Impacts of estrus expression and intensity during a timed-AI protocol on variables associated with fertility and pregnancy success in Bos indicus-influenced beef cows.

This experiment evaluated the impacts of estrus expression and intensity, estimated by physical activity during a timed-AI protocol, on reproductive performance of Bos indicus-influenced beef cows. A total of 290 lactating, primiparous, and multiparous nonpregnant Nelore × Angus cows received a 2 mg injection of estradiol benzoate and an intravaginal progesterone (P4) releasing device (CIDR) on d -11, a 12.5 mg injection of PGF2α on d -4, CIDR removal in addition to 0.6 mg injection of estradiol cypionate and 300 IU injection of eCG on d -2, and timed-AI on d 0. Cows were fitted with a pedometer behind their left shoulder on d -4. An estrus detection patch was attached to the tail-head of each cow on d -2. Pedometer results were recorded on d -2 and 0. Estrus expression was defined as removal of >50% of the rub-off coating from the patch on d 0. Net physical activity during estrus was calculated by subtracting total steps from d -4 to -2 (nonestrus basal activity) from total steps from d -2 to 0 (proestrus + estrus period) of each cow. Cows that did not express estrus were classified as NOESTR. Cows that expressed estrus were ranked by net physical activity; those above the median were classified as HIESTR and the remaining cows as LWESTR. Ovarian ultrasonography was performed on d 0 and 7. Blood was collected on d 0, 7, 20, and 30. Pregnancy status was verified by ultrasonography on d 30. Only data from cows responsive to the estrus synchronization protocol were utilized (NOESTR, n = 59; LWESTR, n = 100; HIESTR, n = 98). Diameter of dominant follicle on d 0, corpus luteum volume on d 7, and plasma P4 concentrations on d 7 were greater (P ≤ 0.05) in HIESTR vs. LWESTR and NOESTR and also greater (P ≤ 0.05) for LWESTR vs. NOESTR. Plasma P4 concentrations on d 0 were greater (P < 0.01) in NOESTR vs. HIESTR and LWESTR and similar (P = 0.93) between HIESTR and LWESTR. Whole blood mRNA expression of myxovirus resistance 2 on d 20 was greater (P ≤ 0.05) in HIESTR vs. LWESTR and NOESTR, and similar (P = 0.72) between LWESTR and NOESTR. Pregnancy rates were less (P ≤ 0.04) in NOESTR vs. HIESTR and LWESTR (52.4%, 68.9%, and 73.5%, SEM = 7.2), and similar (P = 0.57) between HIESTR and LWESTR. Hence, expression of estrus during a timed-AI protocol improved ovarian dynamics and pregnancy success, whereas estrus intensity modulated key biological markers associated with fertility but not pregnancy rates in B. indicus-influenced cows beef cows.

Safe core-satellite magneto-plasmonic nanostructures for efficient targeting and photothermal treatment of tumor cells.

Magneto-plasmonic nanostructures functionalized with cell targeting units are of great interest for nanobiotechnology applications. Photothermal treatment of cells targeted with antibody functionalized nanostructures and followed by magnetic isolation, allows killing selected cells and hence is one of the applications of great interest. The magneto-plasmonic nanostructures reported herein were synthesized using naked gold and magnetite nanoparticles obtained through a green approach based on laser ablation of bulk materials in water. These particles do not need purifications steps for biocompatibility and are functionalized with a SERRS (surface enhanced resonance Raman scattering) active molecule for detection and with an antibody for targeting prostate tumor cells. Quantitative results for the cell targeting and selection efficiency show an overall accuracy of 94% at picomolar concentrations. The photothermal treatment efficiently kills targeted and magneto-selected cells producing a viability below 5% after 3 min of irradiation, compared with almost 100% viability of incubated and irradiated, but non targeted cells.

Temperature dependence of the nonlinear optical response of smectic liquid crystals containing gold nanorods.

The present study is devoted to the investigation of the nonlinear optical properties of a smectic liquid crystal doped with gold nanorods. Using the Z-scan technique, we investigate the changes in the optical birefringence of a homeotropic sample upon laser exposure, considering the configurations of normal and oblique incidence. Our results reveal that the birefringence variations may be governed by distinct physical mechanisms, depending on the relative angle between the far-field director and the wave vector of the excitation laser beam. In particular, we observe that the position dependence of the far-field transmittance exhibits different behaviors as the incidence angle is changed, indicating that distortions in the beam wavefront may be associated with the thermal lens phenomenon or an optically induced reorientation of the nematic director. The temperature dependence of the nonlinear refractive and absorptive coefficients is investigated close to the smectic-A-nematic phase transition. A detailed analysis of the interplay between smectic order and plasmon resonance is performed, thus unveiling the capability of plasmonic liquid crystal to be used in optical devices.

Design, synthesis, molecular docking and biological evaluation of thiophen-2-iminothiazolidine derivatives for use against Trypanosoma cruzi.

In this study, we designed and synthesized a series of thiophen-2-iminothiazolidine derivatives from thiophen-2-thioureic with good anti-Trypanosoma cruzi activity. Several of the final compounds displayed remarkable trypanocidal activity. The ability of the new compounds to inhibit the activity of the enzyme cruzain, the major cysteine protease of T. cruzi, was also explored. The compounds 3b, 4b, 8b and 8c were the most active derivatives against amastigote form, with significant IC50 values between 9.7 and 6.03µM. The 8c derivative showed the highest potency against cruzain (IC50=2.4µM). Molecular docking study showed that this compound can interact with subsites S1 and S2 simultaneously, and the negative values for the theoretical energy binding (Eb=-7.39kcal·mol(-1)) indicates interaction (via dipole-dipole) between the hybridized sulfur sp(3) atom at the thiazolidine ring and Gly66. Finally, the results suggest that the thiophen-2-iminothiazolidines synthesized are important lead compounds for the continuing battle against Chagas disease.

Thermo-optical properties and nonlinear optical response of smectic liquid crystals containing gold nanoparticles.

The present work is devoted to the study of the thermo-optical and nonlinear optical properties of smectic samples containing gold nanoparticles with different shapes. By using the time-resolved Z-scan technique, we determine the effects of nanoparticle addition on the critical behavior of the thermal diffusivity and thermo-optical coefficient at the vicinity of the smectic-A-nematic phase transition. Our results reveal that introduction of gold nanoparticles affects the temperature dependence of thermo-optical parameters, due to the local distortions in the orientational order and heat generation provided by guest particles during the laser exposure. Further, we show that a nonlinear optical response may take place at temperatures where the smectic order is well established. We provide a detailed discussion of the effects associated with the introduction gold nanoparticles on the mechanisms behind the thermal transport and optical nonlinearity in liquid-crystal samples.

Fixed-time artificial insemination with estradiol and progesterone for Bos indicus cows I: basis for development of protocols.

Five experiments were conducted on commercial farms in Brazil aiming to develop a fixed-time artificial insemination (TAI) protocol that achieved pregnancy rates between 40% and 55% in Bos indicus cows. These studies resulted in the development of the following protocol: insertion of an intravaginal device containing 1.9 g of progesterone (CIDR) plus 2.0mg im estradiol benzoate on Day 0; 12.5mg im dinoprost tromethamine on Day 7 in cycling cows or on Day 9 in anestrous cows; CIDR withdrawal plus 0.5mg im estradiol cypionate plus temporary calf removal on Day 9; TAI (48h after CIDR withdrawal) plus reuniting of calves with their dams on Day 11. Reduced dose of prostaglandin F(2alpha) (PGF(2alpha); 12.5mg im dinoprost tromethamine) effectively caused luteolysis. In cycling cows, fertility was greater when the treatment with PGF(2alpha) was administered on Day 7 than on Day 9, but in anestrous cows, no effects of time of the PGF(2alpha) treatment were found. Estradiol cypionate effectively replaced estradiol benzoate or gonadotropin-releasing hormone as the ovulatory stimulus, reducing labor and cost. In this protocol, CIDR inserts were successfully used four times (9 d each use) with no detrimental effects on fertility.

Fixed-time artificial insemination with estradiol and progesterone for Bos indicus cows II: strategies and factors affecting fertility.

In Experiments 1, 2, and 3, we evaluated the effects of temporary weaning (TW), equine chorionic gonadotropin (eCG), and follicle-stimulating hormone (FSH) treatments on results of a fixed-time artificial insemination (TAI) protocol in postpartum Bos indicus cows. In Experiment 1, treatment with 400 IU eCG or with TW for 48 h consistently improved pregnancy rates (PRs) at TAI, but, in Experiment 2, FSH treatment was less effective than eCG or TW. In Experiment 3, the inclusion of eCG treatment in cows subjected to TW did not improve PRs. We concluded that TW or 400 IU eCG should be included in the TAI protocol in postpartum Bos indicus cows to enhance fertility. In Experiment 4, we used records from heifers and cows treated with the proposed protocol during the 2006-2007 (n=27,195) and 2007-2008 (n=36,838) breeding seasons from multiple locations in Brazil to evaluate factors potentially affecting PRs. Overall PR at TAI was 49.6% (31,786 of 64,033). Pregnancy rate differed (P<0.01) among farm within location (results ranging between 26.8% and 68.0%; P<0.01), cow group within farm, by breed (Bos indicus, 48.3% [26,123 of 54,145]; Bos taurus, 61.7% [3652 of 5922]; and crossbred Bos indicus x Bos taurus, 50.7% [2011 of 3966]), category (nulliparous, 39.6% [2095 of 5290]; suckled primiparous, 45.2% [3924 of 8677]; suckled multiparous, 51.8% [24,245 of 46,767]; and nonsuckled multiparous, 46.1% [1522 of 3299]), body condition score at TAI (< or =2.5, 43.0% [3409 of 7923]; 3.0, 49.6% [18,958 of 38,229]; and > or =3.5, 52.7% [9419 of 17,881]). Days postpartum at beginning of protocol did not affect PR (30 to 60 d, 47.6% [4228 of 8881]; 61 to 90 d, 51.7% [16,325 to 31,572]; and 91 to 150 d, 50.8% [7616 to 14,991]; P>0.1). Pregnancy rate was also consistently affected (P<0.01) by sire (results ranging from 7.2% to 77.3%) and artificial insemination technician (results ranging from 15.1% to 81.8%).

Mês de parição, condição corporal e resposta ao protocolo de inseminação artificial em tempo fixo em vacas de corte primíparas / Calving date, body condition score, and response to a timed artificial insemination protocol in first-calving beef cows

No experimento I, foi avaliada a alteração da condição corporal (CC) pré e pós-parto em 155 novilhas inseminadas para parir de setembro a dezembro. A CC foi avaliada mensalmente no pré e pós-parto, de junho a fevereiro. No experimento II, 538 vacas primíparas foram sincronizadas com o protocolo de inseminação artificial em tempo fixo (IATF) que usou estradiol junto ao dispositivo intravaginal de progesterona (CIDR®). As taxas de ciclicidade, sincronização e concepção foram avaliadas por ultra-som. No experimento I, os animais que pariram primeiro tiveram maior (P<0,001) redução na CC pós-parto. No experimento II, foi observado maior CC (P<0,0001) nos animais com menor número de dias pós-parto, maior (P<0,05) taxa de sincronização nas vacas de melhor CC e aumento (P<0,0001) na taxa de concepção proporcional ao aumento na CC (incremento médio na concepção de seis pontos percentuais para cada 0,25 ponto na CC). Não se deve antecipar a parição de novilhas de corte quando se pretende realizar IATF no início da estação de monta subseqüente.

In experiment I, it was evaluated the body condition score (BCS) change during pre and post-partum in 155 heifers, inseminated to calve from September to December. The BCS was monthly evaluated from June to February, during the pre and post-partum periods. In experiment II, 538 primiparous cows were synchronized with a timed artificial insemination (TAI) protocol which used estradiol associated with an intravaginal progesterone device (CIDR®). The cyclicity, synchronization, and conception rates were evaluated by ultrasound. In experiment I, the animals that calved earlier had higher (P<0.001) reduction on BCS. In experiment II, it was observed higher BCS (P<0.0001) in cows with lower days in post-partum, higher (P<0.05) synchronization rate in cows with a better BCS, and also an increase (P<0.0001) in conception rate as BCS got better (increase in six percentual points in conception for each increase of 0.25 in BCS). Beef heifers should not calve earlier when is planned to submitt these animals to TAI at the beginning of the next breeding season.

Intersubband exciton relaxation dynamics in single-walled carbon nanotubes.

We study exciton (EX) dynamics in single-walled carbon nanotubes (SWNTs) included in polymethylmethacrylate by two-color pump-probe experiments with unprecedented temporal resolution. In the semiconducting SWNTs, we resolve the intersubband energy relaxation from the EX2 to the EX1 transition and find time constants of about 40 fs. The observation of a photoinduced absorption band strictly correlated to the photobleaching of the EX1 transition supports the excitonic model for primary excitations in SWNTs. We also detect in the time domain coherent oscillations due to the radial breathing modes at approximately 250 cm(-1).

[Changes in risk factors for spontaneous abortion in an area with high concentrations of shoe manufacture after a preventive intervention]. / Evoluzione dei fattori di rischio per l'aborto spontaneo in un'area ad alta concentrazione di calzaturifici dopo un intervento di prevenzione.

Risk factors of spontaneous abortion were investigated in two matched case-control studies in 1987-88 and 1997-99. An history of previous abortions significantly increased the risk in both studies. Lifestyle (coffee) and occupational (exposure to organic solvents) factors were associated with a significantly increased risk in the first but not in the second calendar period, following a community intervention with advice given to workers, employers, and physicians; the latter also counseled a greater use of medicines against spontaneous abortion.

Efeito da aplicaçäo de prostaglandina (PGF2alfa) no pós-parto imediato sobre a incidência de retençäo de placenta em vacas de leite / The effect of Prostaglandins (PGF2alpha) injection in the early post partum period on the incidence of retained placenta in dairy cows

Este trabalho teve como objetivo avaliar o efeito da aplicaçäo de prostaglandina na primeira hora pós-parto sobre a incidência de retençäo de placenta 8 e 12 horas pós-parto. Foram utilizadas 82 vacas como controle e 82 vacas tratadas com 25mg de prostaglandina (LUTALYSEr, 5ml). Vacas tratadas com PGF2a liberaram a placenta mais rápido (P<0,10) do que as näo tratadas (7,72ñ0,84 vs. 10,07ñ1,09h). A incidência de retençäo de placenta com mais de oito horas foi 30,5 por cento no grupo-controle e 17,1 por cento no grupo-tratado (P<0,05) e com mais de 12 horas, 19,5 por cento no grupo-controle e 12,2 por cento no grupo-tratado (P<0,10). Verificou-se também que fazenda, índice de condiçäo corporal e ordem de lactaçäo tiveram influência na ocorrência de retençäo de placenta, mas näo se verificou efeito do sexo do bezerro nem da ajuda ao parto. Estes dados mostram que o tratamento com prostaglandina na primeira hora pós-parto pode ser usado como preventivo da retençäo de placenta

Circulating immunoreactive proANP1-30 and proANP31-67 responses to acute exercise.

The circulating immunoreactive atrial natriuretic peptide (C-terminal; alpha-ANP) increases during exercise to become suppressed in the first hours of the recovery. The response of the N-terminal ANP fragments to acute exercise is not known while proANP (31-67) appears to be elevated with chronic exercise. We evaluated the plasma concentrations of the N-terminal ANP fragments (1-30) and (31-67) in oarsmen (n=10) before and after two acute exercise bouts separated by 5 h. As control, measurements were made on a day with no exercise (n=12). At rest, the concentrations of proANP(1-30) and proANP(31-67) were 344+/-42 and 810+/-172 pmol x l(-1), respectively. Half an hour after the first exercise bout, proANP(1-30) was elevated (to 404+/-48 pmol x l(-1); P<0.05) and decreased below the pre-exercise level (to 316+/-41 pmol x l(-1); P<0.05) 4 h into the recovery period. Also, 30 min after the second exercise session, the concentration of proANP(1-30) was elevated to 408+/-45 pmol x l(-1) (P<0.05) and the pre-exercise level was re-established on the following morning. Thus, proANP(1-30), rather than proANP(31-67), responded to acute exercise. These results suggest that atrial distension and, therefore, the central blood volume changes markedly in athletes during a day with repeated exercise bouts.

Biological variability in assessing the clinical value of biochemical markers of bone turnover.

Analytical and biological variability of three bone markers, deoxypyridinoline (DPD), CrossLaps (CTx) and galactosylhydroxylysine (GHYL) were compared. From 14 healthy subjects (six women, eight men; age 29-44 years) recruited from our laboratory staff, two sets of samples of early morning urine were obtained - four samples taken weekly for 4 weeks (all subjects) and three samples taken monthly for 3 months from five subjects. Data were expressed as the ratio to creatinine concentration. All the methods met the analytical goals (CV(A)< or =1/2CV(I(within-subject))) DPD 0.06, CTx 0.05 and GHYL 0.07 with CV(I(within-subject)) being 0.22, 0.19 and 0.38, respectively. The reference values were of limited usefulness particularly for CTx and GHYL, the index of individuality (II) being 0.50 and 0.48 respectively. As the index of heterogeneity (IH) was not significant, being 0.23 for CTx, 0.28 for DPD and 0.46 for GHYL, which are all <1.71 (1+2S.D.), within-subject variances can be used to calculate the reference change value (RCV): 0.58 for DPD, 0.54 for CTx and 1. 08 for GHYL. Moreover, we found constant variations in DPD and CTx, week to week and month to month. Our findings suggest that DPD and CTx provide more reliable results than GHYL, showing a lower within-subject variation, a lower and time-constant RCV allowing reliable monitoring without regard for timing.

Circulating immunoreactive proANP(1-30) and proANP(31-67) in sedentary subjects and athletes.

BACKGROUND: Atrial natriuretic peptide (ANP) is synthesized and stored in myocytes as prohormone(1-126), which upon release is cleaved into proANP(1-98) and alpha-ANP(99-126). In addition, cleavage of proANP(1-98) produces proANP(1-30), proANP(31-67), and proANP(79-98) fragments. ProANP(1-30) and proANP(31-67) have roles in fluid and electrolyte homeostasis. The aim of the present study was to develop a plasma assay for proANP(1-30) and proANP(31-67) and to compare results in trained athletes and sedentary subjects. METHODS: Two competitive enzyme immunoassays were established with affinity-purified sheep antiserum against synthetic ANP fragments. The immunoreactivity (ir) of proANP(1-30) and proANP(31-67) was measured in 10-microL plasma samples without extraction in a microwell-based assay. Plasma concentrations in sedentary male subjects (n = 22) and male endurance athletes (n = 14) were examined. RESULTS: In the assay for ir-proANP(1-30) and ir-proANP(31-67), the concentrations at 95% B/B(0) were 4.7 and 14.2 pmol/L, respectively. Within-run CVs were 4-6% and 5-6%, and between-run CVs were 9% for both assays. Both assays were linear on dilution (y = 0.9945x - 0. 7291 and y = 1.0001x - 3.428), and the recoveries were 102-112% and 102-106%, respectively. In the sedentary and athletic groups, the ir-proANP(1-30) concentrations were similar: 318 +/- 38 pmol/L and 312 +/- 25 pmol/L (mean +/- SE), respectively, whereas the ir-proANP(31-67) was higher in the rowers (713 +/- 81 pmol/L) than in the sedentary subjects (387 +/- 71 pmol/L; P <0.005). CONCLUSIONS: The proANP fragment assays are precise (CV <10%) and exhibit nearly quantitative recovery (102-112%). Only ir-proANP(31-67) responds to physical training.

Immunoturbidimetric assay of glycated hemoglobin.

We investigated the performances of HbA1c determination by a latex enhanced turbidimetric immunoassay using the specific monoclonal antibodies (Unimate, Roche) against the beta-N-terminal fragments. The coefficients of variation ranges from 1.7 to 3.8% within assay (n = 30) and from 3.9 to 4.9% between assay (n = 20). The assay was linear from 2.5 to 14.9% of HbA1c. No interferences was found from fetal, carbamylated, or variant (S) hemoglobins and from labile Schiff adduct with glucose. The following relationship was derived from fresh sample comparison between HPLC (Diamat-BioRad) (x) and immunoassay (y) method: y = 0.971 x + 0.87%, r=0.98, n = 115. The immunoassay provides a highly precise and specific method for HbA1c.