The effect of downstream plasma treatments on graphene surfaces

This paper reports on the effects of growth, transfer and annealing procedures on graphene grown by chemical vapour deposition. A combination of Raman spectroscopy, electrical measurements, atomic force microscopy, and X-ray photoemission spectroscopy allowed for the study of inherent characteristics and electronic structure of graphene films. Contributions from contaminants and surface inhomogeneities such as ripples were also examined. A new cleaning and reconstruction process for graphene, based on plasma treatments and annealing is presented, opening a new pathway for control over the surface chemistry of graphene films. The method has been successfully used on contacted graphene samples, demonstrating its potential for in situ cleaning, passivation and interface engineering of graphene devices.     

Effect of pregrazing herbage mass and pasture allowance on the lactation performance of Holstein-Friesian dairy cows

The objective of this study was to investigate the effect of pregrazing herbage mass (HM) and pasture allowance (PA) on the grazing management and lactation performance of spring-calving dairy cows. Sixty-eight Holstein-Friesian dairy cows (mean calving date, February 6) were randomly assigned across 4 treatments (n = 17) in a 2 × 2 factorial arrangement. The 4 treatments consisted of 2 pregrazing HM (>4 cm) and 2 PA (>4 cm): 1,700 kg of dry matter (DM)/ha (medium, M) or 2,200 kg of DM/ha (high, H), and 16 or 20 kg of pasture DM/cow per day. The experimental period lasted 30 wk. The experimental area was divided into 4 farmlets, with 1 farmlet per treatment. Mean HM throughout the experimental period was 1,767 kg of DM/ha (M HM) compared with 2,358 kg of DM/ha (H HM). Offering an M HM sward resulted in significantly greater milk protein yield (+31.7 g/d) and lower mean body weight (−12.8 kg). The body condition score change was significantly smaller (−0.21) with the M HM treatments compared with the H HM treatment (−0.34). Milk solids output per hectare was 6% greater on the M HM treatments compared with the H HM treatments. Increasing PA significantly increased milk (+0.9 kg/d), solids-corrected milk (+0.7 kg/d), protein (+43.9 g/d), and lactose (+52.7 g/d) yields. Mean body weight was also significantly greater for cows offered 20 kg of PA (+11.4 kg/cow). It was concluded that in rotational grazing systems, adapting the concept of grazing M HM pastures (1,700 kg of DM/ha) will result in increased sward quality and increased milk solids output per hectare. At medium levels of pregrazing HM, offering animals 20 kg of DM PA will result in increased milk yield per cow.     

Test cell analysis of the use of a supply air window as a passive solar component

A series of experiments was conducted to determine the performance characteristic of a ‘double’ window used to pre-heat background room ventilation. A theoretical model of heat exchange conditions within the window was compared with results from a test cell. The test cell was used in different modes, firstly free-ventilated with the service room window and interconnecting duct to the cell left open, and then with forced ventilation at a consistent velocity to analyse the relative extent of direct solar and ventilation heat gain. A subsidiary study sought to determine the frequency of positive and negative air flow through trickle vents under real house conditions, this was compared with glass temperatures from the test cell measurements to assess the risk of condensation forming within the window. By reference to recent work on ventilated PV systems it was possible to derive a method of relating the U value and Solar Heat Gain Coefficient within the window cavity to a range of boundary conditions.     

Accelerated solvent extraction of animal feedingstuffs for microbial growth inhibition screening for the presence of antimicrobial feed additives

Three plate systems (combinations of indicator organism and growth medium) were evaluated for the detection of analytical standards of the banned feed additives avoparcin, bacitracin zinc, spiramycin, tylosin and virginiamycin. When authorized in the EU, the previously recommended minimum inclusion rate (MIR) for each compound was 5 mg kg^-1. One of the plate systems (Micrococcus luteus ATCC 10240, nutrient agar) detected all five additives. This plate was used in a further study that evaluated the suitability of accelerated solvent extraction (ASE) as a first step in the development of a rapid single-plate screening assay. A drug-free (negative control) feedingstuff was fortified with the compounds (0-50 mg kg^-1), extracted by ASE and the extracts applied to the plate at each of three pH ranges - unadjusted extract (pH 5.7-5.9), pH 6.5 and 8.0. At pH 6.5, sub-MIR concentrations of virginiamycin and tylosin were detectable. Avoparcin was detectable at 6.3 mg kg^-1. The detection of zinc bacitracin was pH-independent (10 mg kg^-1). At pH 8.0, spiramycin was detectable at 5.4 mg kg^-1. Mean ±SD analytical recoveries from fortified feedingstuffs (n = 10) ranged from 57 ±1.5% for avoparcin to 96 ±4% for virginiamycin. The five additives were also detectable following ASE extraction from a range of different feedingstuffs fortified with each of the drugs. A further 24 compounds permitted for use in animal feeds were tested. Of these, nine were detectable at their recommended MIR. It is concluded that ASE is a versatile technique suitable for the automated extraction of a range of antimicrobials from animal feedingstuffs. Employing ASE with this single-plate detection system permits the rapid antimicrobial screening of animal feedingstuffs and allows the detection of the banned additives. Whilst the method is applicable as a screening test, more specific postscreening methods would be necessary for subsequent identification (and quantification) of antimicrobials in screening-positive samples.     

Cross-contamination of lettuce (Lactuca sativa L.) with Escherichia coli O157:H7 via contaminated ground beef

A lettuce outbreak strain of E. coli O157:H7 was used to quantitate the pathogen's survival in ground beef and its transfer to hands, cutting board surfaces, and lettuce. Overnight storage of inoculated beef at 4 degrees C resulted in no pathogen growth, while room-temperature storage allowed multiplication. Hamburger patty formation allowed the transfer of bacteria to hands. Contaminated fingers subsequently transferred the pathogen to lettuce during handling. E. coli was transferred from hamburgers to cutting board surfaces; overnight storage of boards decreased the numbers of recoverable pathogens by approximately 1 log CFU. A 15-s water rinse failed to remove significant numbers of pathogens from cutting boards whether it was applied immediately after contamination or following overnight room-temperature storage. Three lettuce leaves were successively applied to a single contaminated cutting board area both immediately after contamination and after overnight room-temperature storage of contaminated boards. Another set of leaves was pressed onto boards immediately following contamination and was then stored overnight at 4 degrees C before pathogen enumeration. The numbers of pathogens transferred to the first pressed leaves were larger than those transferred to the second or third leaves. There were no significant differences in the numbers of pathogensrecovered from leaves pressed immediately after contamination whether pathogens were enumerated immediately or following overnight storage at 4 degrees C. However, fewer pathogens were transferred to leaves pressed to boards stored overnight at room temperature prior to contact with lettuce. Twenty-five lettuce pieces were successively pressed onto one area on a board containing 1.25 x 10(2) CFU of E. coli. Pathogens were transferred to 46% of the leaves, including the 25th exposed leaf.     

Dual-energy X-ray absorptiometry of the pig: Protocol development and evaluation

As part of a prospective study in bone mineralisation in adult pigs it was necessary to establish guidelines and to define sites for bone mineral measurements. Particular requirements were that, the protocol should be suitable for a mass screening programme in both postmortem specimens and in live animals, and should deliver results of known reliability. Estimates of bone mineral content (BMC) and bone mineral density (BMD) in areas within the 4th metacarpal bone yielded coefficients of variation (CV) in the order of 7% for both regions and estimates in regions which included the entire metacarpal-phalangeal area yielded CV values in the order of 0.7% and 0.6% for BMC and BMD, respectively. A region of interest taken from the coccygeal vertebrae yielded coefficient of variation values of 3% and 2% for BMC and BMD, respectively. Accuracy of dual-energy X-ray absorptiometry (DXA) was estimated using a standard curve derived from BMC determined by ashing. There was a high correlation between mineral content determined by DXA and by ashing (R(2)=0.99, p<0.0001). The results suggest that the regions used in this study are suitable for use in large, mass screening, prospective studies.     

Leishmaniasis in the United States military

Leishmaniasis is a recurrent health problem for the U.S. and other militaries. Health care workers may be unfamiliar with the risk factors, transmission, clinical features, diagnosis, and treatment of this disease. A team of highly trained specialists is required to properly manage service members with leishmaniasis. Such care is available only in a few medical centers. Although there are no prophylactic drugs to prevent this disease, control of insect populations and use of personal protection measures can minimize arthropod-related casualties. The impact of leishmaniasis on military operations and research initiatives to better prevent, diagnose, and treat infection are discussed.     

Response of patients with treatment-refractory schizophrenia to clozapine within three serum level ranges

OBJECTIVE: This study sought to determine the relationships between serum clozapine levels and therapeutic response. METHOD: Fifty-six inpatients who met the DSM-III-R criteria for chronic schizophrenia and who had not responded to extended treatment with classical antipsychotics were randomly assigned to 12 weeks of double-blind treatment with clozapine at one of three serum level ranges: low (50-150 ng/ml), medium (200-300 ng/ml), or high (350-450 ng/ml). Baseline clinical assessments were completed before the patients' regular antipsychotic and anticholinergic drugs were discontinued. During clozapine treatment, serum levels were ascertained weekly to allow adjustment of clozapine doses so as to maintain each patient near the midpoint of his or her assigned serum level range. Clinical assessments were completed after 6 and 12 weeks of treatment. RESULTS: The analyses of the results of treatment supported the superior efficacy of the 200-300 ng/ml and 350-450 ng/ml serum clozapine level ranges over the 50-150 ng/ml range, with no advantage for 350-450 ng/ml over 200-300 ng/ml. Sleepiness increased with increasing serum levels. CONCLUSIONS: Serum clozapine levels per unit of daily dose were at the lower end of the range noted in previous reports, possibly reflecting the current study's dosing schedules of twice or three times a day, the 11- to 13-hour postdose sampling time, and the moderate doses given. Serum clozapine levels, if interpreted in relation to daily clozapine dosing schedules, postdose sampling time, and total daily dose, may help to guide dosing to provide adequate opportunities for therapeutic response and to limit certain side effects of clozapine treatment.     

Metabolic control and quality-of-life self-assessment in adolescents with IDDM

A 67-year-old man was diagnosed as having a type 3 advanced esophageal carcinoma by barium swallow and endoscopy. Biopsy specimens showed well-differentiated squamous cell carcinoma with positive immunostaining for p53, C-erb B-2 and negative for bcl-2. Two courses of chemotherapy using 5-FU, leucovorin and CDDP were performed before operation. Because no cancer cells were present in the surgical specimens, the effect was evaluated as grade 3. This neoadjuvant chemotherapy may be effective for esophageal carcinoma with a possible apoptosis mechanism.