Unexpected catalytic activity of nanorippled graphene.

Graphite is one of the most chemically inert materials. Its elementary constituent, monolayer graphene, is generally expected to inherit most of the parent material's properties including chemical inertness. Here, we show that, unlike graphite, defect-free monolayer graphene exhibits a strong activity with respect to splitting molecular hydrogen, which is comparable to that of metallic and other known catalysts for this reaction. We attribute the unexpected catalytic activity to surface corrugations (nanoscale ripples), a conclusion supported by theory. Nanoripples are likely to play a role in other chemical reactions involving graphene and, because nanorippling is inherent to atomically thin crystals, can be important for two-dimensional (2D) materials in general.

Isotopic Control of the Boron-Vacancy Spin Defect in Hexagonal Boron Nitride.

We report on electron spin resonance (ESR) spectroscopy of boron-vacancy (V_{B}^{-}) centers hosted in isotopically engineered hexagonal boron nitride (hBN) crystals. We first show that isotopic purification of hBN with ^{15}N yields a simplified and well-resolved hyperfine structure of V_{B}^{-} centers, while purification with ^{10}B leads to narrower ESR linewidths. These results establish isotopically purified h^{10}B^{15}N crystals as the optimal host material for future use of V_{B}^{-} spin defects in quantum technologies. Capitalizing on these findings, we then demonstrate optically induced polarization of ^{15}N nuclei in h^{10}B^{15}N, whose mechanism relies on electron-nuclear spin mixing in the V_{B}^{-} ground state. This work opens up new prospects for future developments of spin-based quantum sensors and simulators on a two-dimensional material platform.

Combinatorial ASO-mediated therapy with low dose SMN and the protective modifier Chp1 is not sufficient to ameliorate SMA pathology hallmarks.

Spinal muscular atrophy (SMA) is a devastating genetically inherited neuromuscular disorder characterized by the progressive loss of motor neurons in the spinal cord, leading to muscle atrophy and weakness. Although SMA is caused by homozygous mutations in SMN1, the disease severity is mainly determined by the copy number of SMN2, an almost identical gene that produces ~10% correctly spliced SMN transcripts. Recently, three FDA- and EMA-approved therapies that either increase correctly spliced SMN2 transcripts (nusinersen and risdiplam) or replace SMN1 (onasemnogen abeparvovec-xioi) have revolutionized the clinical outcome in SMA patients. However, for severely affected SMA individuals carrying only two SMN2 copies even a presymptomatic therapy might be insufficient to fully counteract disease development. Therefore, SMN-independent compounds supporting SMN-dependent therapies represent a promising therapeutic approach. Recently, we have shown a significant amelioration of SMA disease hallmarks in a severely affected SMA mouse carrying a mutant Chp1 allele when combined with low-dose of SMN antisense oligonucleotide (ASO) treatment. CHP1 is a direct interacting partner of PLS3, a strong protective modifier of SMA. Both proteins ameliorate impaired endocytosis in SMA and significantly restore pathological hallmarks in mice. Here, we aimed to pharmacologically reduce CHP1 levels in an ASO-based combinatorial therapy targeting SMN and Chp1. Chp1 modulation is a major challenge since its genetic reduction to ~50% has shown to ameliorate SMA pathology, while the downregulation below that level causes cerebellar ataxia. Efficacy and tolerability studies determined that a single injection of 30 µg Chp1-ASO4 in the CNS is a safe dosage that significantly reduced CHP1 levels to ~50% at postnatal day (PND)14. Unfortunately, neither electrophysiological predictors such as compound muscle action potential (CMAP) or motor unit number estimation (MUNE) nor histological hallmarks of SMA in neuromuscular junction (NMJ), spinal cord or muscle were ameliorated in SMA mice treated with Chp1-ASO4 compared to CTRL-ASO at PND21. Surprisingly, CHP1 levels were almost at control level 4-weeks post injection, indicating a rather short-term effect of the ASO. Therefore, we re-administrated Chp1-ASO4 by i.c.v. bolus injection at PND28. However, no significant improvement of SMA hallmarks were seen at 2 month-of-age either. In conclusion, in contrast to the protective effect of genetically-induced Chp1 reduction on SMA, combinatorial therapy with Chp1- and SMN-ASOs failed to significantly ameliorate the SMA pathology. Chp1-ASOs compared to SMN-ASO proved to have rather short-term effect and even reinjection had no significant impact on SMA progression, suggesting that further optimization of the ASO may be required to fully explore the combination.

Characterizing the diagnostic sensitivity and specificity of pain biomarkers in cattle using receiver operating characteristic curves.

Biomarkers are used to assess pain and analgesic drug efficacy in livestock. However, often the diagnostic sensitivity and specificity of these biomarkers for different painful conditions over time have not been described. Receiver operating characteristic (ROC) curves are graphical plots that illustrate the diagnostic ability of a test as its discrimination threshold is varied. The objective of this analysis was to use area under the curve (AUC) values derived from ROC analysis to characterize the predictive value of potential pain biomarkers at specific time points following a painful stimulus. The biomarkers included in the analysis were plasma cortisol, salivary cortisol, hair cortisol, infrared thermography (IRT), mechanical nociceptive threshold (MNT), substance P, kinematic gait analysis, and a visual analog scale for pain. A total of 7,992 biomarker outcomes collected from 7 pain studies involving pain associated with castration, dehorning, lameness, and abdominal surgery were included in the analysis. Each study consisted of 3 treatments: uncontrolled pain (tissue damage), no pain (handled controls), and analgesic use (tissue damage, administered a nonsteroidal anti-inflammatory drug). Results comparing analgesic effects to uncontrolled pain consistently yielded AUC values >0.7 (95% confidence interval: 0.40 to 0.99) for plasma cortisol (time points: 1.5, 2, 3, 4, 6, and 8 h), hair cortisol (time point: 62 d), and IRT (time point: 72 h). Results comparing analgesic effects to uncontrolled pain consistently yielded AUC values <0.7 (95% confidence interval: 0.28 to 0.90) for salivary cortisol (6, 13, 20, 34, 48, and 62 d); MNT (6, 25, and 49 h); substance P (1, 2, 3, 4, 6, 8, 12, 18, 24, 48, 72, 96, 120, 144, 312, 480, 816, 1,152, and 1,488 h); kinematic gait analysis including area (8, 16, 48, 72, 96, and 120 h), force (8, 16, 24, 48, 72, 96, and 120 h), and pressure (8, 16, 24, 48, 72, 96, and 120 h); and a visual analog scale for pain (1, 2, 3, 4, 5, and 6 d). These results indicate that ROC analysis can be used to characterize the predictive value of pain biomarkers and provide new knowledge on the diagnostic accuracy of pain biomarkers within this data set. This analysis, using data from 7 studies, was a preliminary approach to identify biomarkers and collection time points that could inform additional analytical approaches or meta-analyses with larger sample sizes, which are needed to further validate these hypotheses and conclusions.

Genetic heterogeneity in Pakistani microcephaly families.

Autosomal recessive primary microcephaly (MCPH) is caused by mutations in at least eight different genes involved either in cell division or DNA repair. Most mutations are identified in consanguine families from Pakistan, Iran and India. To further assess their genetic heterogeneity and mutational spectra, we have analyzed 57 consanguine Pakistani MCPH families. In 34 MCPH families, we detected linkage to five out of the eight well-characterized disease loci and identified mutations in 27 families, leaving seven families without mutations in the coding exons of the presumably underlying MCPH genes. In the MCPH cohort 23 families could not be linked to any of the known loci, pointing to remarkable locus heterogeneity. The majority of mutations were found in ASPM followed by WDR62, CENPJ, CEP152 and MCPH1. One ASPM mutation (p.Trp1326*) was found in as many as eight families suggesting a Pakistani founder mutation. One third of the families were linked to ASPM followed by WDR62 confirming previous data. We identified three novel ASPM mutations, four novel WDR62 mutations, one novel MCPH1 mutation and two novel CEP152 mutations. CEP152 mutations have not been described before in the Pakistani population.

Negative-U system of carbon vacancy in 4H-SiC.

Using electron paramagnetic resonance (EPR), energy levels of the carbon vacancy (V(C)) in 4H-SiC and its negative-U properties have been determined. Combining EPR and deep-level transient spectroscopy we show that the two most common defects in as-grown 4H-SiC--the Z(1/2) lifetime-limiting defect and the EH(7) deep defect--are related to the double acceptor (2-|0) and single donor (0|+) levels of V(C), respectively.

InGaN quantum dot formation mechanism on hexagonal GaN/InGaN/GaN pyramids.

Growing InGaN quantum dots (QDs) at the apex of hexagonal GaN pyramids is an elegant approach to achieve a deterministic positioning of QDs. Despite similar synthesis procedures by metal organic chemical vapor deposition, the optical properties of the QDs reported in the literature vary drastically. The QDs tend to exhibit either narrow or broad emission lines in the micro-photoluminescence spectra. By coupled microstructural and optical investigations, the QDs giving rise to narrow emission lines were concluded to nucleate in association with a (0001) facet at the apex of the GaN pyramid.

Effect of a single dose of meloxicam prior to band or knife castration in 1-wk-old beef calves: I. Acute pain.

In Western Canada, approximately half of the calves produced are castrated before 1 wk of age. Therefore, it is important to identify effective analgesic drugs to mitigate pain associated with castration and consequently improve animal welfare. The aim of this study was to assess the efficacy of a single s.c. dose of meloxicam at mitigating pain associated with knife and band castration in 1-wk-old calves. Seventy-two Angus crossbred bull calves (47.3 ± 6.70 kg of body weight (BW), 1 wk old) were used in a 3 × 2 factorial design where main factors included castration method-sham (CT), band (BA) or knife (KN) castration- and medication-lactate ringer (NM) or 0.5 mg/kg BW of meloxicam (M). Measurements included different physiological and behavioral parameters. Samples were collected on day -1, immediately before castration (T0); and 60, 90, and 120 min and 1, 2, 3, and 7 d after castration except for visual analog scale (VAS) which was collected at the time of castration. The salivary cortisol concentrations were greater (P = 0.04) in KN and BA calves than CT calves 60 min after castration, while 90 min after castration BA had greater concentrations than CT calves. Substance P concentrations were greater (P = 0.04) in NM calves than M calves on d 3 and 7 after castration. The serum amyloid-A (SAA) concentrations were greater (P = 0.05) in KN calves than BA and CT calves on days 0, 2, and 3, while BA calves had greater SAA concentrations on day 7 than KN and CT calves. The visual analog scores were greater (P < 0.01) in KN calves than BA, and in BA compared to CT calves. The KN calves tail flicked more (P < 0.01) than BA and CT calves, and NM calves tail flicked more (P = 0.03) than M calves. No castration or medication effect (P > 0.10) was observed for stride length, walking, standing, lying ventral, eating, foot stamping, head turning, lying and standing percentage, performance, platelets, or body temperature. Overall, knife castrated calves exhibited a greater acute pain response than band castrated calves. Meloxicam was able to reduce substance P concentrations, white blood cell counts and number of tail flicks after castration, suggesting that the drug was able to mitigate acute pain to some extent. However, meloxicam did not have an effect on the other physiological and behavioral parameters assessed.

Effect of band and knife castration of beef calves on welfare indicators of pain at three relevant industry ages: II. Chronic pain.

Three experiments were conducted to evaluate the effects of band and knife castration on behavioral and physiological indicators of chronic pain in beef calves at 3 different ages (36 calves/age group): 1 wk of age (Exp. 1, 4 ± 1.1 d of age, 43 ± 1.1 kg BW), 2 mo of age (Exp. 2, 63 ± 2.3 d of age, 92 ± 1.7 kg BW), and 4 mo of age (Exp. 3, 125 ± 4.6 d of age, 160 ± 3.4 kg BW). In each experiment calves were randomly assigned to either sham (CT), band (BA) or knife (KN) castration. Experiments 1, 2, and 3 ended when the testicles of banded calves had sloughed off (68, 49, and 42 d, respectively). Animal BW and rectal temperature were recorded weekly over the experimental period. Salivary cortisol, substance P, haptoglobin, scrotal area temperature using infrared thermography, visual evaluation of swelling (5-point scale), and gait stride length were collected on d -1 and immediately before castration and weekly thereafter until the end of the study. Hair samples were collected 1 d prior to and 28 d after castration and at the end of the study for cortisol concentration. Standing and lying behaviors were recorded over a 28-d period immediately after castration. No differences ( > 0.10) were observed in salivary cortisol, substance P, haptoglobin, or hair cortisol among castration methods for any of the 3 ages. No changes in behavior were observed in calves castrated at 1 wk or 2 mo of age. In 4 mo-old-calves, BA spent less time lying ( < 0.01) than CT and KN calves. Also, the average duration of lying time for BA calves was greater ( < 0.05) than for CT calves. Both, 1-wk- and 2-mo-old calves had inflammation in the scrotal area lasting 7 d after KN castration, whereas inflammation was observed for up to 14 d in 4-mo-old calves. Swelling in BA calves lasted for 21 to 28 d in the 2 younger groups of calves, whereas in 4-mo-old calves swelling was observed until d 35 postcastration. Knife- and band-castrated calves did not exhibit indicators of chronic pain or distress when the procedures were performed in calves younger than 2 mo of age. Therefore, pain mitigation should be used when castrating to improve animal welfare, especially when castrations are performed in calves older than 2 mo of age independent of the method of castration.

Effect of band and knife castration of beef calves on welfare indicators of pain at three relevant industry ages: I. Acute pain.

Three experiments evaluated the effect of band and knife castration on acute pain for the first 7 d after the procedure on 1-wk-, 2-mo-, and 4-mo-old calves. All calves were blocked by age and weight and randomly assigned to 1 of 3 treatments: sham castration (control, CT), band castration (BA), and knife castration (KN). Experiment 1 evaluated 1-wk-old Angus bull calves ( = 34; 43.0 ± 6.61 kg BW), Exp. 2 evaluated 2-mo-old Angus bull calves ( = 34; 91.5 ± 11.93 kg BW), and Exp. 3 evaluated 4-mo-old Angus bull calves ( = 35; 157.6 ± 22.52 kg BW). For all experiments, physiological and behavioral parameters were collected before (d -1 and immediately before castration [T0]) and after (60 and 120 min and on d 7) castration to assess acute pain. Physiological measures included complete blood cell count, cortisol, substance P, and scrotal temperature. Behavioral measures consisted of a visual analog scale, stride length, and time and frequency budgets for walking, standing, lying, tail flicking, foot stamping, and head turning. Performance parameters included initial and final BW and ADG. In Exp. 1, tail flicking was greater ( = 0.02) in KN calves compared to BA calves 2 to 4 h after castration, although no differences were seen between BA and KN compared to CT calves. In Exp. 2, a treatment × time interaction ( = 0.02) was observed for cortisol, where KN calves had greater cortisol concentrations 120 min after castration compared to BA and CT calves; KN calves also lay down and ate less ( < 0.01; = 0.02) and stood and walked more ( < 0.01; = 0.05) compared to BA and CT calves 2 to 4 h after castration. In Exp. 3, a treatment × time interaction ( < 0.01) was observed for cortisol concentrations in which all treatments were different from one another at 60 and 120 min, with BA calves having the greatest concentrations, KN calves being intermediate, and CT having the lowest concentrations. Overall, KN and BA castrated calves presented physiological and behavioral changes associated with acute pain; however, 2-mo-old BA calves presented the fewest behavioral changes and no physiological changes associated with acute pain compared to CT calves.

Effect of timing of subcutaneous meloxicam administration on indicators of pain after knife castration of weaned calves.

The newly revised Canadian Codes of Practice for the management of beef cattle requires that as of 2018, calves older than 6 mo of age be castrated using pain control. Castration is a husbandry procedure commonly done without pain control, and there is a lack of agreement on an effective pain mitigation strategy specific to castration. The aim of this study was to identify the optimal time of administration of meloxicam prior to castration. Thirty-four Angus and Angus crossbred bull calves (282 ± 28.0 kg BW) were randomly assigned to 1 of 3 treatments receiving a single s.c. injection of meloxicam (0.5 mg/kg BW): 6 h (6H; = 11), 3 h (3H; = 12), or immediately (0H; = 11) before knife castration. Measurements included visual analog scale (VAS), head movement (HM), accelerometer movement (AM) and strain gauge exertion force (EF) on the squeeze chute, stride length (SL), lying and standing behavior, salivary cortisol (SC), haptoglobin, serum amyloid A (SAA), substance P (SP), and scrotal temperature (ST). Samples were collected on d -7, -5, -2, -1, and immediately before castration (T0) and 30, 60, 120, and 240 min and 1, 2, 5, 7, 14, 21, and 28 d after castration, except for VAS, AM, EF, and HM, which were obtained at the time of castration. A time × treatment effect ( = 0.01) was observed for SP, where 0H had lower concentrations than 3H and 6H calves 1 d after castration, whereas 3H calves tended to have greater levels than 6H calves 5 d after castration. Mean ST was greater ( < 0.01) in 6H calves compared to 0H and 3H calves 120 min after castration, whereas 6H and 3H calves had greater ST compared to 0H calves 240 min after castration. On d 1 after castration, 6H calves had greater ST than 0H and 3H calves, whereas 0H calves had greater ST compared to 3H and 6H calves on d 28 after castration. The SL tended ( = 0.09) to be shorter in 3H and 6H calves than 0H calves 30, 60, 120, and 240 min after castration. Number of peaks from the AM between 2 and 3 SD above or below the mean were greater ( = 0.03) in 3H and 6H calves than in 0H calves. No treatment differences ( > 0.10) were observed for the number of peaks and area for AM and EF, VAS, HM, SC, or haptoglobin. On the basis of these results, the optimal time to administer s.c. meloxicam in 7- to 8-mo-old knife-castrated calves is immediately before castration (0H), as evidenced by fewer indicators of pain and inflammation compared to 3H and 6H calves.

Enhancement of carbon tetrachloride-induced liver injury by a single dose of ethanol: proton magnetic resonance imaging (MRI) studies in vivo.

Magnetic resonance imaging (MRI) and localized magnetic resonance spectroscopy (MRS) were used to study the effects of a single dose of ethanol, given 18 h prior to experiments, on CC14-induced acute hepatotoxicity in rats in situ. Localized edema in the centrilobular region of the liver, following exposure to ethanol and CCl4, was detected by 1H-MRI techniques. The edema was characterized by a volume selective spectroscopy (VOSY) method, which measured an increase in water concentration from ethanol and CCl4-treated rat livers, in comparison to control livers. Electron microscopy (EM) of the high intensity regions of the ethanol/CCl4 treated liver sections revealed dramatic subcellular changes such as fragmentation of the granular endoplasmic reticulum (ER), formation of large vacuoles and lipid droplets in the cytoplasmic matrix and extensive swelling of the mitochondria as well as disruption of the cristae. Pretreatment with alpha-phenyl tert-butyl nitrone (PBN), a free radical spin trap, prior to halocarbon exposure, was found to reduce the CC14-mediated high intensity region in the liver images. Electron microscopy of the PBN pretreated CCl4 exposed rat liver sections revealed only minor observable differences in subcellular organization, such as some swelling of the mitochondria, when compared to controls. In addition, these data suggest that ethanol may potentiate CCl4 hepatotoxicity by increased formation of free radical intermediates. Inhibition of the CCl4-induced edematous response in rat liver by PBN demonstrates that free radical intermediates, arising from the metabolism of CCl4, are possibly the causal factor in the initiation of the edema.

In vivo and in vitro 31P-NMR spectroscopy of rat liver treated with halocarbons.

Both in vivo and in vitro 31P-NMR spectroscopy were used to demonstrate metabolic changes in rat liver as a function of time after exposure to either carbon tetrachloride (CCl4) or bromotrichloromethane (BrCCl3). The inorganic phosphate resonance, measured in vivo, moves upfield, which is associated with a decrease in cytosolic pH over a 12 or 20 h period (for BrCCl3 or CCl4, respectively). Intoxication by CCl4 or BrCCl3 causes an intracellular acidosis to pH 7.05 or 6.82 (+/- 0.05), respectively. Also, it has been found that halocarbon exposure increases the amounts of phosphomonoesters (PME) detected. High resolution in vitro 31P-NMR spectroscopy studies of perchloric acid extracts of CCl4-treated rat livers indicated a significant increase in the height of the phosphocholine resonance in the PME region 4-5 h after CCl4 exposure.

Spin-trapping of the trichloromethyl radical produced during enzymic NADPH oxidation in the presence of carbon tetrachloride or bromotrichloromethane.

Utilizing the spin-trapping agent phenyl-t-butyl nitrone, a free radical has been detected which is produced from carbon tetrachloride or bromotrichloromethane during the enzymic oxidation of NADPH by rat liver microsomes. The presence of NADPH is obligatory for generation of the radical. The formation of the trichloromethyl radical-phenyl-t-butyl nitrone adduct is an enzymic process, as evidenced by the inhibition of its formation in systems containing heated microsomes and in systems containing p-hydroxymercuribenzoate. A computer-simulated ESR spectrum for the trichloromethyl adduct of phenyl-t-butyl nitrone can reproduce the essential features of the spectrum of the spin-trapped radical produced enzymically from CCl4. A mechanism is proposed for the formation of the trichloromethyl radical from CCl4 or BrCCl3.

Trailer temperature and humidity during winter transport of cattle in Canada and evaluation of indicators used to assess the welfare of cull beef cows before and after transport.

The current study evaluated 17 loads of cull beef cows transported in Canadian winter conditions to assess in-transit temperature and humidity, evaluation of events during loading and unloading, and animal condition and bruising. Regardless of the use of boards to block ventilation holes in trailers, temperatures were higher within trailers than at ambient locations during both travel and stationary periods (P < 0.01). Boarding was associated with smaller differences in trailer temperature, compared with ambient conditions, while the trailer was traveling at highway speeds versus when trailers were stationary (P < 0.01). Moisture levels within trailers were not different from ambient conditions when loads using boarding were traveling (P < 0.01), whereas loads without boarding had a larger difference (P < 0.01). The moisture within trailers relative to ambient conditions increased when trailers were stationary compared with traveling when boarding was used (P < 0.01). The majority of cattle transported were in good body condition (97.4% within BCS of 2 to 3.5) and had calm temperaments (96.7%). Although all comparisons were made, only the doghouse compartment had an increased risk of severe bruising compared with all other compartments (odds ratio [95% confidence interval]: 3.0 [1.6­5.5], 3.7 [2.1­6.4], 2.2 [1.3­3.7] and 3.8 [1.5­9.6] in comparison with the back, belly, deck, and nose compartments, respectively; P < 0.05). Increasing the duration of waiting to unload 30 min relative to a 1 h duration increased the odds of severe bruising by 1.18 times (95% confidence interval: 1.09­1.29; P < 0.01). Scoring systems that have been developed for auditing unloading of cattle had limited variation across loads at both loading and unloading. Pretransport assessment of animal condition using the American Meat Institute's compromised animal score was the only scoring system that was consistent with posttransport scores. We inferred from the temperature and humidity data in the current study that under commercial conditions, boarding may increase ventilation within trailers during travel and decrease ventilation during stationary periods. The current study provides the first indication that issues in Canadian cull cow transport may be related to pretransport animal condition and management of unloading.

Effect of anti-gonadotropin-releasing factor vaccine and band castration on indicators of welfare in beef cattle.

Angus crossbred bulls (n = 60; 257 ± 5.4 d of age; initial BW 358.8 ± 3.78 kg) were used to study the effect of a vaccine against gonadotropin-releasing factor (GnRF) and band castration on behavioral and physiological indicators of pain. Cattle were randomly assigned to 1 of 3 treatments: bulls, band-castrated calves without pain mitigation (castrated), and immune-vaccinated animals administered an anti-GnRF vaccine (vaccinated). All animals were fitted with a radio frequency ear tag so that individual animal feed intake and feeding behavior were recorded daily over the entire trial using an electronic feed bunk monitoring system. Two doses of anti-GnRF vaccine were administrated on d -35 and 0 and band castration was performed on d 0. Animal BW was recorded weekly starting on d -36 until d 56. Visual analog scores (VAS) were measured on d -36 -35, -1, and 0, and salivary cortisol concentration was measured at -30, 0, 30, 60, 120, and 270 min on d -35 and 0 after castration. Saliva and blood were obtained on d 1, 2, 5, and 7 and weekly until d 56 for determination of cortisol and complete blood cell count. Video data were collected for pain, sexual, and aggressive behavior daily the first week and once a week until d 56. Data were analyzed with a mixed-effect model with castration, time, and their interactions as main effects. Vaccinated calves had reduced ADG and intake (P < 0.05 and P < 0.001, respectively) during the first week after vaccination. Band-castrated calves had reduced ADG and intake (P < 0.001) until the end of the study. No differences in salivary cortisol and VAS were observed among groups at d -35 after the first vaccination and before band castration. However, on d 0, castrated cattle had greater cortisol concentrations and VAS (P < 0.05 and P < 0.01, respectively) than bulls and vaccinated animals. Complete blood cell count did not differ (P > 0.05) between treatments on d 0, 1, and 2. At d 56, vaccinated calves had greater (P < 0.05) final BW than band-castrated calves and both had less final BW than bulls. There was no indication that vaccination caused any physiological or behavioral changes indicative of pain. In contrast, band castration resulted in elevated cortisol scores and VAS indicative of a pain response and behavior related to pain (P < 0.001) until d 42 of the study. The present study demonstrates that anti-GnRF vaccine is a viable animal welfare-friendly alternative to traditional band castration in beef cattle under North American feedlot practices.

Stabilities of hydroxyl radical spin adducts of PBN-type spin traps.

The stability of the hydroxyl spin adduct of nine different PBN-type spin traps has been examined in phosphate buffer solutions of various pH. The hydroxyl adduct is produced by short illumination of hydrogen peroxide with UV light in the presence of spin trap and the decay of its EPR signal followed. The stability measured by the half life of the first-order decay is strongly dependent on the pH of the solution and the structure of the aromatic ring used in the trap. All hydroxyl adducts are more stable in acidic media. tert-Butyl hydroaminoxyl is detected as a degradation product of the hydroxyl adduct from all spin traps.

Studies on the stability of oxygen radical spin adducts of a new spin trap: 5-methyl-5-phenylpyrroline-1-oxide (MPPO).

A new spin trap, 5-methyl-5-phenylpyrrolin-1-oxide (MPPO), has been evaluated with respect to the intrinsic stabilities of the hydroxyl and superoxide (or hydroperoxyl) radical spin adducts. Hydroxyl or superoxide radicals were generated using various sources in the presence of MPPO, and the hydroxyl or superoxide radical spin adduct of MPPO was detected by EPR spectroscopy. The time course of spontaneous decay of the EPR signal from hydroxyl or superoxide spin adducts followed first-order kinetics and the half-life was dependent on the pH of the medium. At pH 7.4 the half-life times are 76.4 and 5.7 min for the hydroxyl and hydroperoxyl/superoxide spin adducts, respectively. Structural factors which could influence the decay rates are also discussed.

Identification of 3-MI-derived N-centered radicals obtained from incubation of 3-MI with microsomal-NADPH system by EPR-HPLC spin trapping.

3-Methylindole (3-MI) is a metabolite of tryptophan that causes acute pulmonary edema and emphysema in ruminants when administered orally or intravenously. Electron paramagnetic resonance (EPR) spin-trapping techniques have been used to investigate the in vitro and in vivo formation of free radicals during 3-MI metabolism by goat lung. Utilizing C-phenyl-N-tert-butyl nitrone (PBN), a nitrogen-centered free radical has been detected from 3-MI in goat lung microsomal incubation. The EPR spectrum of the spin adduct is identical to that observed when 3-MI is irradiated with ultraviolet light. The formation of a nitrogen-centered 3-MI free radical is followed by the appearance of a carbon-centered radical in microsomal preparations. The objective of the present study is to prove that the nitrogen-centered radical generated from the 3-MI incubation system is a 3-MI radical utilizing [14C]-3 MI and the EPR-HPLC technique. The HPLC chromatogram includes three peaks that give EPR signals. These peaks are assigned to nitrogen-, oxygen- and carbon-centered radical adducts. The polarity of the three peaks follows the order: carbon-centered radical adduct > oxygen-centered radical adduct > nitrogen-centered radical adduct. The last has a polarity that is weaker than 3-MI. Only the nitrogen-centered peak and the 3-MI peak possessed radioactivity. The retention time of the nitrogen centered radical is the same as the spin adduct generated by 3-MI irradiation with ultraviolet light. These results demonstrate that the nitrogen-centered radical is a 3-MI-PBN spin adduct, and supports the hypothesis that 3-MI-induced lung damage results from activation of 3-MI to a free radical. Also, in this study the stability of the radical spin adducts and the best conditions to produce the radicals in the incubation system was investigated.