selective serotonin reuptake inhibitors (SSRIs) between 1996 and 2021.
The sample included 221 trazodone and 869 SSRI-exposed pregnancies. Exposure to trazodone in the first trimester was not associated with a significant difference in the risk of major congenital anomalies (trazodone [1/169, 0.6%]; SSRI [19/730, 2.6%]; adjusted odds ratio, 0.2; 95% confidence interval, 0.03-1.77). The cumulative incidences of live birth were 61% and 73% in the trazodone and reference group, respectively (25% vs 18% for pregnancy loss and 14% vs 10% for pregnancy termination). Trazodone exposure was not associated with a significantly increased risk of pregnancy termination and pregnancy loss. The rate of small for gestational age infants did not differ between the groups.
This study did not reveal a significant difference in the risk of major congenital anomalies after first trimester exposure to trazodone, compared with SSRI exposure. Although this study is the largest so far, these results call for confirmation through further studies
Computational exploration of molecular receptive fields in the olfactory bulb reveals a glomerulus-centric chemical map
© The Author(s) 2020. This article is licensed under a Creative Commons Attribution 4.0 International License. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.Progress in olfactory research is currently hampered by incomplete knowledge about chemical receptive ranges of primary receptors. Moreover, the chemical logic underlying the arrangement of computational units in the olfactory bulb has still not been resolved. We undertook a large-scale approach at characterising molecular receptive ranges (MRRs) of glomeruli in the dorsal olfactory bulb (dOB) innervated by the MOR18-2 olfactory receptor, also known as Olfr78, with human ortholog OR51E2. Guided by an iterative approach that combined biological screening and machine learning, we selected 214 odorants to characterise the response of MOR18-2 and its neighbouring glomeruli. We found that a combination of conventional physico-chemical and vibrational molecular descriptors performed best in predicting glomerular responses using nonlinear Support-Vector Regression. We also discovered several previously unknown odorants activating MOR18-2 glomeruli, and obtained detailed MRRs of MOR18-2 glomeruli and their neighbours. Our results confirm earlier findings that demonstrated tunotopy, that is, glomeruli with similar tuning curves tend to be located in spatial proximity in the dOB. In addition, our results indicate chemotopy, that is, a preference for glomeruli with similar physico-chemical MRR descriptions being located in spatial proximity. Together, these findings suggest the existence of a partial chemical map underlying glomerular arrangement in the dOB. Our methodology that combines machine learning and physiological measurements lights the way towards future high-throughput studies to deorphanise and characterise structure-activity relationships in olfaction.Peer reviewe
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