Multigenerational Theoretical Study of Isoprene Peroxy Radical 1-5-Hydrogen Shift Reactions that Regenerate HO x Radicals and Produce Highly Oxidized Molecules.

A computational protocol is employed to glean new insight into the kinetics of several 1,5-hydrogen atom (H) shift reactions subsequent to first- and second-generation OH/O2 additions to isoprene. The M06-2X density functional was initially used with the Nudged Elastic Band (NEB) method to determine the potential energy surface of OH/O2 addition reactions, the 1,5-H shift reactions, and the fragmentation exit channels. The Master Equation Solver for Multi-Energy Well Reactions (MESMER) was applied to determine the rate constants for OH addition and the 1,5-H shifts. M06-2X was capable of quantifying the rate constants of OH addition to the first and second double bonds of isoprene with deviations less than 17% from the experimentally determined values. However, M06-2X underestimated the 1,5-H shift rate constants of second-generation isoprene peroxy radicals. Consequently, MN15, ωB97X-D, and CBS-QB3 methods were employed to compute average barrier heights to first- and second-generation 1,5-H shifts. In the first generation, the rate constants of H abstraction by ß-(1,2) and (4,3) isoprene hydroxy-peroxy radicals from the neighboring hydroxyl group are 1.1 × 10-3 and 2.4 × 10-3 s-1, respectively. These values are determined primarily by the barrier of the H shift reaction and, to a smaller albeit nonnegligible extent, by the stability of the resulting alkoxy radical and the exit barrier leading to C-C bond dissociation. In contrast, the average second-generation rate constant of 1,5-H shifts from H-R-OH sites to the peroxy radical is 1.8 × 10-1 s-1, with tunneling playing the significant role of increasing this value relative to first-generation 1,5-H shifts. Under low NO x conditions, first-generation isoprene oxidation reactions may recycle HO x at levels ranging from 10 to 30% due in large part to 1,5-H shifts, with the recycling efficiency being sensitive to HO2 concentrations and temperature. HO x recycling is expected to increase to levels beyond 80% in second-generation reactions of oxidized isoprene species because of isoprene epoxydiol (IEPOX) formation and further 1,5-H shifts that are kinetically favorable.

Improving number sense in kindergarten children with low achievement in mathematics / La mejora del sentido de número en niños de preescolar con bajo rendimiento en matemáticas

The present study evaluated the effectiveness of educational intervention software, Playing with Numbers-2 on early mathematics learning. This software trains learning and mathematical reasoning skills, using an evidenced-based procedure. A total of 156 second-year preschool boys and girls (Mean age = 65.39 months) were assessed by the Early Numeracy Test (ENT), a computerized test to evaluate early math competency. An experimental design with control group and pre and post-intervention assessments was used. Significant differences between pre- and post- intervention for the experimental group was obtained average increase for ENT scores achieved by the experimental group was significantly higher than the control group. The effect size was also significant (d = 1.35; and r = .56). This educational intervention using computer-based software, while it does not replace face-to-face instruction, may help to improve the performance of young students at risk of developing problems learning mathematics

El presente estudio evaluó la eficacia del programa de intervención educativa denominado Jugando con los números-2 en el aprendizaje matemático temprano. Este software incide en el aprendizaje y el perfeccionamiento de las habilidades de razonamiento matemático utilizando un procedimiento basado en la evidencia. Un total de 156 niños y niñas en edad preescolar (edad media = 65.39 meses) los cuales fueron evaluados mediante el instrumento Early Numeracy Test (ENT), un test computarizado para evaluar la competencia matemática temprana. Se utilizó un diseño experimental con grupo control y evaluaciones pre y post-intervención. Se obtuvieron diferencias significativas antes y después de la intervención para el grupo experimental mostrando un incremento en las puntuaciones arrojadas que fueron significativamente superiores a las alcanzadas por el grupo control. El tamaño del efecto fue también significativo (d = 1.35; y r = .56). Esta intervención educativa utilizando como base un programa computarizado no pretende reemplazar la instrucción tradicional, pero puede ayudar a mejorar el rendimiento de los estudiantes jóvenes en riesgo de desarrollar dificultades de aprendizaje de las matemáticas

The management of HIV in pregnancy: A 10-year experience.

OBJECTIVE: The package of care to reduce HIV mother to child transmission (MTCT) has evolved significantly since trials of ante and intrapartum antiretroviral therapy (ART) in 1994. In the UK MTCT rate has fallen from 25.6% in the 1990s to 0.46%. We review the management of HIV in pregnancy in Brighton in the context of evolving guidelines. STUDY DESIGN: HIV, obstetric and neonatal notes of all HIV positive women, pregnant between 2003 and 2014, were reviewed. RESULTS: 97 pregnancies in 75 women were identified, resulting in 79 live births. Antenatal HIV diagnosis was made in 22 (28%). The proportion of pregnancies in those with known HIV at conception increased over the time period. At conception 58 (60%) were on ART, 33 (57%) of who continued on their original regimen. 34 (35%) initiated ART following conception: 14 known to be HIV positive, 20 diagnosed during pregnancy. Two did not start ART (1 due to miscarriage, 1 as diagnosed post-delivery) and in three cases ART history was unavailable due to transfer to alternative centres. ART was initiated on average at 22 weeks gestation (range 6-34). 4(5%) received Zidovudine (AZT) monotherapy, all before 2006. Choice of combination ART (cART) varied with time reflecting changing guidelines. Prior to 2008 an AZT containing regimen was used in 83% versus 8% after. Planned mode of delivery was documented in 73: 30(41%) planned a normal vaginal delivery (NVD), 43(59%) a caesarean section (CS). The viral load (VL) was <50copies/mL in 58(76%) at 36 weeks and 64(84%) at delivery. 90% with a detectable VL at 36 weeks delivered via CS. 100% received neonatal post-exposure prophylaxis (PEP): 68(88%) AZT monotherapy, 9(12%) cART. 84% initiated PEP within four hours. 90% completed 28days. 8(10%) babies experienced side effects. In the 10-year review period, one infant (1.3%) was diagnosed HIV positive. Both mother and infant received care in accordance with guidelines, including neonatal PEP within 4hours. CONCLUSION: Care of the HIV positive pregnant woman in Brighton has been successful with overall transmission consistent with that seen nationally. Despite effective preventative strategies MTCT remains a risk and women should be counselled accordingly.

Peripheral Nerve Blocks for Surgery About the Knee.

Peripheral nerve blocks are an often-utilized and efficacious method of analgesia for orthopaedic surgery about the knee. Benefits include decreased pain and narcotic use, increased participation in postoperative physical therapy, and decreased length of hospital stay. Adductor canal blocks have the advantage of preserving quadriceps function for early postoperative range of motion and walking. The risk of serious complications resulting from a peripheral nerve block is relatively low, ranging from 0% to 3%.

Gunshot injuries of the spine.

BACKGROUND CONTEXT: Spinal gunshot injuries (spinal GSIs) are a major cause of morbidity and mortality in both military and civilian populations. These injuries are likely to be encountered by spine care professionals in many treatment settings. A paucity of resources is available to summarize current knowledge of spinal GSI evaluation and management. PURPOSE: The aim was to summarize the ballistics, epidemiology, evaluation, treatment, and outcomes of spinal GSI among civilian and military populations. STUDY DESIGN: This was a review of the current literature reporting spinal GSI management. METHODS: MEDLINE (PubMed) was queried for recent studies and case reports of spinal GSI evaluation and management. RESULTS: Spinal GSI now comprise the third most common cause of spinal injury. Firearms that produce spinal GSI can be divided into categories of high- and low-energy depending on the initial velocity of the projectile. Neural and mechanical spinal damage varies with these types and results from several factors including direct impact, concussion waves, tissue cavitation, and thermal energy. Management of spinal GSI also depends on several factors including neurologic function and change over time, spinal stability, missile tract through the body, and concomitant injury. Surgical treatment is typically indicated for progressive neurologic changes, spinal instability, persistent cerebrospinal fluid leak, and infection. Surgical treatment for GSI affecting T12 and caudal often has a better outcome than for those cranial to T12. Surgical exploration and removal of missile fragments in the spinal canal are typically indicated for incomplete or worsening neurologic injury. CONCLUSIONS: Treatment of spinal GSI requires a multidisciplinary approach with the goal of maintaining or restoring spinal stability and neurologic function and minimizing complications. Concomitant injuries and complications after spinal GSI can present immediate and ongoing challenges to the medical, surgical and rehabilitative care of the patient.

Degenerative meniscus: Pathogenesis, diagnosis, and treatment options.

The symptomatic degenerative meniscus continues to be a source of discomfort for a significant number of patients. With vascular penetration of less than one-third of the adult meniscus, healing potential in the setting of chronic degeneration remains low. Continued hoop and shear stresses upon the degenerative meniscus results in gross failure, often in the form of complex tears in the posterior horn and midbody. Patient history and physical examination are critical to determine the true source of pain, particularly with the significant incidence of simultaneous articular pathology. Joint line tenderness, a positive McMurray test, and mechanical catching or locking can be highly suggestive of a meniscal source of knee pain and dysfunction. Radiographs and magnetic resonance imaging are frequently utilized to examine for osteoarthritis and to verify the presence of meniscal tears, in addition to ruling out other sources of pain. Non-operative therapy focused on non-steroidal anti-inflammatory drugs and physical therapy may be able to provide pain relief as well as improve mechanical function of the knee joint. For patients refractory to conservative therapy, arthroscopic partial meniscectomy can provide short-term gains regarding pain relief, especially when combined with an effective, regular physiotherapy program. Patients with clear mechanical symptoms and meniscal pathology may benefit from arthroscopic partial meniscectomy, but surgery is not a guaranteed success, especially with concomitant articular pathology. Ultimately, the long-term outcomes of either treatment arm provide similar results for most patients. Further study is needed regarding the short and long-term outcomes regarding conservative and surgical therapy, with a particular focus on the economic impact of treatment as well.

Fertility preservation for cancer patients: a review.

Infertility can arise as a consequence of treatment of oncological conditions. The parallel and continued improvement in both the management of oncology and fertility cases in recent times has brought to the fore-front the potential for fertility preservation in patients being treated for cancer. Oncologists must be aware of situations where their treatment will affect fertility in patients who are being treated for cancer and they must also be aware of the pathways available for procedures such as cryopreservation of gametes and/or embryos. Improved cancer care associated with increased cure rates and long term survival, coupled with advances in fertility treatment means that it is now imperative that fertility preservation is considered as part of the care offered to these patients. This can only be approached within a multidisciplinary setting. There are obvious challenges that still remain to be resolved, especially in the area of fertility preservation in prepubertal patients. These include ethical issues, such as valid consent and research in the area of tissue retrieval, cryopreservation, and transplantation.

Gender differences in predicting high-risk drinking among undergraduate students.

The purpose of this study was to examine gender differences in college students' high-risk drinking as measured by an estimated blood alcohol concentration (eBAC) based on gender, height, weight, self-reported number of drinks, and hours spent drinking. Using a developmental/contextual framework, high-risk drinking is conceptualized as a function of relevant individual characteristics, interpersonal factors, and contextual factors regularly mentioned in the college drinking literature. Individual characteristics include race, gender, and age; interpersonal characteristics include number of sexual partners and having experienced forced sexual contact. Finally, contextual factors include Greek membership, living off-campus, and perception of peer drinking behavior. This study is a secondary data analysis of 1,422 students at a large university in the Southeast. Data were gathered from a probability sample of students through a mail survey. A three-step hierarchical logistic regression analysis showed gender differences in the pathway for high-risk drinking. For men, high-risk drinking was predicted by a combination of individual characteristics and contextual factors. For women, interpersonal factors, along with individual characteristics and contextual factors, predicted high-risk drinking, highlighting the importance of understanding female sexual relationships and raising questions about women's risk-taking behavior. Implications for prevention and assessment are discussed.

Percutaneous endoscopic gastrostomy with a jejunal port for severe hyperemesis gravidarum.

Hyperemesis gravidarum affects up to 2% of pregnancies and is characterized by severe nausea and vomiting persisting beyond the 14th week of gestation with weight loss, dehydration, electrolyte imbalance and ketonuria. We present the case of a woman with severe, refractory hyperemesis gravidarum in whom treatment with a percutaneous endoscopic gastrostomy with a jejunal extension allowed improvement of symptoms, reversal of maternal weight loss and the delivery of a healthy infant. Review of the literature reveals only one other paper describing this treatment. In all three cases successful outcomes for both mothers and children are described. We propose that percutaneous endoscopic gastrostomy with a jejunal extension is a safe, effective and relatively cheap intervention for severe, refractory hyperemesis gravidarum.

A study of the relationship between protective behaviors and drinking consequences among undergraduate college students.

The authors identified the number, type, and frequency of protective behaviors that undergraduate college students who consume alcohol use to prevent alcohol-related consequences. Their hypothesis was that students who engage in more types of protective behaviors with greater frequency would be less likely to experience alcohol-related consequences. Participants consisted of a randomly selected sample of 1,355 undergraduates aged 18 years and older at a large public university. Students completed a mailed questionnaire on alcohol and health behaviors in spring 2002. The findings (after adjustment for covariates) indicated that self-protective behaviors are inversely associated with alcohol-related problems for women but not for men. The influences of gender and racial and ethnic differences are considered in relation to prevention and intervention programs aimed at reducing alcohol-related consequences on college campuses.

Differences in African American and White college students' drinking behaviors: consequences, harm reduction strategies, and health information sources.

The authors explored the differences between African American and White college students' drinking behaviors and their attitudes toward consequences, harm-reduction strategies, and health information sources. They collected data from a randomly selected sample of 1,110 students in a large public university to examine the effects of a high-risk drinking prevention intervention. In the current analysis, they compared African American and White students on indicators of high-risk drinking, drinking consequences, harm-reduction strategies, the sources that students typically used for health information, and the believability of those sources. The African American students scored lower on drinking measures than the White students did, reported fewer negative consequences, and more regularly employed drinking-reduction strategies, with one exception--choosing a designated driver. Both African and White respondents reported that their parents were their most frequent and usual sources of health-related information and said that parents and health professionals were the most credible sources.