This paper reports the predominantly syndiotactic‐specific polymerization of propylene in the presence of titanium monoamidinate/methylaluminoxane (MAO) catalysts. The same catalysts, depending on the reaction conditions, also promote either predominantly 1,4‐cis or 1,4‐trans polymerization of 1,3‐butadiene and polymerization of styrene either to highly syndiotactic or to stereoirregular polymer. Some preliminary information about the features of propylene polyinsertion is also reported.
Expansion of the 20–24 ppm region of the 13C NMR spectrum of sample 2. The starred resonance at 21.75 ppm and the shoulders are not assigned. 相似文献
Bacteria of the genus Wolbachia constitute a group of intracellular and maternally inherited micro-organisms that are widespread in arthropods, inducing several reproductive disorders such as cytoplasmic incompatibility in their hosts. Considering relevant biological implications related to the presence of Wolbachia in several insect orders, for example its potential role as mechanism for rapid speciation and as vehicle to drive genetic markers in wild populations of vectors of medical and veterinary interest, we carried out an extensive polymerase chain reaction survey to detect Wolbachia in several species of mosquito belonging to genera involved in the transmission of pathogens. Five species out of 26 tested have shown to be infected; for four of them this is the first evidence of the Wolbachia infection. A phylogenetic analysis was also performed, positioning the five Wolbachia strains in the phyletic subdivision B. 相似文献
8 cultivars of the commercial tomato ( LYCOPERSICON ESCULENTUM) and 4 species of wild tomato plants ( L. HIRSUTUM, L. PIMPINELLIFOLIUM, L. GLANDULOSUM, L, PERUVIANUM) were investigated with regard to their production of 2-tridecanone in leaflets, petioles and stems during different stages of development and under different conditions of cultivation. The significance of 2-tridecanone as defence substance against fungal pathogens and pests of LYCOPERSICON spp. is discussed. 相似文献
Prevention Science - The NAMWEZA intervention was implemented, using a ten-session group format, to build skills targeting psychosocial vulnerabilities and enhancing HIV prevention among people... 相似文献
ObjectiveTo determine differences by Child and Adult Care Food Program (CACFP) participation on nutrition requirements and best practices and barriers to implementing both in early care and education programs (ECEs) stratified by context (centers vs home-based ECEs).DesignCross-sectional survey.SettingThree-thousand and fourteen licensed Nebraska ECEs in 2017.ParticipantsOne-thousand three hundred forty-five ECEs.Main Outcome Measure(s)Director-reported nutrition practices in classrooms serving children aged 2-5 years (8 requirements for foods served, 5 best practices for foods served, and 14 best practices for mealtime behaviors).AnalysisChi-square analysis adjusted for multiple comparisons.ResultsOf the sample, 86.8% participated in CACFP, 21.7% were center-based, and 78.3% were home-based. Overall, CACFP participation was related to the higher implementation of CACFP requirements for foods served (P < 0.004 for all) and receiving professional development on nutrition (P < 0.012). In home-based ECEs only, CACFP participation was related to a higher prevalence of serving meals family-style (P = 0.002); however, these practices had low implementation overall.Conclusion and ImplicationsFindings suggest strengthening of requirements to include staff mealtime behaviors beyond service of healthful foods. Improving CACFP enrollment and including CACFP standards in state licensing requirements may be key strategies for improving nutrition practices in ECEs. 相似文献
A Coronavirus Disease 2019 (COVID-19)–specific Hospital-at-Home was implemented in a 400-bed tertiary hospital in Barcelona, Spain. Senior or immune-compromised physicians oversaw patient care. The alternative to inpatient care more than doubled beds available for hospitalization and decreased the risk of transmission among patients and health care professionals. Mild cases from either the emergency department or after hospital discharge were deemed suitable for admission to the Hospital-at-Home. More than half of all patients had pneumonia. Standardized protocols and management criteria were provided. Only 6% of cases required referral for inpatient hospitalization. These results are promising and may provide valuable insight for centers undertaking Hospital-at-Home initiatives or in the case of new COVID-19 outbreaks. 相似文献
Knowledge of preoperative right heart function of adult patients with cystic fibrosis (CF) awaiting lung transplant (LUTX) is limited. The echocardiography of adult patients with CF enlisted for LUTX was retrospectively analyzed and compared with standards and invasive analyses (right heart catheterization, multigated radionuclide ventriculography). We included 49 patients (reported as mean ± standard deviation; 29 ± 9 years of age; forced expiratory volume in first second of expiration, 31% ± 11% predicted; lung allocation score, 36 ± 5; invasive mean pulmonary artery pressure, 17 ± 5 mm Hg; multigated radionuclide ventriculography right ventricle [RV] ejection fraction, 50% ± 9%). Patients had increased RV end-diastolic area, RV wall thickness, and increased pulmonary artery acceleration time with subnormal tricuspid annular plane systolic excursion, tissue Doppler positive peak systolic velocity, and fraction area change. Subnormal tricuspid annular plane systolic excursion (< 23 mm), tissue Doppler positive peak systolic velocity (< 14 cm/s), and fraction area change (< 49%) had high sensitivity and negative predictive value in predicting impaired RV.ejection fractionA good correlation between echocardiographic estimated and invasively measured systolic pulmonary artery pressure was observed (R2 = 0.554, P < .001). Adults with CF awaiting LUTX have morphologic alterations of the right heart, with subclinical impairment of RV systolic function. Echocardiography may be used as a bedside, repeatable, and reliable noninvasive test to screen further deterioration in RV function while on the waiting list for LUTX. More prospective follow-up echocardiographic studies are necessary to confirm such a hypothesis. 相似文献
Radiation-induced breast angiosarcoma, or secondary angiosarcoma (SAS), is a rare entity with a high risk of metastatic recurrence. Herein, we describe the use of intraoperative fluorescence-based skin angiography to guide surgical resection following a novel immunotherapy-based regimen for SAS resulting in a complete pathological response. 相似文献
Quality of Life Research - Caregivers, or proxies, often complete patient-reported outcome measures (PROMs) on behalf of patients with stroke. The objective of our study was to assess the validity... 相似文献