1,200 research outputs found

    The effect of radiotherapy on survival of dental implants in head and neck cancer patients

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    Objectives: To explore the current literature of the survival of dental implants in irradiated head and neck cancer patients considering the role of implant location, bone augmentation, dose of radiation and timing of implant placement. Study Design: Pubmed search was conducted to identify articles published between January 2000 and December 2014 and presenting data of dental implant survival with radiotherapy in head and neck cancer patients. Studies on animal subjects and craniofacial implants were excluded. Results: 18 articles out of 27 were eligible for inclusion in this systematic review. 12 out of 18 studies reported favorable outcome of dental implants and radiotherapy with survival rates between 74.4% and 97%. Seven out of ten studies comparing the survival rates according to site of implant placement reported that implants were found to osseointegrate with greater success in the irradiated mandible than irradiated maxilla. 5 studies which compared implant survival in irradiated native bone versus irradiated grafted bone reported that irradiated grafted bone showed a significantly reduced dental implant survival rate in comparison to irradiated native bone. 6 out of 18studies in which radiation doses exceeded 70 Gy reported lower survival rates of dental implants in comparison to the studies in which radiation doses were ≤70Gy. Higher survival rates were reported in 2 studies in which implants placement was before radiotherapy in comparison to the remaining 16 studies in which implants placement was after radiotherapy. Conclusions: Dental implants may be affected by radiotherapy especially when they are placed in maxilla, in grafted bone, or after radiation, however, they remain a functional option for rehabilitation of head and cancer patients. More prospective cohort studies and randomized controlled trails are still needed to draw more evidence based conclusion

    Predictors of Human Immunodeficiency Virus Knowledge among Jordanian Youths

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    Objectives: Understanding factors associated with the level of human immunodeficiency virus (HIV) knowledge acquisition is crucial to inform preventative programmes for young people. This study examines predictors of HIV knowledge among Jordanian youths. Methods: A cross-sectional survey was conducted among 8,129 youths aged between 14 and 25 years randomly selected from schools representing each of the 12 governorates of Jordan. A total of 50% of respondents were female and, on average, 17 years old. Participants completed a self-administered questionnaire covering sociodemographic characteristics, HIV knowledge, gender awareness, exposure to and favourable attitudes toward risky behaviours. Results: On a 13-item HIV knowledge test, participants answered an average of 7 questions correctly (mean = 7.21; standard deviation = 2.63). Female respondents from rural areas demonstrated significantly lower levels of HIV knowledge, while college and university students demonstrated higher levels. HIV knowledge differed significantly by sources of information, with peeracquired information associated with more accuracy, while HIV information from parents or health centres was associated with a lower score. Youths with more egalitarian gender views also demonstrated higher knowledge levels, whereas youths approving of drug use showed lower levels of HIV knowledge. Conclusion: HIV education programmes in Jordan should focus on females and youths living in rural areas. Educational institutions have been shown to be effective in providing accurate information to students, while parents and health professionals should also be included in HIV prevention programmes in order to reduce misconceptions and raise the level of HIV knowledge among Jordanian youths

    A Test of the Eikonal Approximation in High-Energy (e,e'p) Scattering

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    The Glauber method is extensively used to describe the motion of a hadronic projectile in interaction with the surrounding nuclear medium. One of the main approximations consists in the linearization of the wave equation for the interacting particle. We have studied the consequences of such an assumption in the case of the 12C(e,ep)11B^{12}\mathrm{C(e,e}'\mathrm{p)}^{11}\hbox{\rm B}^* reaction at high proton momenta by comparing the results with the predictions obtained when all the ingredients of the calculation are unchanged but the second-order differential equation for the scattered wave, which is solved exactly for each partial wave up to a maximum of 120 spherical harmonics. We find that the Glauber cross section is always larger by a factor 10÷20%10 \div 20 \%, even at vanishing missing momenta. We give a quantum-mechanical explanation of this discrepancy. Nevertheless, a good correlation is found between the two predictions as functions of the missing momentum, especially in parallel kinematics.Comment: LaTeX, 8 pages, 4 figures uuencoded, accepted for publication on Phys. Lett.

    Modal dependent type theory and dependent right adjoints

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    In recent years we have seen several new models of dependent type theory extended with some form of modal necessity operator, including nominal type theory, guarded and clocked type theory, and spatial and cohesive type theory. In this paper we study modal dependent type theory: dependent type theory with an operator satisfying (a dependent version of) the K-axiom of modal logic. We investigate both semantics and syntax. For the semantics, we introduce categories with families with a dependent right adjoint (CwDRA) and show that the examples above can be presented as such. Indeed, we show that any finite limit category with an adjunction of endofunctors gives rise to a CwDRA via the local universe construction. For the syntax, we introduce a dependently typed extension of Fitch-style modal lambda-calculus, show that it can be interpreted in any CwDRA, and build a term model. We extend the syntax and semantics with universes

    Chance of healthy versus adverse outcome in subsequent pregnancy after previous loss beyond 16 weeks: data from a specialized follow-up clinic

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    PURPOSE: Women with a previous fetal demise have a 2-20 fold increased risk of another stillbirth in a subsequent pregnancy when compared to those who have had a live birth. Despite this, there is limited research regarding the management and outcomes of subsequent pregnancies. This study was conducted to accurately quantify the chances of a woman having a healthy subsequent pregnancy after a pregnancy loss. METHODS: A retrospective study was conducted at a tertiary-level unit between March 2019 and April 2021. We collected data on all women with a history of previous fetal demise attending a specialized perinatal history clinic and compared the risk of subsequent stillbirth to those with a normal pregnancy outcome. Outcome data included birth outcome, obstetric and medical complications, gestational age and birth weight and mode of delivery. Those who had healthy subsequent pregnancies were compared with those who experienced adverse outcomes. RESULTS: A total of 101 cases were reviewed. Ninety-six women with subsequent pregnancies after a history of fetal demise from 16 weeks were included. Seventy-nine percent of women (n = 76) delivered a baby at term, without complications. Overall, 2.1% had repeat pregnancy losses (n = 2) and 2.1% delivered babies with fetal growth restriction (n = 2). There were no cases of abruption in a subsequent pregnancy. Eighteen neonates were delivered prematurely (18.4%), 15 of these (83.3%) were due to iatrogenic causes and three (16.7%) were spontaneous. In univariable logistic regression analyses, those with adverse outcomes in subsequent pregnancies had greater odds of pre-eclampsia (Odds ratio *(OR) = 3.89, 95% CI = 1.05-14.43, p = .042) and fetal growth restriction (OR = 4.58, 95% CI = 1.41-14.82, p = 0.011) in previous pregnancies compared to those with healthy outcomes. However, in multivariable logistic regression analyses, neither variable had a significant odds ratio (OR = 2.03, 95% CI = 0.44-9.39, p = .366 and OR = 3.42, 95% CI = 0.90 - 13.09, p = .072 for pre-eclampsia and FGR, respectively). CONCLUSION: Four in five women had a healthy subsequent pregnancy. This is a reassuring figure for women when contemplating another pregnancy, particularly if cared for in a specialist clinic

    Gene editing restores dystrophin expression in a canine model of Duchenne muscular dystrophy

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    Mutations in the gene encoding dystrophin, a protein that maintains muscle integrity and function, cause Duchenne muscular dystrophy (DMD). The deltaE50-MD dog model of DMD harbors a mutation corresponding to a mutational “hotspot” in the human DMD gene. We used adeno-associated viruses to deliver CRISPR gene editing components to four dogs and examined dystrophin protein expression 6 weeks after intramuscular delivery (n = 2) or 8 weeks after systemic delivery (n = 2). After systemic delivery in skeletal muscle, dystrophin was restored to levels ranging from 3 to 90% of normal, depending on muscle type. In cardiac muscle, dystrophin levels in the dog receiving the highest dose reached 92% of normal. The treated dogs also showed improved muscle histology. These large-animal data support the concept that, with further development, gene editing approaches may prove clinically useful for the treatment of DMD

    Lip and oral lesions in children with Down syndrome: a controlled study

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    Background: Down syndrome (DS) is the most common chromosomal abnormality affecting numerous organs, including the orofacial region. The objective of the present study was to assess the prevalence of lip and oral soft tissue lesions, with particular emphasize on the incidence of fissured tongue, lip fissures and angular cheilitis, among individuals with DS in Yemen. Material and Methods: This controlled cross-sectional study included 50 children with DS (6-18 years), and 50 age- and gender-matched healthy controls. The prevalence of orofacial soft tissue lesions was evaluated in both groups. Data were analyzed by Chi-square and Fisher tests, and p <0.05 was considered to be statistically significant. Results: Ten orolabial lesions were identified among the subjects. The most frequently seen lesions were: Fissured tongue (78.0%), lip fissures (64.0%), angular cheilitis (38.0%) and Cheilitis (14.0%). The frequencies of these lesions were significantly higher in children with DS than healthy controls ( P < 0.001). Most of lip fissures were in the lower lip, and 80% of the fissures were in the midline. Conclusions: The prevalence of lip and oral lesions among individuals with DS is remarkably high. Hence, oral physicians should be more aware of the orofacial findings seen more frequently in this genetic disorder

    Digital Single-Cell Analysis of Plant Organ Development Using 3DCellAtlas

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    Diverse molecular networks underlying plant growth and development are rapidly being uncovered. Integrating these data into the spatial and temporal context of dynamic organ growth remains a technical challenge. We developed 3DCellAtlas, an integrative computational pipeline that semiautomatically identifies cell types and quantifies both 3D cellular anisotropy and reporter abundance at single-cell resolution across whole plant organs. Cell identification is no less than 97.8% accurate and does not require transgenic lineage markers or reference atlases. Cell positions within organs are defined using an internal indexing system generating cellular level organ atlases where data from multiple samples can be integrated. Using this approach, we quantified the organ-wide cell-type-specific 3D cellular anisotropy driving Arabidopsis thaliana hypocotyl elongation. The impact ethylene has on hypocotyl 3D cell anisotropy identified the preferential growth of endodermis in response to this hormone. The spatiotemporal dynamics of the endogenous DELLA protein RGA, expansin gene EXPA3, and cell expansion was quantified within distinct cell types of Arabidopsis roots. A significant regulatory relationship between RGA, EXPA3, and growth was present in the epidermis and endodermis. The use of single-cell analyses of plant development enables the dynamics of diverse regulatory networks to be integrated with 3D organ growth

    Management and birth outcomes of pregnant women with Chiari malformations : a 14 years retrospective case series

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    Objective The management of Chiari malformations in pregnancy is challenging due to the perceived risk of adverse maternal neurological outcomes and raising intracranial pressure during labour. Our aim was to evaluate the management and health outcomes of pregnant women cared for at a regional referral center and highlight elements of best practice. Study Design A retrospective case series of all pregnant women diagnosed with Chiari malformation over fourteen years (January 2004- June 2018) at the Birmingham Women’s Hospital – UK. Results Twenty-one women (23 pregnancies) with Chiari malformation were included, four had syringomyelia (4/21,19%) and six had previously undergone craniovertebral decompression (6/21, 29%). The median age was 34-years (range 20-41), the median gravidity was two (range 1-8), the median parity was one (range 0-6), and the median extent of tonsillar herniation was 11 mm (range 9-18). The majority of women received their preferred mode of delivery (15 normal vaginal deliveries (15/23, 65.2%) and 6 elective Caesarean sections (6/23, 26.1%)) with two pregnancies ending with an emergency caesarean section for obstetric complications (2/23, 8.7%). Five Caesarean section were performed under general anaesthetic, two under spinal (2/23, 8.7%) and one under epidural anaesthesia (1/23, 4.3%) with no neurological sequelae. There were no adverse neurological outcomes at discharge postnatally. Conclusions Offering normal vaginal delivery with effective analgesia, for women with Chiari malformation, appears to be safe. Pregnancy care should be provided by a multi-disciplinary team with experience in managing Chiari malformation
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