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51.
Fipronil is an insecticide widely used to control a great number of pests, thus the aim of this study was to determine the lethal dose and lethal concentration (LD50 and LC50) of this insecticide to the stingless bees Scaptotrigona postica Latreille, 1807. The LD50 and LC50 values obtained after 24 h of exposition were of 0.54 ng a.i./bee and 0.24 ng a.i./μL diet, respectively. These values were considered highly toxic to stingless bees.  相似文献   
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Clinical Oral Investigations - To investigate the physical–chemical properties of home bleaching gels based on Carbamide Peroxide (CP) and Hydrogen Peroxide (HP) after accelerated stability...  相似文献   
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Exclusive breastfeeding (EBF) for the first 6 months of life improves survival, growth and development. In Kenya, recent legislation and policies advocate for maternity leave and workplace support for breastfeeding and breast milk expression. We conducted a qualitative study to describe factors influencing EBF for 6 months among mothers employed in commercial agriculture and tourism. We interviewed employed mothers (n = 42), alternate caregivers and employed mothers'' husbands (n = 20), healthcare providers (n = 21), daycare directors (n = 22) and commercial flower farm and hotel managers (n = 16) in Naivasha, Kenya. Despite recognizing the recommended duration for EBF, employed mothers describe the early cessation of EBF in preparation for their return to work. Managers reported supporting mothers through flexible work hours and duties. Yet, few workplaces have lactation spaces, and most considered adjusting schedules more feasible than breastfeeding during work. Managers and healthcare providers believed milk expression could prolong EBF but thought mothers lack experience with pumping. The most frequently suggested interventions for improving EBF duration were to expand schedule flexibility (100% of groups), provide on‐site daycare (80% of groups) and workplace lactation rooms (60% of groups), improve milk expression education and increase maternity leave length (60% of groups). Returning to work corresponds with numerous challenges including lack of proximate or on‐site childcare and low support for and experience with milk expression. These factors currently make EBF for 6 months unattainable for most mothers in these industries. Interventions and supports to improve breastfeeding upon return to work are recommended to strengthen employed mothers'' opportunity for EBF.  相似文献   
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Objective  Acrylamide, a probable human carcinogen, is formed during high-heat cooking of many common foods. The validity of food frequency questionnaire (FFQ) measures of acrylamide intake has not been established. We assessed the validity of acrylamide intake calculated from an FFQ using a biomarker of acrylamide exposure. Methods  We calculated acrylamide intake from an FFQ in the Nurses’ Health Study II. We measured hemoglobin adducts of acrylamide and its metabolite, glycidamide, in a random sample of 342 women. Correlation and regression analyses were used to assess the relationship between acrylamide intakes and adducts. Results  The correlation between acrylamide intake and the sum of acrylamide and glycidamide adducts was 0.31 (95% CI: 0.20–0.41), adjusted for laboratory batch, energy intake, and age. Further adjustment for BMI, alcohol intake, and correction for random within-person measurement error in adducts gave a correlation of 0.34 (CI: 0.23–0.45). The intraclass correlation coefficient for the sum of adducts was 0.77 in blood samples collected 1–3 years apart in a subset of 45 women. Intake of several foods significantly predicted adducts in multiple regression. Conclusions  Acrylamide intake and hemoglobin adducts of acrylamide and glycidamide were moderately correlated. Within-person consistency in adducts was high over time.  相似文献   
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To assess if sensory-motor-oral stimulation and non-nutritive sucking gavage feeding enhances the oral feeding performance of preterm infants born between 26 and 32 weeks of gestational age. STUDY DESIGN: Very low birthweight infants (n=98) were randomized into a experimental and control group. Preterm infants in the experimental group received sensory-motor-oral stimulation and non-nutritive sucking and infants in the control group received a sham stimulation program. Both were administered from when they reached enteral diet (100 kcal/kg/day) until the beginning of oral diet. Primary outcome was length of hospital stay. RESULTS: Independent oral feeding was attained significantly earlier in the experimental group than the control group, 38+/-16 days of life (mean+/-S.D.) versus 47+/-17 days of life, respectively (P<0.001) There was significant difference in length of hospital stay between the two groups (41.9+/-17 (mean+/-S.D.) versus 52.3+/-19 days (P<0.01)). CONCLUSION: Sensory-motor-oral stimulation, together with early non-nutritive sucking (as soon as the newborn reaches full diet and is clinically stable) in very low birthweight preterm infants, as long as they are clinically stable, in this study, earlier initiation of oral feeding and earlier hospital discharge.  相似文献   
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Household food insecurity (HFI) is a powerful stressor negatively associated with early childhood development (ECD). However, no comprehensive review has examined the association of HFI and ECD. Therefore, this systematic review and meta‐analysis investigated the association between HFI and ECD domains and subdomains in children under 5 years old. Peer‐reviewed and grey literature were systematically searched in electronic databases with no year or language restrictions. Studies were eligible if they assessed the association between HFI and one or more ECD domains. Data were extracted using a standard predefined protocol. Meta‐analysis was performed, and the heterogeneity across studies was explored. Nineteen studies were included in the systematic review and 14 in the meta‐analysis. Of the studies, 15 were from high income countries (HICs) and four from low–middle income countries (LMICs). For developmental risk and the cognitive/math and cognitive/school readiness and reading subdomains, the only studies available were conducted in HICs. The meta‐analysis showed that HFI was associated with developmental risk (OR 1.28; 95% CI [1.14, 1.45]), cognitive/vocabulary (OR 0.94; 95% CI [0.90, 0.98]), and cognitive/math (OR 0.84; 95% CI [0.73, 0.96]). HFI was marginally associated with cognitive/school readiness and reading (OR 0.91; 95% CI [0.82, 1.00]) and motor development (OR; 0.91, 95% CI [0.80, 1.04]). HFI was associated with poor ECD in children under 5 years old. Specifically, HFI was associated with developmental risk and poor math skills in studies conducted in HICs and with poor vocabulary skills in studies conducted in both HICs and LMICs. Prospective studies examining HFI and ECD are needed in LMICs.  相似文献   
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