EW Groups Research Articles

Impact of early weaning and nutritional interventions on growth performance, digestive metabolism, and serum biomarkers in lambs: A biomechanical perspective

The aim of this study was to investigate the effects of early weaning and nutritional interventions on growth performance, nutrient digestion and metabolism, and serological indices of hu sheep lambs, with a view to providing a basis for the feasibility of early weaning of hu sheep lambs under conditions of supplemental milk replacer. Ninety neonatal hu sheep lambs were weaned at 21 days (n = 60) (divided into two groups: early weaned, EW; and resveratrol-fed, RSV) as well as 49 days (n = 30) (control group, CON) weaning, and the trial period was 90 days. The results showed that: 1) there was no significant difference (P > 0.05) in the initial and final weights of the lambs, and the average daily gain (ADG) of the EW and RSV groups was significantly lower than that of the CON group (P < 0.05) from 31 to 45 days of age. Early weaned lambs were more susceptible to weaning stress compared to late weaned lambs and the effect of nutritional intervention (feeding resveratrol) on lamb growth performance was not significant. 2) The apparent digestibility of crude protein (CP) in the experimental group was significantly lower than that of the control group (P < 0.05), and the nitrogen intake, net protein utilization and protein biological value indexes of lake lambs in the experimental group were significantly different from those of the control group (P < 0.05). 3) Early feeding of resveratrol was not significant in improving the digestive metabolism of nutrients. 4) Early weaning as well as the addition of resveratrol had a significant effect on the serum GLU and TC indexes of the lambs (P < 0.05), but did not show a significant effect on any of the other indexes.

Effects of chronic exposure to sublethal doses of neonicotinoids in the social wasp Polybia paulista: Survival, mobility, and histopathology

Several studies have investigated the consequences of exposure to neonicotinoids in honeybees. Given the lack of studies concerning the consequences of exposure of social wasps to neonicotinoids, as well as the ecological importance of these insects, the objective of this study was to test the hypothesis that chronic exposure to sublethal concentrations of thiamethoxam decreases survival and mobility by causing damage to the brain and midgut of the social wasp Polybia paulista. The wasps were exposed to different concentrations of thiamethoxam, in order to obtain the mean lethal concentration (LC50), which was used as a reference for calculation of two sublethal concentrations (LC50/100 and LC50/10) employed in subsequent experiments. To calculate survival, groups of exposed (EW) and unexposed (UW) wasps were monitored until death, allowing calculation of the average lethal time. The EW and UW groups were evaluated after 12, 24, 48, and 72 h of exposure, considering their mobility and histopathological parameters of the midgut and brain. A lesion index based on semiquantitative analyses was used for comparison of histopathological damage. The results demonstrated that exposure to the LC50/10 led to a significantly shorter survival time of the P. paulista workers, compared to unexposed wasps. In addition, both sublethal concentrations decreased mobility and caused damage to the intestine (loss of brush border, presence of spherocrystals, loss of cytoplasmic material, and pyknosis) and the brain (loss of cell contact and pyknosis), regardless of the exposure time. The findings showed that, like bees, social wasps are nontarget insects susceptible to the detrimental consequences of neonicotinoid use, with exposure leading to impaired survival, locomotion, and physiology.

Effects of early weaning on productive and reproductive performance of Nelore heifers

Abstract We aimed to evaluate the effects of early weaning on the productive and reproductive characteristics of Nelore heifer progeny. Ninety-five calves from primiparous (PRI) and multiparous (MUL) dams were assigned to one of two weaning strategies; 1) early weaning at 150 d (149 ± 1.97) of age (EW; n = 16 from PRI and 31 from MUL); or 2) conventional weaning at 240 d (247 ± 2.41) of age (CW; 16 from PRI and 32 from MUL). All heifers received ~5 g/kg of body weight (BW) of creep-feed as fed from 90 d of age until weaning. After weaning, each group of heifers was transferred to a Brachiaria spp. paddock and received 5 g/kg of BW of a protein-energy supplement until 12 mo of age. Then, heifers were confined and fed a diet with a ratio of 79:31 (corn silage: concentrate) for 4 mo, during which they were submitted to a hormonal protocol to induce puberty and timed artificial insemination (TAI). Reproductive tract score (RTS, 1 to 5 scale: 1 being infantile and 5 being cyclic) and endometrial thickness were determined at 12 mo of age, rump fat thickness (RFT), and BW every 28 ± 4 d through the breeding season, and plasma concentrations of IGF-I were evaluated at 12, 14, and 16 mo. At 15.6 mo of age heifers were submitted to a P4/E2 protocol for TAI at day 0 (D0), and a second TAI was performed at D22 in nonpregnant heifers. Ultrasound was used to determine the presence of corpus luteum on D10 and dominant follicle (DF) diameter and blood perfusion on D2 and D0. Data were analyzed using SAS by ANOVA or logistic regression. Though heifers from EW were lighter (P < 0.05) than CW at postweaning time points and CW presented a greater (P = 0.002) RFT than EW heifers from 11 to 15 mo, weaning strategy did not affect (P > 0.1) body condition score at TAI. Concentrations of IGF-I did not differ (P > 0.1) between heifers weaned at 150 and 240 d. The proportion of pubertal heifers, endometrium tone and thickness, and RTS at 16 mo did not differ (P > 0.1) between EW and CW groups. The diameter of DF on D2 and D0 and follicular blood perfusion on D0 were greater (P < 0.05) for heifers in the CW group than EW group, but P/AI at first and second TAI did not differ (P > 0.1) between groups. In conclusion, early weaning in Nelore heifers moderately reduces postweaning growth but does not affect puberty and reproductive performance before the breeding season when submitted to confinement.

Absence of a weekday effect on short- and long-term oncologic outcomes of gastrectomy for gastric cancer: a propensity score matching analysis

BackgroundDay of the week when elective gastrointestinal surgery is performed may be influenced by various background and tumor-related factors. Relationships between postoperative outcome and when in the week gastrectomy is performed remain controversial. We undertook this study to evaluate whether weekday of gastrectomy influenced outcomes of gastric cancer treatment (“weekday effect”).MethodsPatients who underwent curative surgery for gastric cancer between 2004 and 2017 were included in this retrospective study. To obtain 2 cohorts well balanced for variables that might influence clinical outcomes, patients whose gastrectomy was performed early in the week (EW group) were matched 1:1 with others undergoing gastrectomy later in the week (LW group) by use of propensity scores.ResultsAmong 554 patients, 216 were selected from each group by propensity score matching. Incidence of postoperative complications classified as Clavien-Dindo grade II or higher was similar between EW and LW groups (20.4% vs. 24.1%; P = 0.418). Five-year overall and recurrence-free survival were 86.0% and 81.9% in the EW group, and 86.2% and 81.1% in the LW group (P = 0.981 and P = 0.835, respectively).ConclusionsShort- and long-term outcomes were comparable between gastric cancer patients who underwent gastrectomy early and late in the week.

Early feeding strategies in lambs affect rumen development and growth performance, with advantages persisting for two weeks after the transition to fattening diets.

This study aimed to explore the effects of early feeding strategies on the growth and rumen development of lambs from pre-weaning to the transition to fattening diets. Ninety-six newborn, male lambs with similar body weights were randomly assigned to three treatments: fed starter at 42 days old + weaned at 56 days old (Ctrl, n = 36), fed starter at 7 days old + weaned at 56 days old (ES, n = 36), and fed starter at 7 days old + weaned at 28 days old (ES + EW, n = 24). The fattening diets of all lambs were gradually replaced from 60 to 70 days of age. Six randomly selected lambs from each treatment were slaughtered at 14, 28, 42, 56, 70, and 84 days of age. The results showed that the richness and diversity of rumen microbiota of lambs in the Ctrl group were distinct from those of lambs in the other groups at 42 days of age. Moreover, transcriptome analysis revealed 407, 219, and 1,211 unique differentially expressed genes (DEGs) in the rumen tissue of ES vs. Ctrl, ES vs. ES + EW, and ES + EW vs. Ctrl groups, respectively, at 42 days of age. Different early feeding strategies resulted in differences in ruminal anatomy, morphology, and fermentation in lambs from 42 to 84 days of age (P < 0.05). Lambs in the ES + EW group had a higher average starter diet intake than those in the other groups (P < 0.05) from 28 to 56 days of age, which affected their growth performance. After 42 days of age, the body and carcass weights of lambs in the ES and ES + EW groups were higher than those in the Ctrl group (P < 0.05). These findings demonstrate that feeding lambs with a starter diet at 7 days of age and weaning them at 28 days of age can promote rumen development and improve growth performance, and this advantage persists for up to 2 weeks after transition to the fattening diet.

Prostatic alterations associated to early weaning and its relation with cocoa powder supplementation. Experimental study in adult wistar rats.

ABSTRACTEarly weaning can predispose the offspring to greater risk of developing chronic diseases in adulthood. It is believed that the consumption of functional foods is able to prevent these effects. The aim of this study is to evaluate the effects of maternal and postnatal cocoa powder supplementation on body mass, metabolism, and morphology of the prostate of early weaned Wistar rats. The animals were divided into four experimental groups according to lactation time (21 or 18 days, n=6, each) as follows: control group (C), cocoa control group (CCa), early weaning group (EW), and cocoa early weaning group (EWCa). The animals were euthanized at 90 days of age. Serum biochemical analysis and prostate histomorphometric evaluation were performed. The animals supplemented with cocoa powder were heavier than their respective controls (p <0.05), although with no difference in food intake among the groups. Likewise, these same groups showed a reduction in the serum glucose in relation to C and EW groups (p <0.0001). With respect to the prostate, there was no difference in smooth muscle and lumen area densities, while the EW group had a lower epithelial height and a higher percentage of mast cells than the C group (p <0.05). On the other hand, the EWCa group managed to reverse these parameters, leveling with the controls. Early weaning resulted in hyperglycemia and important morphological changes in the prostate. In contrast, dietary supplementation with cocoa powder attenuated these effects on the metabolism and prostatic histoarchitecture, proving to be a good nutritional treatment strategy.

Presurgical Predictive Factors of Excess Weight Loss After Laparoscopic Sleeve Gastrectomy.

Conditions associated with surgical technique and postoperative lifestyle changes, as well as the characteristics of patients, may affect weight loss following laparoscopic sleeve gastrectomy. In this study, the effects of age, gender, BMI, and excess weight at the time of surgery on weight loss during follow-up were examined. Demographic data (age, gender), preoperative BMI, and weight values of the patients were recorded. TWL% and EWL% values of patients were recorded during follow-up at 1st, 3rd, 6th, 9th, 12th, and 18th months. Patients were grouped according to age (AGE1 < 30, AGE2 30-50, AGE3 ≥ 50years), BMI at the time of surgery (BMI1 ≤ 50, BMI2 > 50kg/m2), and EW at the time of surgery (EW1 ≤ 60, EW2 > 60kg). EWL% values obtained in the follow-up visits were compared among the gender, age, BMI, and EW groups. A total of 456 patients (371 females, 85 males) were operated. Mean EWL% was lower in AGE3 group (p < 0.001). Patients in AGE1 group had the highest mean EWL%, while those in BMI2 and EW2 groups had lower mean EWL% values throughout the follow-up period (p < 0.001). Regression analysis showed that age and BMI were associated with EWL% at all follow-up visits (p < 0.05). Patients with less than 60kg of excess weight, those with BMI ≤ 50kg/m2 and younger patients may lose weight more effectively following LSG.

Post-weaning rumen fermentation of Simmental calves in response to weaning age and relationship with rumination time measured by the Hr-Tag rumination-monitoring system

The present experiment aimed to investigate (1) the effect of weaning age on rumen fermentation, dietary intake, growth, and rumination behavior at 20 d after weaning in Simmental calves, and (2) the relationship between rumination time measured by the Hr-Tag rumination-monitoring system (Hr-Tag; SCR Engineers Ltd, Netanya, Israel) and rumen fermentation variables. Ten Simmental calves were randomly assigned at birth to be weaned at 45 (early weaning, EW) or 60 d of age (normal weaning, NW). EW calves were offered 6 L of bulk whole milk/d from d 2 to 38 and 3 L/d from d 39 to 45, while NW were offered 6 L of bulk whole milk/d from d 2 to 53 and 3 L/d from d 54 to 60. Individual calf starter intake was recorded daily and average daily gain (ADG) was calculated taken into account the BW at 6 d after weaning and final BW at 20 d after weaning. On d 20 after weaning, samples of rumen fluid were obtained via an esophageal tube. These samples were used to determine pH and volatile fatty acids (VFAs) concentration. Throughout the entire experiment, the Hr-Tag system continuously recorded the rumination time (RT) by Hr-Tag loggers positioned on the left side of the neck. No treatment differences were detected for total VFAs concentration and molar proportion of acetate, propionate, and butyrate (P > 0.05). Overall in the period -25 to 20 d relative to weaning time, daily RT did not differ between NW and EW calves and it increased around weaning in both groups. Hr-Tags revealed no differences in daily RT pattern (2h-RT) during the 3 d before rumen collection, while during the day (24 h) 2h-RT significantly varied overall in both EW and NW groups. Daily RT measured by Hr-Tags positively correlated to pH (r = 0.98; P < 0.001), and negatively correlated to concentration of total VFAs (r = −0.90; P < 0.001), acetate (r = −0.85; P < 0.001), and propionate (r = −0.90; P < 0.001). On the contrary, a positive linear relationship was found between daily RT and the molar proportion of acetate:propionate ratio (R2 = 0.76; P = 0.002). Results herein provide evidence that early weaning (45 d) in Simmental calves fed whole milk in the pre-weaning period did not impair rumen fermentations 20 d after weaning and BW gain. Surprisingly, the use of Hr-Tags could prove interesting for the prediction of rumen fermentation characteristics and patterns in calves after weaning. The collected data could be used to obtain quick information on rumen functionality allowing the identification in a timely fashion of those calves at a greater risk (i.e. marked decrease of rumen pH) during this critical transition phase, from liquid to only solid feeds, when rumen of calves is not completely developed and efficient. The provision of these results from Hr-Tags in calves may give some input for further research involving a greater number of calves to better establish correlations with phenotypic variables. Moreover, this device could be adopted in studies focused on the effect of different pre- and post-weaning diets or weaning management.

Synthesis and photophysical properties of isocoumarin-based D-π-A systems

We prepared a small library of polarity-sensitive fluorescent dyes characterized by an isocoumarin core properly functionalized with a conjugated push-pull system. The key step of the synthesis is based on a regio-selective silver(I)/p-TSA co-catalyzed cyclization of 2-alkynylbenzoates recently optimized in our laboratory. The photophysical properties of isocoumarin-based D-π-A systems have been investigated and a rationale was proposed based on their dipole moments and Hammett constants of the ED and EW groups involved.

Characteristics of Seizure and Antiepileptic Drug Utilization in Outpatients With Autoimmune Encephalitis.

Autoimmune encephalitis (AE) is one kind of encephalitis that associates with specific neuronal antigens. Most patients with AE likely suffer from seizures, but data on the characteristics of seizure and antiepileptic drugs (AEDs) utilization in this patient group remains limited. This study aimed to report the clinical status of seizure and AEDs treatment of patients with AE, and to evaluate the relationship between AEDs discontinuation and seizure outcomes. Patients with acute neurological disorders and anti-N-methyl-D-aspartate receptor (NMDAR), γ-aminobutyric acid B receptor (GABABR), leucine-rich glioma inactivated 1, or contactin-associated protein-like 2 (CASPR2) antibodies were included. As patients withdrew from AEDs, they were divided into the early withdrawal (EW, AEDs used ≤3 months) and late withdrawal (LW, AEDs used >3 months) groups. Seizure remission was defined as having no seizures for at least 1 year after the last time when AEDs were administered. Seizure outcomes were assessed on the basis of remission rate. The factors affecting the outcomes were assessed through Spearman analysis. In total, we enrolled 75 patients (39 patients aged <16 years, male/female = 39/36) for follow-up, which included 67 patients with anti-NMDAR encephalitis, 4 patients with anti-GABABR encephalitis, 2 patients with anti-voltage-gated potassium channel encephalitis, and 2 patients with coexisting antibodies. Among the 34 enrolled patients with anti-NMDAR encephalitis who were withdrawn from AEDs, only 5.8% relapse was reported during the 1-year follow-up, with no significant difference in the percentage of relapse between the EW and LW groups (P = 0.313). Fifteen patients (an average age of 6.8, 14 patients with anti-NMDAR encephalitis and 1 patient with anti-CASPR2 encephalitis) presented seizure remission without any AEDs. Seventy five percent of patients with anti-GABABR antibodies developed refractory seizure. Other risk factors which contributed to refractory seizure and seizure relapse included status epilepticus (P = 0.004) and cortical abnormalities (P = 0.028). Given this retrospective data, patients with AE have a high rate of seizure remission, and the long-term use of AEDs may not be necessary to control the seizure. Moreover, seizures in young patients with anti-NMDAR encephalitis presents self-limited. Patients with anti-GABABR antibody, status epilepticus, and cortical abnormalities are more likely to develop refractory seizure or seizure relapse.

Body composition and dairy intake in sedentary employees who participated in a healthy program based on nutrition education and Zumba

The dairy intake is associated with body composition; however, its effect is controversial and remains unknown in relation to exercise interventions as Zumba Fitness®. Thus, we analyzed the body composition and its relation to dairy intake in sedentary employees who participated in a healthy program based on nutrition education and Zumba Fitness®. Sixty-nine sedentary employees (age=38.41±7.45-yr, 81.16% women) participated in a healthy program (16-weeks) based on nutrition education (2 sessions, 1st and 10th week) and Zumba Fitness® (ZF) exercise programs [2 interventions: a) ZF, 1h of ZF/3day/week; b) ZF+BW, 1h of ZF/3day/week plus 20min of bodyweight training]. Body composition (body weight, height, BMI, waist-hip index, ∑6-skinfolds, fat mass and muscle mass), blood pressure and dairy intake (milk, yogurt and cheese) were assessed at baseline and after interventions. Participants were categorized into normal weight (NW, BMI=18.5-24.9Kg/m2) and excess weight (EW, BMI≥25Kg/m2). Dairy intake and changes in BMI (ΔBMI=BMI after intervention-BMI at baseline) were divided into tertiles (T). Only muscle mass (Kg) differed between ZF and ZF+BW (baseline and 16-weeks). Anthropometric indicators of adiposity were lower in NW than EW group (baseline). The ∑6-skinfolds and fat-mass decreased, while muscle mass increased in ZF and ZF+BW, and in NW and EW groups (16-weeks). The most consumed dairy was milk (baseline). Participants of T1 of cheese intake (baseline) had a higher reduction in BMI (0.42±0.56 vs 0.62±1.42Kg/m2) and in ∑6-skinfolds (40.23±13.13 vs 23.51±10.84mm) than individuals in T3 (16-weeks). Employees who presented higher weight loss (T3, BMI decrease>0.50Kg/m2) consumed lower cheese than the weight gain group (T1, BMI increase≥0.33Kg/m2) (baseline). Healthy programs based on nutrition education and Zumba Fitness® improve body composition both in EW and NW sedentary employees. ZF is as effective as ZF+BW. A lower cheese intake, at baseline, but not milk or yogurt, was related to a weight loss.

Long-term effect of early nutrition on endocrine parameters and liver and endometrial gene expression of the members of the somatotrophic axis in Hereford heifers.

This study compared the effect of different management systems on endocrine parameters, and gene expression of members of the somatotrophic axis in the liver and endometrium of beef heifers. Twenty-two 709-days-old heifers submitted to Early Weaning (EW, n=8), Traditional Weaning (TW, n=7) and TW plus creep feeding (TW+CF, n=7) were used. Animals were synchronized with two prostaglandin (PG) injections at 11-day interval (Oestrus=Day 0). Blood samples were collected daily for progesterone (P4) determination, and endometrial and liver biopsies on Days 7 and 16 for transcript determination of members of the somatotrophic axis. Progesterone concentrations were greater on Days 15 and 16 (p<.02) of the cycle in TW+CF than TW and EW heifers. On Day 7, TW+CF heifers expressed greater liver total growth hormone receptor transcripts than TW heifers (p=.05) and greater insulin-like growth factor (IGF)-binding protein 3 mRNA than both EW and TW groups (p<.05). On Days 7 and 16, TW+CF expressed more endometrial IGF1 mRNA than the other groups (p<.01). We conclude that increasing the plane of nutrition of nursing calves may have a long-term effect on the functioning of the somatotrophic axis both in the liver and in the endometrium.

Structural and electronic modifications of pyridones and pyrones via regioselective bromination and trifluoromethylation

We report regioselective functionalization of pyridones and pyrones via electrophilic bromination (Br2) or radical trifluoromethylation (NaSO2CF3/tBuOOH) at the 3-position. Counter-intuitively, the 3-position EW groups decreased the carbonyl stretching energy by 6–23 cm−1; however, 3,5-dibromination increased the CO frequency by 10–22 cm−1 compared to the 3-Br pyridones. X-ray crystallography revealed pyridone tautomers with contracted CO bond metrics. pKa values and 1H NMR shifts for the series 3-H→Br→CF3 revealed the expected trend of increasing acidity (pKa = 8.85 → 8.33→6.78, MeOH) and increasing chemical shifts (10.97 → 11.42→11.71 DMSO-d6). We conclude that the paradoxical decrease in CO stretching frequencies by the 3-positoin EW groups is explained by an ‘assistive’ electron-withdrawing effect, whereby the 3-position EW group assists the electronegative oxygen atom in recruiting more electron density, and – as a result – attaining more oxyanion character (decreased the CO bond strength).

Randomized controlled trial of topical EMLA and breastfeeding for reducing pain during wDPT vaccination

The primary objective was to evaluate the analgesic effect of a eutectic mixture of local anesthetics (EMLA) during whole cell DPT vaccination. The secondary objective was to evaluate if the analgesic effect of EMLA was synergistic to breastfeeding. A randomized, placebo-controlled trial was done to include infants of up to 3 months of age who came for their first DPT vaccination. The outcome variables were duration of cry, latency of onset of cry, and Modified Facial Coding Score. Thirty babies were enrolled in each of three groups. The groups did not differ significantly in baseline characteristics. Median (interquartile range) of duration of cry was least [34.6 (24.1-72.2) s] in babies receiving EMLA cream with breastfeeding (EB group), followed by 94.2 (46.1-180) s in babies receiving EMLA cream with oral distilled water (EW group), as compared to 180.0 (180-180) s in babies receiving placebo cream with oral distilled water (PCW group) (p < 0.05). Mean (SD) of latency of cry was significantly greater in EB group [2.4 (1.14) s] and EW group [1.9 (0.62) s] as compared to babies in PCW group [1.5 (0.47) s] (p < 0.05), but the difference between EB and EW groups was not significant. Modified Facial Coding Score was significantly lower in EB group as compared to the other groups (p < 0.05). Topical EMLA is effective in reducing pain and has a synergistic effect in analgesia when combined with breastfeeding during vaccination in infants.

복숭아의 세척시스템 개발 및 특성 평가

This study was conducted to find condition of improving the quality of peach by using surfacing washing system. The rate of weight loss of A,B groups were showed slower decreasing trend than CT group and the value of soluble solid degree was not different significantly among all groups from the results of stored peach treat with surface washing system of peach in the first experiment. The colory value of surface were increased with increasing storage period in all treatments. Browning pace of A,B groups were slower than control. Emission of carbon dioxide was increased from the results of respiration rate, 6-10 mL/kg/hr <TEX>$(10^{\circ}C)$</TEX> and 32-41 mL/kg/hr <TEX>$(25^{\circ}C)$</TEX>. In second experiment with surface washing system of peach, the value of soluble solid was showed with similar value from 10 <TEX>$Brix^{\circ}$</TEX> to 13 <TEX>$Brix^{\circ}$</TEX>. The pace of soft rot of EW groups were lower than CT groups from the results of hardness during storage period. The results of colory value was not showed with significant difference in <TEX>$15^{\circ}C$</TEX> and <TEX>$20^{\circ}C$</TEX> storage temperature but changed to browning in EW groups. The moisture contents was from 85% to 90% in all groups. And the count of total microorganism of EW groups were lower than control. Also total coliform of EW groups were negative. In sensory evaluation, washing peach was showed higher value with significant difference in all acceptability.

On the Mechanism of Nitrosoarene−Alkyne Cycloaddition

The thermal reaction between nitrosoarenes and alkynes produces N-hydroxyindoles as the major products. The mechanism of these novel reactions has been probed using a combination of experimental and computational methods. The reaction of nitrosobenzene (NB) with an excess of phenyl acetylene (PA) is determined to be first order in each reactant in benzene at 75 degrees C. The reaction rates have been determined for reactions between phenyl acetylene with a set of p-substituted nitrosoarenes, 4-X-C(6)H(4)NO, and of 4-O(2)N-C(6)H(4)NO with a set of p-substituted arylalkynes, 4-Y-C(6)H(4)C[triple bond]CH. The former reactions are accelerated by electron-withdrawing X groups (rho = +0.4), while the latter are faster with electron-donating Y groups (rho = -0.9). The kinetic isotope effect for the reaction of C(6)H(5)NO/C(6)D(5)NO with PhC[triple bond]CH is found to be 1.1 (+/-0.1) while that between PhC[triple bond]CH/PhC[triple bond]CD with PhNO is also 1.1 (+/-0.1). The reaction between nitrosobenzene and the radical clock probe cyclopropylacetylene affords 3-cyclopropyl indole in low yield. In addition to 3-carbomethoxy-N-hydroxyindole, the reaction between PA and o-carbomethoxy-nitrosobenzene also affords a tricyclic indole derivative, 3, likely derived from trapping of an intermediate indoline nitrone with PA and subsequent rearrangement. Computational studies of the reaction mechanism were carried out with density functional theory at the (U)B3LYP/6-31+G(d) level. The lowest energy pathway of the reaction of PhNO with alkynes was found to be stepwise; the N-C bond between nitrosoarene and acetylene is formed first, the resulting vinyl diradical undergoes cis-trans isomerization, and then the C-C bond forms. Conjugating substituents Z on the alkyne, Z-C[triple bond]CH, lower the calculated (and observed) activation barrier, Z = -H (19 kcal/mol), -Ph (15.8 kcal/mol), and -C(O)H (13 kcal/mol). The regioselectivity of the reaction, with formation of the 3-substituted indole, was reproduced by the calculations of PhNO + PhC[triple bond]CH; the rate-limiting step for formation of the 2-substituted indole is higher in energy by 11.6 kcal/mol. The effects of -NO(2), -CN, -Cl, -Br, -Me, and -OMe substituents were computed for the reactions of p-X-C(6)H(4)NO with PhC[triple bond]CH and of PhNO and/or p-NO(2)-C(6)H(4)NO with p-Y-C(6)H(4)C[triple bond]CH. The activation energies for the set of p-X-C(6)H(4)NO vary by 4.3 kcal/mol and follow the trend found experimentally, with electron-withdrawing X groups accelerating the reactions. The range of barriers for the p-Y-C(6)H(4)C[triple bond]CH reactions is smaller, about 1.5 and 1.8 kcal/mol in the cases of PhNO and p-NO(2)-PhNO, respectively. In agreement with the experiments, electron-donating Y groups on the alkyne accelerate the reactions with p-NO(2)-C(6)H(4)NO, while both ED and EW groups are predicted to facilitate the reaction. The calculated kinetic isotope effect for the reaction of C(6)H(5)NO/C(6)D(5)NO with PhC[triple bond]CH is negligible (as found experimentally) while that for PhC[triple bond]CH/PhC[triple bond]CD with PhNO (0.7) differs somewhat from the experiment (1.1). Taken together the experimental and computational results point to the operation of a stepwise diradical cycloaddition, with rate-limiting N-C bond formation and rapid C-C connection to form a bicyclic cyclohexadienyl-N-oxyl diradical, followed by fast tautomerization to the N-hydroxyindole product.

Theoretical Insights, in the Liquid Phase, Into the Antioxidant Mechanism-Related Parameters in the 2-Monosubstituted Phenols

The paper describes a DFT/B3LYP study, in the liquid phase, [using the PCM continuum model] on the O-H bond dissociation enthalpy (BDE) and ionization energy (IE) parameter values of the 2-monosubstituted phenols (2-X-ArOH), related to the H-atom transfer (HAT) and single-electron transfer (SET) mechanisms. The solvent and substituent effects on the conformers, the BDEs, and the IEs were studied using four electron-donating (EDG) and five electron-withdrawing (EWG) groups, in seven different solvents. In both the EDG- and/or EWG-substituted species of the parent compounds, radicals, and/or cation radicals, the most stable conformer is varied, depending on the medium and the substitution. The EWG-substituents increase IEs, resulting in a weaker antioxidant activity than the EDG ones; the effect appears stronger on the IEs than on BDEs. However, although the liquid-phase IEs, which are related to solution-phase oxidation potentials, decrease with the polarity and/or the hydrogen-bonding ability of the solvent, the opposite holds true for the BDEs, exhibiting a weaker effect. The gas-phase-calculated IE for benzene is among the most accurate ones in the field, compared to the experiment, that for phenol being the most accurate. In addition, calculated IEs for the 2-X-ArOH are in close agreement with the very few existing experimental ones. It is shown that the oxidation potentials are (a) highly correlated with the gas-phase ones, and (b) strongly solvent dependent. The stabilization/destabilization of the cation radical (SPC) contribution, in all media, is the decisive factor in the DeltaIE calculation. The reasonable correlations found between the DeltaBDE and DeltaIE could account well for the assumption of the simultaneous action of both mechanisms in the 2-X-ArOH, in both the gas and the liquid phase. It seems, however, that the presence of a particular solvent by itself is not sufficient enough for the HAT to SET transition. The involvement of specific ED and/or EW groups in the 2-X-ArOH seems also necessary. It appears that our theoretical approach is not only generally applicable to the set of substituents important to antioxidant activity but also useful in (a) the rational design of phenolic antioxidants and (b) affording accurate BDE and IE parameter values related to both possible antioxidant mechanisms.

Alendronate Therapy May Be Effective in the Prevention of Bone Loss Around Titanium Implants Inserted in Estrogen‐Deficient Rats

This study evaluated whether alendronate (ALD) influences bone healing around titanium implants inserted in ovariectomized rats and whether it provides a residual effect after its withdrawal. Bilateral ovariectomies were performed in 87 Wistar rats and one screw-shaped titanium implant was placed in the tibiae. The animals were divided into the following groups: group SHAM (N = 15): sham surgeries; group OVX (N = 15): ovariectomy; group AT (N = 15): OVX plus alendronate administration for 80 days; group AW (N = 14): OVX plus alendronate administration for 40 days; group ET (N = 14): OVX plus 17beta estradiol administration for 80 days; or group EW (N = 14): OVX plus 17beta estradiol administration for 40 days. Bone-to-implant contact (BIC), bone area (BA) within the limits of implant threads, and bone density in a 500 microm-wide zone lateral to the implant (BD) were obtained and measured for the cortical (zone A) and cancellous (zone B) regions. In zone A, data analysis showed no significant differences among the groups regarding BIC and BD (P >0.05), and a slight beneficial effect of estradiol on BA when compared with the OVX, EW, and AW groups (P <0.05). In zone B, OVX negatively impacted bone healing around the implants, resulting in reduced BA and BD (P<0.05). ALD (continuous/interrupted) and estradiol (only continuous) positively affected BIC, BA, and BD, resulting in values at the same level as the control group (SHAM). ALD may prevent the negative influence of estrogen deficiency on bone healing around titanium implants inserted in OVX rats. This positive effect, in contrast to estradiol, is sustained following its withdrawal.

Indução hormonal da ovulação e desmame precoce na fertilidade pós-parto de vacas de corte homozigotas e heterozigotas para o microssatélite BMS3004

O objetivo deste experimento foi comparar a eficiência de um programa hormonal associado ao desmame temporário por 96 horas na indução do estro e ovulação com o desmame definitivo aos 60 dias em vacas de corte. Foram utilizadas 183 vacas de corte amamentando, das raças Charolês (C), Nelore (N) e suas cruzas recíprocas, as quais foram genotipadas como homozigotas (HOM) ou heterozigotas (HET) para o microssatélite (STR) BMS3004, que está localizado no mesmo cromossomo do gene da cadeia beta do LH. Entre 60 e 80 dias pós-parto (dia 0), as vacas foram distribuídas em dois grupos. No grupo indução hormonal (IH), as vacas (n=87) receberam (dia 0) 250 mg de acetato de medroxiprogesterona por 8 dias, 2,5 mg de benzoato de estradiol (dia 1) e 500 UI de gonadotrofina coriônica eqüina (dia 7). No dia 8, os bezerros foram desmamados por 96 horas. No mesmo dia (dia 8), as vacas (n=96) do outro grupo apenas foram submetidas ao desmame definitivo (grupo DP). Após, procedeu-se 4 dias de inseminação artificial (IA) e, passado esse período, foram entouradas. O primeiro diagnóstico de gestação (DG) foi realizado 60 dias após o período de IA e, o segundo, 60 dias após o final do entoure. As taxas de estro foram maiores nas vacas do grupo IH em relação as do grupo DP. As vacas com condição corporal 2,5 e 3,0 apresentaram menores percentuais de prenhez ao 1ºDG no grupo IH (29,6 e 46,4%) em relação ao grupo DP (56,0 e 72,2%). Os percentuais de prenhez das vacas com índice corporal 65-73 não diferiram entre os grupos IH e DP. As vacas N do grupo IH, apresentaram menor percentual de prenhez ao 1ºDG que as F1 (27,7 vs. 64,2%), mas não diferiram em relação às C (40,0%). No grupo IH, o percentual de prenhez ao 2ºDG foi menor nas vacas HOM do que nas HET. O desmame definitivo precoce mostrou-se mais eficaz no incremento dos percentuais de prenhez em vacas de corte.

Age of calf at weaning of spring-calving beef cows and the effect on cow and calf performance and production economics.

Over a 5-yr period, spring-calving cows were used in a carry-over design experiment to evaluate effects of calf age at weaning on cow and calf performance and production economics. Weaning management groups were early (n = 60, calf age 150 d, EW), traditional (n = 60, calf age 210 d, NW), and late (n = 60, calf age 270 d, LW). Cow body condition score (BCS) and weights at the last weaning date were different (P < .05) for EW (5.8, 583 kg), NW (5.5, 560 kg), and LW (5.2, 541 kg) management groups. Pregnancy rates among groups were similar. Days on feed for groups differed (P = .001) and was 247 for EW, 204 for NW, and 164 d for LW steers. Average daily gain in the feedlot differed (P = .01) among groups and averaged 1.5 kg for LW, 1.4 kg for NW, and 1.3 kg for EW steers. Dry matter intake while steers were in the feedlot was greater (P = .001) for LW than for NW and EW calves. Hot carcass weight was greater (P = .01) for EW (328 kg) and NW (332 kg) calves than for LW (321 kg) steers, and fat depth was greater (P = .05) for EW and NW steers than for LW steers. When carcass data for the NW and LW steers were adjusted to the fat depth of EW steers, carcass characteristics among groups were similar. Net income per steer at slaughter for the feedlot phase was greater (P < .001) for the EW ($75.36) and NW ($62.16) steers than for the LW ($10.09) steers. Again, when carcass data for the NW and LW steers were adjusted to the same fat depth of the EW steers, net income differences among groups were reduced. Replacement heifers were developed in a drylot and costs were higher (P < .001) for the EW than for NW and LW heifers. Annual cow costs were greater (P < .10) for the LW ($443.45) than for the EW ($410.09) and NW ($421.35) groups. Break-even for each system on a steer financial basis was not different between the NW and LW groups, and both the NW and LW groups had lower (P = .08) break-evens than the EW group. Age of the calf at weaning affects cow weight and BCS. Net income in each system is influenced by cow costs, month of the year that steer calves are purchased into the feedlot and finished steers are sold, month of the year cull cows are marketed, and replacement heifer development costs.