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At least 1,531 records · Page 85Linked to original sources
PubMed2000

Improving the refolding yield of interleukin-4 through the optimization of local interactions.

Interleukin-4 (IL-4) is a multifunctional cytokine that plays an important role in the regulation of various immune responses. However, the development of IL-4 or IL-4 variants into potential therapeutic drugs is hindered by the low efficiency of the in vitro refolding process of this protein. In this work, we have investigated the improvement of the refolding yield of IL-4 using two different rational design approaches. The first one is based on the so-called inverse hydrophobic effect and involved the replacement of a solvent exposed, non-conserved, hydrophobic residue (W91) by serine. This led to an increase in stability of 1.4 kcal mol(-1) and shifted the midpoint transition temperature (Tm) from 62 to 70 degrees C. The second approach is based on the stabilization of alpha-helices through the introduction of favorable local interactions. This strategy resulted in the following helix sequence for helix C of IL-4, 68ASAAEANRHKQLIRFLKRLDRNLWGLAG95. The mutant protein was stabilized by 0.5 kcal mol(-1), the Tm shifted to 68 degrees C, and a two-fold increase in the refolding yield was consistently observed. Our results make the large-scale production of IL-4 derivatives economically more viable, suggest that a similar approach can be applied to other related proteins, and may represent a general strategy to improve in vitro refolding yields through the selective optimization of the stability of alpha-helices.

Amino Acid Sequence↗
PubMed2002

Selection of Gongronella butleri strains for enhanced chitosan yield with UV mutagenesis.

This paper describes the selection of Gongronella butleri strains producing higher chitosan yield using UV mutagenesis. We have devised an enzyme-linked immunosorbent assay for the selection of high chitin deacetylase (CDA) yielding strains. Mutant strains M+1, M+2 and M+7 could produce twice the extractable chitosan yield and double the CDA activity, as compared to the wild type strain.

Amidohydrolases↗
PubMed1986

High-yield criteria for urgent cranial computed tomography scans.

We conducted a study to establish high-yield criteria for urgent cranial computed tomography (CT) scanning in both medical and surgical conditions. Patients were scanned on an emergency basis and were entered in the study if they met preestablished criteria. The clinical findings of the 407 patients in this study were correlated with CT findings. The majority were scanned on an emergency basis for the following reasons: trauma, seizures, altered mental status, hemiparesis, headache, and coma. The yield for CT scans that altered patient management was moderate to high for each of the following categories: coma, 46%; trauma, 30%; seizures, 23%; hemiparesis, 22%; and headache, 21%. The yield for altered mental status and reasons outside the established criteria were fairly low, 8% and 7%, respectively. The specific clinical correlation with CT results in each category is discussed.

Brain Diseases↗
PubMed2001

Recruitment of participants for the Estrogen Replacement and Atherosclerosis (ERA) trial. a comparison of costs, yields, and participant characteristics from community- and hospital-based recruitment strategies.

This paper documents recruitment for the Estrogen Replacement and Atherosclerosis trial, a multicenter, placebo-controlled, double-blind angiographic trial of the effects of opposed and unopposed estrogen on coronary atherosclerosis in postmenopausal women (average scheduled duration of follow-up 3.2 years). We compare costs, yields, and participant characteristics between community-based and hospital-based recruitment strategies. We further compare community-based enriched sources (i.e., those that allowed self-selection or targeted women with known health characteristics) and nonenriched sources. Data gathered on potential participants include method of contact, clinical site, eligibility, completion of screening visits, and randomization rates. Demographic data on participants include age, race, education, marital status, and income. Self-reported health status, smoking status, lipid level, ejection fraction as well as history of chest pain, hypertension, and diabetes were recorded at baseline. Recruitment costs were estimated from employee salaries and costs of screening tests and procedures. Yields were compared by clinical site and by method of contact. Enriched sources of recruitment yielded higher percentages of enrolled participants than nonenriched sources. Both types of source resulted in demographically similar participants. Costs of community-based recruitment were less than hospital-based recruitment; however, screening costs were higher. Overall, screening and recruitment averaged $2508 per randomized participant. Control Clin Trials 2001;22:13-25

Aged↗
PubMed1999

Impacts of ozone on the growth and yield of field-grown winter wheat.

Seed of winter wheat (Triticum aestivum L. cv Riband) was sown on 29 August 1992 in eight field plots. Four plots were exposed to elevated ozone (O(3)) concentrations on 16 days between 29 August and 2 October 1992, for 6 h day(-1), and on 27 days between 29 March and 24 August 1993, for 7 h day(-1). Mean daily O(3) concentrations were approximately 30 and 80 nmol mol(-1) in ambient and fumigated plots, respectively. Plants were sampled on 5 November (1992), 14 January, 16 February, 1 April, 25 May, 23 June and 24 August (1993). No visible symptoms of O(3) damage or premature senescence were observed at any time over the course of the experiment. Exposure to elevated O(3) decreased the above ground biomass by reducing plant density and individual plant relative growth rate. However, there was no significant influence of the pollutant on the growth of the root relative to the shoot. Assessment of yield characteristics at the final harvest revealed an O(3)-induced decrease in the number of grains per ear, as a result of fewer grains per spikelet and an increase in the number of infertile florets per spikelet. No significant effects of the pollutant on the number of ears per plant, spikelets per ear, or 1000 grain weight were found. As a result of the combined effects on the number of grains per ear and the decrease in plant density and growth rate, O(3) exposure reduced grain and straw yields (tonnes ha(-1)) by 13 and 8%, respectively. However, no significant change in the partitioning of dry matter between the grain and the straw was observed in fumigated plots. The findings are discussed within the context of United Nation Economic Commission for Europe critical level guidelines for the protection of crop yields, in relation to their application to winter-sown crops.

Journal Article↗
PubMed2003

The quality of life of spouse dementia caregivers: changes associated with yielding to formal care and widowhood.

The focus of the study was the effect on spouse dementia caregivers of relinquishing care. The study used a longitudinal design, in which a group of 150 dementia caregivers were interviewed 2 years apart (designated Time 1 and Time 2), with data collected from both continuing caregivers and those who had relinquished care. The aims were to determine the extent to which changes over time in quality of life differed between continuing caregivers, those who had yielded to formal care, and those who had been widowed; and to examine whether change in quality of life variables was associated with time since yielding to formal care and time since death of the spouse. Quality of life was defined in terms of health status, psychological well-being, and activity participation. All participants were interviewed in their own homes. Three groups of participants were identified at Time 2: those who continued to provide care for their spouses (n=60); those who had yielded their caregiver role by admitting their spouses to permanent residential care (n=53); and those who had admitted their spouses to permanent institutional care, but whose spouse had then died (n=37). Different patterns of quality of life changes were observed between the three groups, with both positives and negatives associated with disengagement from the caregiving role. Positive changes were particularly evident in psychological well-being and activity participation. These findings were discussed in terms of their relevance for a life transitions approach to the relinquishment of caregiving.

Adaptation, Psychological↗
PubMed1979

Influence of virus infection on the leaf protein yield.

Influence of cowpea mosaic virus (CPMV) and common bean mosaic virus (CBMV) infection on the yield of extractable leaf protein of cowpea cvs. Pusa Phaguni, Pusa Barsati, and Yard Long was studied. An increase as well as decrease in the yield of leaf protein concentrate (LPC), due to virus infection, has been observed. CPMV infection increased LPC yield in all the cowpea cvs., but CBMV decreased it in cys. Pusa Phaguni and Yard Long. Variation in percentage of extractable nitrogen and protein in LPC was also notices. However, total N and protein in leaf and LPC were increased due to virus infection, but total sugar and starch decreased.

Carbohydrates↗
PubMed2002

Embryo yield and plasma progesterone profiles in superovulated dairy cows and heifers.

This study was conducted to compare the superovulatory (SOV) response of dairy cows (n=172) and heifers (n=172), with two SOV treatments started at the mid-luteal-phase of the estrus cycle. Donors were randomly treated either with equine chorionic gonadotrophin (eCG) plus neutra-eCG serum (eCG+N group, n=167) or follicle stimulating gonadotrophin (FSH-P group, n=177). No significant differences were observed among groups in the percentage of superovulatory responsive donors (SR donors; corpora lutea (CL) >/=2), the mean number of total ova, fertilized ova and viable embryos recovered. Cows yielded significantly less total ova and less fertilized ova (P<0.05) and tended to yield less viable embryos (P<0.06) than heifers. Plasma progesterone (P4) concentrations (n=135 donors) on the day of PGF(2alpha) (PGF) injection and on the day of SOV estrus were significantly higher (P<0.01) in eCG+N than in FSH-P donors and, the increase between those 2 days was also significantly higher (P<0.05) in group eCG+N than in group FSH-P, suggesting a higher luteotrophic effect of eCG than FSH-P. SR donors had P4 levels significantly higher (P<0.001) than non-SR donors only on day 5 after the SOV estrus and on the day of embryo recovery. Plasma P4 concentrations at 5 days after the SOV estrus and at embryo recovery correlated significantly (r=0.76, P<0.001).Heifers had significantly higher P4 levels than cows at gonadotrophin injection (P<0.01), PGF injection (P<0.001), 5 days (P<0.01) and 7 days (P<0.001) after the SOV estrus. At day 7 after the SOV estrus, P4 concentrations per ova recovered were significantly higher in heifers than in cows (P<0.01). The increase of plasma P4 per ova recovered, between days 5 and 7 after the SOV estrus, was significantly (P<0.01) higher in heifers than in cows. Also, the increase of plasma P4 between injections of gonadotrophin and PGF was significantly higher (P<0.05) in heifers than in cows.These results suggest that heifers have higher plasma P4 concentrations at diestrus (either before or after the SOV treatment) and this is associated with a higher embryo yield and quality, as compared to lactating cows. These higher plasma P4 concentrations reflect not only differences in ovulation rate as well as the competence of the corpus luteum, which is potentialized by gonadotrophin stimulation.

Animals↗
PubMed2001

Is compulsory restriction of tar yield of cigarettes a worthwhile public health policy?

BACKGROUND: Although the notion of a "safe cigarette" has proved an illusion, while people continue to smoke, an issue remains of whether compulsory restriction of tar yield is a worthwhile public health policy. METHODS: The study group was comprised of a random population sample of middle-aged Scottish men and women-3464 smokers of cigarettes with known tar yield at baseline. Tar yields were classified into low (< 10 mg), low/middle (10-14.99 mg), and middle or high (> or = 15 mg), according to standard groupings. Deaths within the study cohort were recorded over a period of 13 years. RESULTS: Among low, low/middle, and middle or high tar smokers, 55 (10%), 178 (16%), and 276 (16%), respectively, died. In a comparison group of lifetime never-smokers, 178 (6%) died. After adjustment for daily cigarette dose, duration of smoking, age, gender, social class, type A personality, body mass index, urinary potassium, and antioxidant vitamin consumption, hazard ratios (95% confidence intervals) for all-cause mortality comparing low-tar smokers to low/middle-tar smokers and to middle- or high-tar smokers were 1.64 (1.04-2.58) and 1.46 (0.95-2.26), respectively. Corresponding results for cardiovascular disease were 1.48 (0.74-2.96) and 1.35 (0.79-2.60). For lung cancer, after adjusting for known confounding factors, corresponding hazard ratios were 2.82 (0.98-8.15) and 2.30 (0.81-6.49). CONCLUSIONS: Smoking any type of cigarette is far more risky than abstaining altogether. Although the results obtained comparing tar levels are limited because of lack of repeat measures of smoking during follow-up, potential residual confounding factors, statistical imprecision, and failure to show a dose-response relationship, results do support the hypothesis that persistent smokers will reduce their tobacco-induced health risk if they smoke cigarettes with < 10 mg of tar. However, the data do not permit quantification of the benefits of switching to lower-tar cigarettes. Worldwide legislation to limit tar levels to 10 mg as an absolute maximum is recommended, while recognizing that this must be part of an integrated approach to tobacco control.

Adult↗
PubMed2000

Effect of parity on milk yield, composition, somatic cell count, renneting parameters and bacteria counts of Comisana ewes.

Twenty-four Comisana ewes, with no history of mastitis, were included in this study, with eight ewes each in parities 1, 2 and 3. Groups were separately penned on straw litter and ewes were individually checked for yield, composition, renneting properties and bacteriological characteristics of milk from January, when separated from their lambs (50+/-3 days after lambing), to May. Samples with more than 3.5x10(5) somatic cells/ml were cultured for mastitis related pathogens. Milk yield was not significantly affected by parity. The P3 ewes had significantly higher milk protein, casein and fat contents compared to the P1 and P2 ewes. The P3 ewes also had improved renneting ability of milk as compared to the P1 ewes. Quality of milk decreased with lower lactations. The milk of P1 ewes had significantly greater amounts of mesophilic bacteria than the P2 and P3 ewes, as well as higher concentrations of psychrotrophs and total coliforms in their milk with respect to the P3 ewes. Somatic cell counts in milk and the prevalence of subclinical mastitis were not changed by parity, although mastitis infection set in progressively earlier as the number of lactations decreased. These results suggest that ewes in first or second lactation have a less favourable milk secretion status in relation to mastitis than ewes with a higher number of lactations. Milk yield and quality of younger ewes may be improved by offering feed rations that take into account this reduced capacity to mobilise body reserves. Also, most scrupulous control of sanitation of housing, equipment and personnel is necessary.

Journal Article↗
PubMed2002

Relative efficacy of different distillery effluents on growth, nitrogen fixation and yield of groundnut.

A field experiment with groundnut as test crop was conducted to evaluate the manurial potential of three distillery effluents: raw spent wash (RSW), biomethanated spent wash (BSW) and lagoon sludge (LS) vis-à-vis recommended fertilizers (NPK + farm yard manure (FYM)) and a control (no fertilizer or distillery effluent). It was found that all the three distillery effluents increased total chlorophyll content, crop growth rate (CGR), total dry matter, nutrient uptake (N, P and K) and finally seed yield compared to the control but inhibited nodulation and decreased nitrogen fixation. Among the three distillery effluents, BSW produced the highest seed yield (619 kg ha(-1)) twice that of control (3.10 kg ha(-1)), followed by RSW (557 kg ha(-1)) and LS (472 kg ha(-1)). However, the distillery effluents did not influence protein and oil contents. It was concluded that these distillery effluents because of their high manurial potential could supply nutrients, particularly potassium, nitrogen and sulphur, to the crops and thus reduce the fertilizer requirement of crops. Nevertheless, the crop performance and yield with three distillery effluents were overall less than that produced by recommended NPK + FYM probably on account of failure of the effluents to supply balanced nutrition to the plants for achieving their potential growth capacity.

Fertilizers↗
PubMed2003

Medicinal and aromatic plant materials as nitrification inhibitors for augmenting yield and nitrogen uptake of Japanese mint (Mentha arvensis L. Var. Piperascens).

Pot experiments were conducted to evaluate the relative performance of medicinal and aromatic plant materials and dicyandiamide (DCD) as nitrification inhibitors to regulate transformation of N from urea. Their effect on the efficiencies of use of N by Japanese mint (Mentha arvensis cv. Hy 77) was tested. Urea was coated with these materials viz., Mentha spicata, Artemisia annua or DCD at the rate of 5% (w/w) of fertilizer urea using an appropriate coating technique. Nimin (tetranortriterpenoids, an ethanol extract of neem (Azadirachta indica Juss) coating was done at the rate of 1% w/w of urea. Fertilizer nitrogen was applied at 100 and 200 mg kg(-1) soil. These natural coating materials significantly increased the herb and essential oil yields of the crop at both rates of fertilizer nitrogen compared to urea alone and were found to be as effective as DCD in retarding NO3- formation in soil. Herb yield increased by 6-81% when compared to uncoated urea. The increase in essential oil yield ranged between 3% and 68% due to coating. The effectiveness of the nitrification-inhibitor--coated urea, however, varied with the soils used and the rate of fertilizer nitrogen applied. The results suggest that the natural products could be potential nitrification inhibitors for increasing fertilizer N use efficiency.

Biological Availability↗
PubMed2003

Yield of Cassia angustifolia in combination with different tree species in a silvi-herbal trial under hot arid conditions in India.

A silvi-herbal trial was conducted in the hot arid region of India to study the performance of a shrub (Cassia angustifolia) in combination with different tree species. The study area was frequented by frost. Leaf yield of C. angustifolia under different treatments was estimated. It was found that the shrubs produced a significantly higher yield of leaves in the vicinity of the tree species as compared to the shrubs at a far distance from the trees. This was perhaps because of more protection of crops near the canopy of the plants during frosts. The yield was not much affected by the variation of tree species indicating that the effect of tree-shrub combination was not profound. C. angustifolia as inter-crop provides support to the farming system by way of conferring stability and generating assured income.

Desert Climate↗
PubMed2003

Influence of an organic mulching on fertilizer nitrogen use efficiency and herb and essential oil yields in geranium (Pelargonium graveolens).

In a field study, conducted at Lucknow ( 26.5 degrees N, 80.5 degrees E and 120 m altitude), India for two years (1996-1997 and 1997-1998), eight treatment combinations of two variables of organic mulch (paddy straw at 7 t/ha and no mulch) and four levels of fertilizer nitrogen (0, 80, 160 and 240 kg/ha) were examined to observe the effect of organic mulching on N-use efficiency and essential oil yield in a multi-harvested geranium crop. Results revealed that application of paddy straw mulch increased the herb and essential oil yields in geranium by 23% and 27%, respectively, over the unmulched control at planted crop harvest. Corresponding values at regenerated crop harvest were 18.7% and 19.2%. A significant response to N was observed with 160 kgN/ha in mulched plot over the same level of N in the unmulched plot. Using paddy straw mulch, nitrogen uptake by plants of planted and regenerated crops was increased by 33% and 28.4%, respectively, over the unmulched control. Apparent N recoveries by planted and regenerated crops were estimated to be 33.7% and 22.7% for the unmulched control, as against 40% and 29.2% with paddy straw mulch at 160 kgN/ha. The quality of essential oil of geranium in terms of its major constituents, citronellol and geraniol, was not affected by the use of organic mulching and nitrogen fertilization and these constituents were found to be of a standard acceptable in international trade. It was concluded from this study that use of an organic mulch with 160 kgN/ha proved better in terms of economising 80 kgN/ha to produce an economic yield of 96.1 kg geranium oil from two harvests under subtropical conditions of the north Indian plains. At 160 kgN/ha, paddy straw mulch application permitted the geranium crop to produce 18.4 kg/ha more oil which gave an additional return of Rs. 53,600/ha than that of unmulched control. Paddy straw mulch and nitrogen fertilization had no adverse effect on the quality of essential oil of geranium.

Agriculture↗
PubMed2004

Effect of different organic manures/composts on the herbage and essential oil yield of Cymbopogon winterianus and their influence on the native AM population in a marginal alfisol.

Four organic amendments: leaf compost (LC), vegetable compost (VC), poultry manure (PM) and sewage sludge (SSL) applied at four doses (40, 80, 100 and 120 tha(-1)) were evaluated for their effect on the herbage yield, essential oil content and inoculum potential (IP) of native arbuscular mycorrhizal fungi (AMF) on three varieties of Java citronella, Cymbopogon winterianus Jowitt (Manjusha, Mandakini, and Bio-13). PM applied at 100 t ha(-1) followed by SSL increased the herbage, essential oil content and dry matter yield significantly. Bio-13 performed better and produced the highest herbage, essential oil and dry matter yield. The type and dose of the various organic amendments also significantly influenced the indigenous AMF infectious propagules in soil. Highest number of AMF propagules were recorded in the LC amended plots in all the three varieties. Amongst the varieties, highest native mycorrhizal inoculum was recorded in the Bio-13. Least number of AM infectious propagules were recorded in the Mandakini plants grown in 40 t ha(-1) SSL.

Biomass↗
PubMed2002

Measurement of L3 subshell fluorescence yields of some elements in the atomic range 57 < or = Z < or = 68 using photoionisation.

L3 X-ray production cross sections have been measured for the elements in the atomic range 57< or = Z < or = 68 at 59.5 keV. The values of L3 subshell fluorescence yields (omega3) have been measured for the same elements using the presently measured cross section values and the theoretical Li subshell photoionisation cross sections, Coster-Kronig transition probabilities, emission rates and vacancy transfer probabilities. The measured X-ray production cross section values are in general agreement with the theoretical values evaluated using L3 subshell fluorescence yields, Coster-Kronig transition probabilities, emission rates, vacancy transfer probabilities and subshell photoionisation cross sections. Furthermore, the values of L3 subshell fluorescence yields are in good agreement with the theoretical values.

Journal Article↗
PubMed2002

Thin-target excitation functions, cross-sections and optimised thick-target yields for natMo(p,xn)(94g ,95m,95g,96(m + g))Tc nuclear reactions induced by protons from threshold up to 44 MeV. No Carrier Added radiochemical separation and quality control.

This work describes the method adopted in our laboratories, to produce 94gTc, 95gTc, 95mTc and 96gTc radionuclides via proton-cyclotron irradiation on molybdenum targets of natural isotopic composition. A new set of experimental thin-target excitation functions and "effective" cross-sections for direct natMo(p,xn)(A)Tc [with A = 94, 95, 95, 96] nuclear reactions, with incident proton energy in the range from threshold up to 44 MeV is presented. Some definitions of the equations used and nuclear data traceability are reported. Thick-target yield values were calculated and optimised, by numerical fitting and integration of the measured excitation functions. These values allow optimisation of production yield of one radionuclide, minimising at the same time the yield of the others. Radiochemical separation on NCA technetium radionuclides from both molybdenum target and niobium, zirconium and yttrium radioactive by-products is reported. Quality control tests of the radiotracers were developed for the applications envisaged in environmental metallo-biochemical toxicology.

Journal Article↗
PubMed2002

Low-temperature, high yield synthesis, and convenient isolation of the high-electron-density cluster compound Ta6Br14.8H2O for use in biomacromolecular crystallographic phase determination.

Reduction of TaBr(5) with Ga in the presence of KBr in a sealed borosilicate ampule at 400 degrees, followed by aqueous Soxhlet extraction and addition of stannous bromide and hydrobromic acid to the extract, yielded Ta(6)Br(14).8H(2)O in 80-84% yield. The new procedure provides a convenient, low temperature, high yield route to the synthesis of the title compound from inexpensive precursors.

Crystallography, X-Ray↗