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11.
Diagnosis of infantile and juvenile forms of GM2 gangliosidosis variant 0. residual activities toward natural and different synthetic substrates 总被引:1,自引:0,他引:1
Summary p-Nitrophenyl-6-sulfo-2-acetamido-2-deoxy--d-glucopyranoside, which is known to be a specific substrate for human hexosaminidase A, has recently been used successfully for diagnosis of variants B and B1 of GM2-gangliosidosis (Fuchs et al. 1983; Kytzia et al. 1983; Li et al. 1983). However, it is hydrolyzed by hexosaminidase S as well and is therefore not suitable for detection of patients with variant 0, who reach the normal range of activity toward this substrats. Assay of ganglioside GM2 cleaving activity in fibroblast extracts in the presence of the natural GM2 activator protein reveals residual hexosaminidase A activities of less than 2% of normal controls in two infantile and up to 7.5% in two juvenile patients with variant 0. 相似文献
12.
Spontaneous activity was recorded extracellularly by glass microelectrodes from 54 neurons of the Gyrus sigmoideus posterior of unnarcotized and gallamine-immobilazed cats, and the sequential and nonsequential interspike-interval histograms were determined using the multi-channel analyzer CAT 400 C. The interval distributions were characterized by graphic criteria, and it was attempted to describe these distributions mathematically by four biparametric distributions, the Weibull, lognormal, gamma and normal distributions. 80% of the frequency distributions of type I (exponential), II (left skew, gamma-similar) and IV (almost symmetrical) could be assigned to these distributions, namely 43% of the lognormal distribution, 32% of the Weibull distribution, and 5% of the gamma distribution. The interval histograms of the type III (left skew, steep) and V (bimodal) could not be described by any of the distributions selected. 相似文献
13.
A. S. Bradley H. F. Fredricks K.‐U. Hinrichs E. L. Shock R. E. Summons 《Geobiology》2013,11(6):549-569
Detailed analysis of 16S rRNA and intact polar lipids (IPLs) from streamer biofilm communities (SBCs), collected from geochemically similar hot springs in the Lower Geyser Basin, Yellowstone National Park, shows good agreement and affirm that IPLs can be used as reliable markers for the microbial constituents of SBCs. Uncultured Crenarchaea are prominent in SBS, and their IPLs contain both glycosidic and mixed glyco‐phospho head groups with tetraether cores, having 0–4 rings. Archaeal IPL contributions increase with increasing temperature and comprise up to one‐fourth of the total IPL inventory at >84 °C. At elevated temperatures, bacterial IPLs contain abundant glycosidic glycerol diether lipids. Diether and diacylglycerol (DAG) lipids with aminopentanetetrol and phosphatidylinositol head groups were identified as lipids diagnostic of Aquificales, while DAG glycolipids and glyco‐phospholipids containing N‐acetylgycosamine as head group were assigned to members of the Thermales. With decreasing temperature and concomitant changes in water chemistry, IPLs typical of phototrophic bacteria, such as mono‐, diglycosyl, and sulfoquinovosyl DAG, which are specific for cyanobacteria, increase in abundance, consistent with genomic data from the same samples. Compound‐specific stable carbon isotope analysis of IPL breakdown products reveals a large isotopic diversity among SBCs in different hot springs. At two of the hot springs, ‘Bison Pool’ and Flat Cone, lipids derived from Aquificales are enriched in 13C relative to biomass and approach values close to dissolved inorganic carbon (DIC) (approximately 0‰), consistent with fractionation during autotrophic carbon fixation via the reversed tricarboxylic acid pathway. At a third site, Octopus Spring, the same Aquificales‐diagnostic lipids are 10‰ depleted relative to biomass and resemble stable carbon isotope values of dissolved organic carbon (DOC), indicative of heterotrophy. Other bacterial and archaeal lipids show a similar variance, with values resembling the DIC or DOC pool or a mixture thereof. This variance cannot be explained by hot spring chemistry or temperature alone, but instead, we argue that intermittent input of exogenous organic carbon can result in metabolic shifts of the chemotrophic communities from autotrophy to heterotrophy and vice versa. 相似文献
14.
Emma J. Gagen Harald Huber Travis Meador Kai-Uwe Hinrichs Michael Thomm 《Applied and environmental microbiology》2013,79(20):6400-6406
The uncultured miscellaneous crenarchaeotic group (MCG) archaea comprise one of the most abundant microbial groups in the Earth''s subsurface environment. However, very little information is available regarding the lifestyle, physiology, and factors controlling the distribution of members of this group. We established a novel method using both cultivation and molecular techniques, including a pre-PCR propidium monoazide treatment, to investigate viable members of the MCG in vitro. Enrichment cultures prepared from estuarine sediment were provided with one of a variety of carbon substrates or cultivation conditions and incubated for 3 weeks. Compared with the samples from time zero, there was an order-of-magnitude increase in the number of MCG 16S rRNA genes in almost all cultures, indicating that MCG archaea are amenable to in vitro cultivation. None of the tested substrates or conditions significantly stimulated growth of MCG archaea more than the basal medium alone; however, glycerol (0.02%) had a significantly inhibitory effect (P < 0.05). Diversity analysis of populations resulting from four culture treatments (basal medium, addition of amino acids, H2-CO2 as the gas phase, or initial aerobic conditions) revealed that the majority of viable MCG archaea were affiliated with the MCG-8 and MCG-4 clusters. There were no significant differences in MCG diversity between these treatments, also indicating that some members of MCG-4 and MCG-8 are tolerant of initially oxic conditions. The methods outlined here will be useful for further investigation of MCG archaea and comparison of substrates and cultivation conditions that influence their growth in vitro. 相似文献
15.
Nicole Sommer Tina Junne Kai-Uwe Kalies Martin Spiess Enno Hartmann 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》2013,1833(12):3104-3111
Membrane protein insertion and topogenesis generally occur at the Sec61 translocon in the endoplasmic reticulum membrane. During this process, membrane spanning segments may adopt two distinct orientations with either their N- or C-terminus translocated into the ER lumen. While different topogenic determinants in membrane proteins, such as flanking charges, polypeptide folding, and hydrophobicity, have been identified, it is not well understood how the translocon and/or associated components decode them. Here we present evidence that the translocon-associated protein (TRAP) complex is involved in membrane protein topogenesis in vivo. Small interfering RNA (siRNA)-mediated silencing of the TRAP complex in HeLa cells enhanced the topology effect of mutating the flanking charges of a signal-anchor, but not of increasing signal hydrophobicity. The results suggest a role of the TRAP complex in moderating the ‘positive-inside’ rule. 相似文献
16.
Oliver G. Bosch Michael Wagner Frank Jessen Kai-Uwe Kühn Alexius Joe Erich Seifritz Wolfgang Maier Hans-Jürgen Biersack Boris B. Quednow 《PloS one》2013,8(4)
Introduction
3,4-Methylenedioxymethamphetamine (MDMA, “ecstasy”) is a recreational club drug with supposed neurotoxic effects selectively on the serotonin system. MDMA users consistently exhibit memory dysfunction but there is an ongoing debate if these deficits are induced mainly by alterations in the prefrontal or mediotemporal cortex, especially the hippocampus. Thus, we investigated the relation of verbal memory deficits with alterations of regional cerebral brain glucose metabolism (rMRGlu) in recreational MDMA users.Methods
Brain glucose metabolism in rest was assessed using 2-deoxy-2-(18F)fluoro-D-glucose positron emission tomography (18FDG PET) in 19 male recreational users of MDMA and 19 male drug-naïve controls. 18FDG PET data were correlated with memory performance assessed with a German version of the Rey Auditory Verbal Learning Test.Results
As previously shown, MDMA users showed significant impairment in verbal declarative memory performance. PET scans revealed significantly decreased rMRGlu in the bilateral dorsolateral prefrontal and inferior parietal cortex, bilateral thalamus, right hippocampus, right precuneus, right cerebellum, and pons (at the level of raphe nuclei) of MDMA users. Among MDMA users, learning and recall were positively correlated with rMRGlu predominantly in bilateral frontal and parietal brain regions, while recognition was additionally related to rMRGlu in the right mediotemporal and bihemispheric lateral temporal cortex. Moreover, cumulative lifetime dose of MDMA was negatively correlated with rMRGlu in the left dorsolateral and bilateral orbital and medial PFC, left inferior parietal and right lateral temporal cortex.Conclusions
Verbal learning and recall deficits of recreational MDMA users are correlated with glucose hypometabolism in prefrontal and parietal cortex, while word recognition was additionally correlated with mediotemporal hypometabolism. We conclude that memory deficits of MDMA users arise from combined fronto-parieto-mediotemporal dysfunction. 相似文献17.
Acoustic sensing and signal processing techniques for monitoring milk fouling cleaning operations
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Marco A. Úbeda Walid B. Hussein Mohamed A. Hussein Jörg Hinrichs Thomas M. Becker 《Engineering in Life Science》2016,16(1):67-77
Large resource investments are necessary in order to minimize the limiting problems arising from food industrial intensive productivity. One of the most challenging concerns is the cleaning status uncertainty among heat transfer areas in dairy heat exchangers, since the effectiveness of this process cannot be easily validated. The present study aimed to develop a low‐power ultrasound sensing method for monitoring the removal of milk fouling deposits along cleaning processes inside an experimental plate heat exchanger structure, connected to a milk piping unit. For that purpose, signal processing, namely acoustic feature extraction, over different wave patterns combined with artificial neural network techniques was used. Measurements were taken in pulse‐echo mode with a handmade 4 MHz ultrasound transducer. While fouling deposits having initial average thickness values of 250 μm (34.5 ± 4.5 mg/cm²) were removed, the acoustic transmissivity increased. Results showed that the signal features follow the expected trends in both, clean and fouled cases, within right guess detection accuracies above 80%. Therefore, when calibrated well, this could be a very sensitive and noninvasive technique for material characterization, as well as a suitable validation method for industrial cleaning cycle operation optimization that could significantly reduce the associated costs. 相似文献
18.
19.
Wendy W. J. de Leng Christa G. Gadellaa-van Hooijdonk Fran?oise A. S. Barendregt-Smouter Marco J. Koudijs Ies Nijman John W. J. Hinrichs Edwin Cuppen Stef van Lieshout Robert D. Loberg Maja de Jonge Emile E. Voest Roel A. de Weger Neeltje Steeghs Marlies H. G. Langenberg Stefan Sleijfer Stefan M. Willems Martijn P. Lolkema 《PloS one》2016,11(2)