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1.
Precise and accurate patient positioning is necessary when doing stereotactic radiosurgery (SRS) to ensure adequate dosing to the tumor and sparing of normal tissues. This prospective cross‐sectional study aimed to assess feasibility of a commercially available modified frameless SRS positioning system for use in veterinary radiotherapy patients with brain tumors. Fifty‐one dogs and 12 cats were enrolled. Baseline and verification CT images were acquired. The verification CT images from 32 dogs and five cats had sufficient images for fusion to baseline CT images. A rigid box‐based fusion was performed to determine interfraction motion. Forty‐eight dogs and 11 cats were assessed for intrafraction motion by cine CT. Seventy percent of dogs and 60% of cats had interfraction 3D vector translational shifts >1 mm, with mean values of 1.9 mm in dogs, and 1.8 mm in cats. In dogs muscle wasting was weakly correlated with translational shifts. The maximum angular interfraction motion observed was 6.3° (roll), 3.5° (pitch), and 3.3° (yaw). There was no correlation between angular interfraction motion and weight, brachycephaly, or muscle wasting. Fifty‐seven percent of dogs and 50% of cats had respiration‐related intrafraction motion. Of these, 4.5% of dogs and 10% of cats had intrafraction motion >1 mm. This study demonstrates the modified Brainlab system is feasible for SRS in dogs and cats. The smaller cranial size and difference in anatomy increases setup uncertainty in some animals beyond limits usually accepted in SRS. Image‐guided positioning is recommended to achieve clinically acceptable setup accuracy (<1 mm) for SRS.  相似文献   
2.
We assessed the influence of stand age on fine root biomass and morphology of trees and understory vegetation in 10-, 30-, 60- and 120-year-old Norway spruce stands growing in sandy soil in southeast Norway. Fine root (< 1, 1-2 and 2-5 mm in diameter) biomass of trees and understory vegetation (< 2 mm in diameter) was sampled by soil coring to a depth of 60 cm. Fine root morphological characteristics, such as specific root length (SRL), root length density (RLD), root surface area (RSA), root tip number and branching frequency (per unit root length or mass), were determined based on digitized root data. Fine root biomass and morphological characteristics related to biomass (RLD and RSA) followed the same tendency with chronosequence and were significantly higher in the 30-year-old stand and lower in the 10-year-old stand than in the other stands. Among stands, mean fine root (< 2 mm) biomass ranged from 49 to 398 g m(-2), SLR from 13.4 to 19.8 m g(-1), RLD from 980 to 11,650 m m(-3) and RSA from 2.4 to 35.4 m(2) m(-3). Most fine root biomass of trees was concentrated in the upper 20 cm of the mineral soil and in the humus layer (0-5 cm) in all stands. Understory fine roots accounted for 67 and 25% of total fine root biomass in the 10- and 120-year-old stands, respectively. Stand age had no affect on root tip number or branching frequency, but both parameters changed with soil depth, with increasing number of root tips and decreasing branching frequency with increasing soil depth for root fractions < 2 mm in diameter. Specific (mass based) root tip number and branching density were highest for the finest roots (< 1 mm) in the humus layer. Season (spring or fall) had no effect on tree fine root biomass, but there was a small and significant increase in understory fine root biomass in fall relative to spring. All morphological characteristics showed strong seasonal variation, especially the finest root fraction, with consistently and significantly higher values in spring than in fall. We conclude that fine root biomass, especially in the finest fraction (< 1 mm in diameter), is strongly dependent on stand age. Among stands, carbon concentration in fine root biomass was highest in the 30-year-old stand, and appeared to be associated with the high tree and canopy density during the early stage of stand development. Values of RLD and RSA, morphological features indicative of stand nutrient-uptake efficiency, were higher in the 30-year-old stand than in the other stands.  相似文献   
3.
Conifers and other trees are constantly adapting to changes in light conditions, water/nutrient supply and temperatures by physiological and morphological modifications of their foliage. However, the relationship between physiological processes and anatomical characteristics of foliage has been little explored in trees. In this study we evaluated needle structure and function in Norway spruce families exposed to different light conditions and transpiration regimes. We compared needle characteristics of sun-exposed and shaded current-year needles in a control plot and a thinned plot with 50% reduction in stand density. Whole-tree transpiration rates remained similar across plots, but increased transpiration of lower branches after thinning implies that sun-exposed needles in the thinned plot were subjected to higher water stress than sun-exposed needles in the control plot. In general, morphological and anatomical needle parameters increased with increasing tree height and light intensity. Needle width, needle cross-section area, needle stele area and needle flatness (the ratio of needle thickness to needle width) differed most between the upper and lower canopy. The parameters that were most sensitive to the altered needle water status of the upper canopy after thinning were needle thickness, needle flatness and percentage of stele area in needle area. These results show that studies comparing needle structure or function between tree species should consider not only tree height and light gradients, but also needle water status. Unaccounted for differences in needle water status may have contributed to the variable relationship between needle structure and irradiance that has been observed among conifers.  相似文献   
4.
A simple and fast reversed-phase HPLC method using diode array detection was developed and validated for the simultaneous determination of trans-resveratrol and quercetin in Sicilian red wine from the Nero d'Avola red grape variety. Investigation was also extended to the quantitative determination of resveratrol and quercetin in grape skins and winemaking byproducts obtained from the same cultivar. Samples were eluted using a C18 narrow-bore column under isocratic conditions in less than 20 min. Quantification of trans-resveratrol and quercetin in red wine was performed without any sample pretreatment, whereas the determination of these phenolic compounds in grape skins and wine pomage required a solvent extraction procedure. Linearity was demonstrated over the 0.39-12.5 and 0.45-57.6 microg/mL range for trans-resveratrol and quercetin, respectively. Detection limits in real samples were in the low ppm level (0.07 mg/L for trans-resveratrol and 0.12 mg/L for quercetin). The HPLC-UV/DAD method was applied for the routine analyses of red wine and grape skin and winemaking byproduct extracts to evaluate their trans-resveratrol and quercetin content. In particular, a very high content of quercetin was found in wine pomace, suggesting the use of this wine byproduct as a potential source of this health-promoting phenolic compound.  相似文献   
5.
6.
The isolation of broadly neutralizing antibodies against influenza A viruses has been a long-sought goal for therapeutic approaches and vaccine design. Using a single-cell culture method for screening large numbers of human plasma cells, we isolated a neutralizing monoclonal antibody that recognized the hemagglutinin (HA) glycoprotein of all 16 subtypes and neutralized both group 1 and group 2 influenza A viruses. Passive transfer of this antibody conferred protection to mice and ferrets. Complexes with HAs from the group 1 H1 and the group 2 H3 subtypes analyzed by x-ray crystallography showed that the antibody bound to a conserved epitope in the F subdomain. This antibody may be used for passive protection and to inform vaccine design because of its broad specificity and neutralization potency.  相似文献   
7.
Protein aggregation is involved in the pathogenesis of neurodegenerative diseases and hence is considered an attractive target for therapeutic intervention. However, protein-protein interactions are exceedingly difficult to inhibit. Small molecules lack sufficient steric bulk to prevent interactions between large peptide surfaces. To yield potent inhibitors of beta-amyloid (Abeta) aggregation, we synthesized small molecules that increase their steric bulk by binding to chaperones but also have a moiety available for interaction with Abeta. This strategy yields potent inhibitors of Abeta aggregation and could lead to therapeutics for Alzheimer's disease and other forms of neurodegeneration.  相似文献   
8.
Summary Potatoes of cv. Désirée and Pentland Crown, treated in February at 0, 0.6, 1.2, 2.5, 5, 10, and 20 mg kg1 chlorpropham adsorbed on alumina, were sampled for analysis immediately before planting at the beginning of May. Chlorpropham was extracted using hexane as the solvent in the presence of anhydrous sodium sulphate. Emergence and yield data showed that low levels of chlorpropham (<0.3 mg kg−1) that had little effect on total emergence, increased the mean emergence time and reduced yield. High levels of chlorpropham drastically reduced total emergence and yield.
Zusammenfassung Chlorpropham (Isopropyl-N-(3-chlorophenyl) carbamat) ist ein weitverbreitetes Keimhemmungsmittel, das niemals bei Pflanzkartoffeln angewendet wird, da es ein die Zellteilung hemmendes Gift ist. Zuf?llige Kontamination kann jedoch erfolgen und es war daher der Sinn dieses Versuches, die Mengen an Chlorpropham zu bestimmen, die nachweislich den Auflauf, den Ertrag und die Gr?ssenverteilung der nachfolgenden Ernte beeinflussen. Zwei Proben von je 7,5 kg der Sorten Désirée und Pentland Crown wurden mit Chlorpropham in den Aufwandmengen von 0, 0,6, 1, 2, 2,5, 5, 10 und 20 mg/kg best?ubt. Nach der Lagerung bei 10°C in fest verschliessbaren Beh?ltern wurden sie zwei Wochen vor dem pflanzdatum vorgekeimt und 1 kg für die Rückstandsanalysen abgenommen. Der Rest wurde gepflanzt und Auflauf und Ertrag bestimmt. Die Extraktion von Chlorpropham erfolgte nach der Methode von Cerny & Blumenthal (1972) und es wurde eine neue Reinigungsmethode entwickelt, die den Einsatz eines Gaschromatographen mit einem Flammenionisationsdetektor erlaubt. Tabelle 1 zeigt die Rückstandswerte und die entsprechenden Angaben für den Feldbestand. Der Einfluss von Chlorpropham war bei der Sorte Pentland Crown deutlicher, aber allgemein verl?ngerten sehr kleine Rückstandswerte (<0.3 mg/kg) bereits die durchschnittliche Auflaufzeit und verringerten leicht den Ertrag, obwohl die gesamte Auflaufrate nahe bei 100% blieb. H?here Werte (0,3–1 mg/kg) verz?gerten den Auflauf und reduzierten den Ertrag. Rückst?nde über 1 mg/kg führten zu geringem Auflauf und einer drastischen Ertragseinbusse. Lagerh?user in denen Chlorpropham angewendet wird oder in denen behandelte Knollen gelagert werden sind offensichtlich Quellen der Kontamination mit geringen Mengen.

Résumé Le chlorprophame (isoprophyl-N-(3 chlorophenyl) carbamate) est un inhibiteur de germination très employé mais jamais sur pomme de terre de semence parce que c'est un poison mitotique. Une contamination accidentelle peut avoir lieu et l'objet de cette expérimentation était de déterminer les taux de chlorprophame qui affectent de fa?on significative la germination, le rendement et la distribution par calibre de la culture suivante. Une expérimentation à 2 répétitions a été faite avec du chlorprophame par poudrage à différentes concentrations: 0, 0,6, 1,2, 2,5, 5, 10, et 20 mg/kg sur des échantillons de 7,5 kg pour les variétés Désirée et Pentland Crown. Ces échantillons ont été conservés à 10°C dans des bo?tes fermées hermétiquement et prégermés pendant 2 semaines avant la date de plantation tandis qu'un échantillon de 1 kg a été prélevé pour une analyse de résidus. Les tubercules restants ont été plantés et les notations de levée et de rendement ont été effectuées. La méthode de Cerny & Blumenthal (1972) a été employée pour extraire le chlorprophame et une nouvelle technique de lavage a été imaginé afin d'obtenir des échantillons adaptés á la chromatographie en phase gazeuse utilisant la détection thermoionique. Les teneurs en résidus et les notations au champ correspondantes sont indiquées dans le tableau 1. L'effet du chlorprophame était plus accentué pour les variétés Pentland Crown mais, en général, de faibles taux en résidus (<0,3 mg/kg) retardaient la durée de levée moyenne et réduisaient légèrement les rendements quoique la levée totale approchait 100%. Les taux de résidus plus élevés (0,3 → 1,0 mg/kg) retardaient également la levée et diminuaient les rendements. Les résidus supérieurs à 1,0 mg/kg provoquaient une mauvaise levée et des réductions sérieuses de rendement. Les locaux utilisés pour l'application du chlorprophame ou pour la conservation de tubercules traités sont indiscutablement des sources faibles de contamination.
  相似文献   
9.
Cannabis sativa L. is an annual herbaceous plant. It was used for centuries to obtain different products. In the last century, hemp cultivation was forbidden due to the psychoactive effects of tetrahydrocannabinol acid (THCA). In the last years, new strains, characterized by high cannabidiolic acid (CBDA) and low THCA level, were developed renewing the interest in hemp cultivation to obtain food or to extract essential oils from flowers. All these processes produce many residues with different chemical–physical characteristics. In order to evaluate their potential use also in animal nutrition, some hemp co-products were evaluated. Two different co-products of seed processes (flour and oil) and two co-products obtained trimming the flowers, differing in granulometry were used. The samples were analysed for chemical composition and evaluated in vitro using the gas production technique with buffaloes' ruminal inoculum. All hemp co-products showed interesting nutritional characteristics, such as crude protein content always higher than 20% on a dry matter basis, and high neutral detergent fibre concentration partially lignified. The in vitro gas production parameters at 120 h of incubation showed quite low fermentability testified by the low organic matter degradability and cumulative gas volume (OMD from 28.09 to 45.64% and OMCV from 110 to 164 ml/g, respectively). Also, the methane produced after 24 h of incubation was particularly low (from 1.78 to 11.73 ml/g dOM). These results could be due to the high lipid and ash amounts or to the CBDA content that probably affected the CH4 formation processes. According to preliminary results obtained by this study, it is possible to hypothesize that these co-products could be useful to mitigate the methane production into the rumen. Further studies are necessary in order to evaluate the correct inclusion into the diet for ruminants.  相似文献   
10.
The Paleocene-Eocene Thermal Maximum (PETM) has been attributed to a rapid rise in greenhouse gas levels. If so, warming should have occurred at all latitudes, although amplified toward the poles. Existing records reveal an increase in high-latitude sea surface temperatures (SSTs) (8 degrees to 10 degrees C) and in bottom water temperatures (4 degrees to 5 degrees C). To date, however, the character of the tropical SST response during this event remains unconstrained. Here we address this deficiency by using paired oxygen isotope and minor element (magnesium/calcium) ratios of planktonic foraminifera from a tropical Pacific core to estimate changes in SST. Using mixed-layer foraminifera, we found that the combined proxies imply a 4 degrees to 5 degrees C rise in Pacific SST during the PETM. These results would necessitate a rise in atmospheric pCO2 to levels three to four times as high as those estimated for the late Paleocene.  相似文献   
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