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31.
32.
Behavioral flexibility, including an ability to modify feeding behavior, is a key trait enabling primates to survive in forest fragments. In human-dominated landscapes, unprotected forest fragments can become progressively degraded, and may be cleared entirely, challenging the capacity of primates to adjust to the changes. We examined responses of wild chimpanzees (Pan troglodytes schweinfurthii) to major habitat change: that is, clearance of forest fragments for agriculture. Over 7 years, fragments in Bulindi, Uganda, were reduced in size by 80%. We compared the chimpanzees’ diet at the start and end of this period of rapid deforestation, using data derived mainly from fecal analysis. Similar to other long-term study populations, chimpanzees in Bulindi have a diverse diet comprising over 169 plant foods. However, extensive deforestation seemed to impact their feeding ecology. Dietary changes after fragment clearance included reduced overall frugivory, reduced intake of figs (Ficus spp.; formerly a dietary “staple” for these chimpanzees), and reduced variety of fruits in fecal samples. Nevertheless, the magnitude of most changes was remarkably minor given the extent of forest loss. Agricultural fruits increased in dietary importance, with crops accounting for a greater proportion of fruits in fecal samples after deforestation. In particular, cultivated jackfruit (Artocarpus heterophyllus) became a “staple” food for the chimpanzees but was scarcely eaten before fragment clearance. Crops offer some nutritional benefits for primates, being high in carbohydrate energy and low in hard-to-digest fiber. Thus, crop feeding may have offset foraging costs associated with loss of wild foods and reduced overall frugivory for the chimpanzees. The adaptability of many primates offers hope for their conservation in fragmented, rural landscapes. However, long-term data are needed to establish whether potential benefits (i.e. energetic, reproductive) of foraging in agricultural matrix habitats outweigh fitness costs from anthropogenic mortality risk for chimpanzees and other adaptable primates.  相似文献   
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People are an inescapable aspect of most environments inhabited by nonhuman primates today. Consequently, interest has grown in how primates adjust their behavior to live in anthropogenic habitats. However, our understanding of primate behavioral flexibility and the degree to which it will enable primates to survive alongside people in the long term remains limited. This Special Issue brings together a collection of papers that extend our knowledge of this subject. In this introduction, we first review the literature to identify past and present trends in research and then introduce the contributions to this Special Issue. Our literature review confirms that publications on primate behavior in anthropogenic habitats, including interactions with people, increased markedly since the 2000s. Publications concern a diversity of primates but include only 17% of currently recognized species, with certain primates overrepresented in studies, e.g., chimpanzees and macaques. Primates exhibit behavioral flexibility in anthropogenic habitats in various ways, most commonly documented as dietary adjustments, i.e., incorporation of human foods including agricultural crops and provisioned items, and as differences in activity, ranging, grouping patterns, and social organization, associated with changing anthropogenic factors. Publications are more likely to include information on negative rather than positive or neutral interactions between humans and primates. The contributions to this Special Issue include both empirical research and reviews that examine various aspects of the human–primate interface. Collectively, they show that primate behavior in shared landscapes does not always conflict with human interests, and demonstrate the value of examining behavior from a cost–benefit perspective without making prior assumptions concerning the nature of interactions. Careful interdisciplinary research has the potential to greatly improve our understanding of the complexities of human–primate interactions, and is crucial for identifying appropriate mechanisms to enable sustainable human–primate coexistence in the 21st century and beyond.  相似文献   
35.
The transforming growth factor betas (TGFβs) are context-dependent regulators of neurons in vitro, but their physiological functions in the brain are unclear. Haploinsufficiency of either Tgfβ1 or Tgfβ2 leads to age-related deterioration of neurons, but the development of the brain is normal in the full absence of either of these genes. However, some individuals with mis-sense mutations of TGFβ receptors are mentally retarded, suggesting that the TGFβ isoforms can compensate for each other during brain development. This possibility was tested by generating mice (NSE × PTR) with neuron-specific expression of a dominant-negative inhibitor of TGFβ signaling. The NSE × PTR mice with a FVBxC57Bl/6 genetic background were viable and developed normally despite strong neuronal expression of the inhibitor of TGFβ signaling. Their cerebella were of normal size and contained normal numbers of neurons. When the genetic background of the mice was changed to C57BL/6, the phenotype of the mice became neonatal lethal, with the neonates exhibiting various malformations. The malformations correlated with sites of non-neuronal expression of the transgenes and included facial dysmorphogenesis, incomplete closure of the ventral body wall and absence of intestinal motility. The C57BL/6 Tgfbm1–3 alleles, which modulate the phenotype of Tgfβ1−/− mice, were not major determinants of the NSE × PTR phenotype. The data suggest that the development of the cerebellum is insensitive to the level of TGFβ signaling, although this may be dependent on the genetic background.  相似文献   
36.
Four point-of-use disinfection technologies for treating sewage-contaminated well water were compared. Three systems, based on flocculant-disinfectant packets and N-halamine chlorine and bromine contact disinfectants, provided a range of 4.0 to >6.6 log10 reductions (LR) of naturally occurring fecal indicator and heterotrophic bacteria and a range of 0.9 to >1.9 LR of coliphage.Disasters and flooding can overwhelm sanitation infrastructure, leading to sewage contamination of potable waters. This may be routine during the wet season in many parts of the world and spreads numerous waterborne diseases (21). Point-of-use (POU) water treatment has reduced the incidence of diarrheal disease when used for household drinking water (3, 4, 6, 13) and is now being promoted for disaster relief. While POU systems have recently been reviewed (14), to our knowledge there has been no direct, experimental comparison for treating actual sewage-contaminated waters. In this study, the efficacies of four POU disinfection systems (based on sodium dichloroisocyanurate [NaDCC] tablets, a flocculent-disinfectant powder, and chlorine and bromine contact disinfectant cartridges) in reducing the concentrations of six microbial indicators in well water contaminated with raw sewage were compared.The NaDCC tablets (67 mg; Aquatabs; Medentech, Wexford, Ireland), used for disinfection in low-turbidity water, have shown preliminary efficacy for routine household drinking water treatment (3, 4). The flocculant-disinfectant packet (4 g; PUR; Procter & Gamble Co., Cincinnati, OH) includes Fe2(SO4)3, bentonite, Na2CO3, chitosan, polyacrylamide, KMnO4, and Ca(OCl)2 (13). It achieved >7.3 log10 reductions (LR) of 24 bacteria species; >4.6 LR of poliovirus and rotavirus in EPA no. 2 test water (turbidity, >30 nephelometric turbidity units [NTU]) (15); and reduced diarrheal illness in Guatemala, Liberia, Kenya, and Pakistan (6, 7, 11, 13).HaloPure canisters (Eureka Forbes, Mumbai, India) contain N-halamine polymer disinfectant beads, poly[1,2-dichloro-5-methyl-5-(4′-vinylphenyl)hydrantoin] for chlorine canisters, and poly[1,2-dibromo-5-methyl-5-(4′-vinylphenyl)hydrantoin] for bromine canisters. Seeded laboratory trials achieved >6.8 LR for Escherichia coli and Staphylococcus aureus as water was passed through the canisters (2). The Cl-contact (producing residuals ranging from 0 to 0.6 mg/liter) and Br-contact (with residuals of 0.68 to 1.8 mg/liter) disinfectants achieved 2.9 LR and 5.0 LR of the bacteriophage MS2, respectively, and 27.5% and 88.5% reductions of the algal toxin microcystin, respectively (5).Sewage-contaminated water was prepared by mixing 9 liters of potable, nonchlorinated well water (pH 7.8; turbidity, 0.33 NTU; Williamston, MI) with 1 liter of raw sewage (City of East Lansing Wastewater Treatment Plant, MI) with an average pH of 6.6 ± 0.1, a biochemical oxygen demand of 144 ± 36 mg/liter, a concentration of total suspended solids of 146 ± 31 mg/liter, and a turbidity of 132 ± 12 NTU. Three disinfection trials were conducted at room temperature for each POU system on three different days to allow for variance in sewage strength. The turbidities of 1:10 dilutions of raw sewage averaged 7.5 ± 2.0 NTU. Table Table11 lists the indicator microorganism concentrations in the influent and effluent for each system.

TABLE 1.

Concentrations of influent and 30-min-effluent microorganisms for POU disinfectant systems treating sewage-contaminated water
Microorganism groupGeometric mean concn (range) [% of samples below detection limit]a
NaDCC
Flocculant-disinfectant
Cl-contact
Br-contact
InfluentEffluent at 30 minInfluentEffluent at 30 minInfluentEffluent at 30 minInfluentEffluent at 30 min
Total coliforms2.7 × 104 (6.7 × 103 to 7.6 × 104)4.3 (4.0 × 10−2 to 1.6 × 102)1.7 × 104 (1.2 × 104 to 2.7 × 104)4.0 × 10−2 (<1.0 × 10−2 to 2.4 × 10−1) [33]2.9 × 104 (2.3 × 104 to 4.0 × 104)<1.0 × 10−2 [100]4.5 × 104 (1.9 × 104 to 7.2 × 104)1.1 × 10−2 (<1.0 × 10−2 to 1.3 × 10−2) [66]
Heterotrophic plate counts8.7 × 104 (2.7 × 104 to 1.8 × 105)6.4 × 101 (2.1 × 101 to 4.5 × 102)8.9 × 104 (2.9 × 104 to 4.3 × 105)8.5 (4.7 to 2.7 × 101)6.6 × 104 (3.5 × 104 to 1.1 × 105)3.9 (3.5 to 4.2)8.3 × 104 (2.4 × 104 to 2.0 × 105)4.6 (2.2 to 7.7)
E. coli3.3 × 103 (7.7 × 102 to 1.1 × 104)1.8 × 101 (9.0 × 10−1 to 5.3 × 102)6.7 × 103 (2.3 × 103 to 4.3 × 104)1.1 × 10−2 (<1.0 × 10−2 to 1.3 × 10−2) [66]4.7 × 103 (2.3 × 103 to 1.1 × 104)<1.0 × 10−2 [100]1.5 × 104 (6.3 × 103 to 4.6 × 104)<1.0 × 10−2 [100]
Enterococci8.8 × 102 (5.7 × 102 to 1.3 × 103)2.3 (<1.0 × 10−2 to 4.9 × 101) [33]6.3 × 102 (5.0 × 102 to 8.7 × 102)<1.0 × 10−2 [100]9.9 × 102 (5.3 × 102 to 1.7 × 103)<1.0 × 10−2 [100]1.3 × 103 (7.3 × 102 to 2.3 × 103)<1.0 × 10−2 [100]
Clostridia1.6 × 102 (6.0 × 101 to 3.0 × 102)6.4 (6.7 × 10−1 to 7.7 × 101)2.0 × 102 (7.0 × 101 to 6.0 × 102)7.9 × 10−1 (4.5 × 10−1 to 1.4)3.4 × 101 (2.0 × 101 to 6.3 × 101)2.4 × 10−2 (<1.0 × 10−2 to 6.0 × 10−2) [33]4.4 × 101 (2.7 × 101 to 9.3 × 101)7.4 × 10−2 (<1.0 × 10−2 to 3.6 × 10−1) [33]
Coliphage1.5 × 102 (1.2 × 102 to 2.2 × 102)3.1 × 101 (<1.0 to 1.8 × 102) [33]1.4 × 102 (1.3 × 102 to 1.4 × 102)1.9 × 101 (<1.0 to 1.1 × 102) [33]9.4 × 101 (4.3 × 101 to 1.6 × 102)7.3 (1.3 to 4.7 × 101)7.7 × 101 (4.0 × 101 to 1.2 × 102)<1.0 [100]
Open in a separate windowaValues shown are numbers of CFU/ml except those for coliphage, which are numbers of PFU/ml. The percentage of samples below the detection limit (n = 3 for all systems) is 0% if not shown.All systems were used in accordance with the manufacturer''s directions for 10 liters of water. For NaDCC trials, one tablet was added and allowed 30 min of contact time (total dose of 3.2 mg/liter of hypochlorite; in deionized water, one tablet produced 2.1 mg/liter free Cl residual). For flocculant-disinfectant trials, one packet was added, stirred vigorously for 5 min, strained through cheesecloth after 10 min, and allowed 20 min of further contact time. The amount of hypochlorite included in one packet was not indicated, but one packet provided 1.5 mg/liter free Cl residual in 10 liters of deionized water. Samples were taken at 1, 3, 5, 10, 15, and 30 min for both systems.For the Cl-contact and Br-contact trials, disinfectant cartridges were installed in AquaSure housings consisting of an upper reservoir for influent, which flows by gravity through the disinfectant cartridge to a lower reservoir with a tap for dispensing (Fig. (Fig.1).1). The housings usually include cloth and activated charcoal prefilters, but these were removed in order to directly evaluate the disinfectant. With the tap open, 10 liters of influent was added and samples were collected at first flow (6 to 12 min) and after 15 and 30 min of flow. A single chlorine canister was used for all trials; the bromine canister was replaced for the third trial because the original clogged.Open in a separate windowFIG. 1.Flow schematic for contact disinfectant cartridges. Arrows indicate the directions of water flow from the upper reservoir (U), through the halogen (chlorine or bromine) disinfectant cartridge (H) containing packed N-halamine beads (N), to the lower reservoir (L) and out through the open tap.Microbial indicators in the influent and effluent (collection tubes contained sodium thiosulfate) in triplicate were quantified as numbers of CFU/ml by using mENDO agar for total coliforms (9), mHPC agar for heterotrophic plate counts (8), mTEC medium for E. coli (19), mEI agar for the genus Enterococcus (18), and mCP agar for the genus Clostridium (1) (Becton, Dickinson and Co., Franklin Lakes, NJ). Coliphage (PFU/ml) were measured with a double agar overlay assay, EPA method 1601 (17). Residuals (mg/liter) were measured using a Hach chlorine (free and total) test kit, model CN66 (Hach Co., Loveland, CO) (used for bromine in accordance with Hach method 8016 [10], with the instrument reading multiplied by 2.25 [the ratio of the atomic weights of bromine and chlorine], as advised by Hach Co. technical support).Comparison of water quality levels was done at 30 minutes. LR were calculated, with zeros replaced with the detection limits (Fig. (Fig.2).2). All POU systems reduced microbial concentrations below the detection limit in some trials (Table (Table1),1), making the calculated reductions the lower bound for those trials.Open in a separate windowFIG. 2.Average LR of naturally occurring microorganisms at 30 min for sewage-contaminated well water (1:10 dilution of raw sewage in well water) with the use of four POU disinfection systems (error bars represent 1 standard error). * indicates that effluent was below the limit of detection for all samples. Limit of detection was substituted to calculate LR and actual reductions may be greater than shown.Average LR for each POU system were compared using two-way analysis of variance with post hoc least-significant-difference (LSD) tests, performed with SPSS 11.0.1 (SPSS, Inc.). LR at 30 min differed significantly between systems (analysis of variance; F3,5 = 20.6; P < 0.001). There was no significant difference between the LR achieved by flocculant-disinfectant and contact disinfectants (LSD; mean difference, 0.2 to 0.5 LR; P > 0.05), while the NaDCC tablets induced significantly lower reductions (LSD; mean difference, 1.5 to 2.0 LR; P < 0.001).There was detectable residual free chlorine after 30 min for one NaDCC trial (0.4 mg/liter) and two flocculant-disinfectant trials (0.1 and 0.4 mg/liter). No contact disinfectant trial produced a measurable residual.No system in this study reliably produced residuals for safe storage after POU treatment or ideal virus reduction. Except for the NaDCC system, the POU systems achieved approximately 5.5 LR for E. coli and coliforms, 4.5 LR for enterococci, 4.0 LR for heterotrophs, 2.5 LR for clostridia, and 1.0 LR for coliphage. Coliphage was reduced below detection limits in all trials with Br-contact, similar to what was found in previous research (5). Bromine disinfection has proved safe and effective for large-scale maritime applications, like U.S. Navy vessels (20), and appears promising for household treatment. Further assessment of the Br-contact system is warranted, as is field comparison of POU systems in disaster relief.  相似文献   
37.
RATIONALE AND OBJECTIVES: This article describes issues and methods that are specific to the measurement of change in tumor volume as measured from computed tomographic (CT) images and how these would relate to the establishment of CT tumor volumetrics as a biomarker of patient response to therapy. The primary focus is on the measurement of lung tumors, but the approach should be generalizable to other anatomic regions. MATERIALS AND METHODS: The first issues addressed are the various sources of bias and variance in the measurement of tumor volumes, which are discussed in the context of measurement variation and its impact on the early detection of response to therapy. RESULTS AND RESOURCES: Research that seeks to identify the magnitude of some of these sources of error is ongoing, and several of these efforts are described herein. In addition, several resources for these investigations are being made available through the National Institutes of Health-funded Reference Image Database to Evaluate Response to therapy in cancer project, and these are described as well. Other measures derived from CT image data that might be predictive of patient response are described briefly, as well as the additional issues that each of these metrics may encounter in real-life applications. CONCLUSIONS: The article concludes with a brief discussion of moving from the assessment of measurement variation to the steps necessary to establish the efficacy of a metric as a biomarker for response.  相似文献   
38.

Background  

Tracing cell dynamics in the embryo becomes tremendously difficult when cell trajectories cross in space and time and tissue density obscure individual cell borders. Here, we used the chick neural crest (NC) as a model to test multicolor cell labeling and multispectral confocal imaging strategies to overcome these roadblocks.  相似文献   
39.
1. A P1,P3-bis(5'-nucleosidyl)triphosphate pyrophosphohydrolase (Np3 Nase) has been partially purified from Artemia embryos. 2. The Np3 Nase has a native Mr of 115,000 and preferentially hydrolyses substrates of the form Np3 N. Relative rates of hydrolysis are Ap3A (Vrel = 1.0), Gp3G (Vrel = 0.71), Ap4A (Vrel = 0.08), Ap5A (Vrel = 0.09), Gp4G (Vrel = 0.3) and Gp5G (Vrel = 0.33). An NMP is always one of the products. 3. The Km values for Ap3A and Gp3G are 15 and 10 microM respectively. 4. Mg2+, Mn2+ and Ca2+ ions all stimulate the activity, while Zn2+, Co2+ and Ni2+ ions are inhibitory. 5. The activity of the Np3 Nase remains constant during pre-emergence development of encysted embryos but decreases slightly after hatching.  相似文献   
40.
1. The possible relationship between the fatty acid composition of the adipose tissue of the marmoset monkey (Callithrix jacchus) and its dietary lipid intake was examined after a long-term feeding trial. 2. Only the proportions of stearic and linoleic acid in the adipose tissue were similar to those in the diet. The proportions of all other saturated and unsaturated fatty acid components were significantly different thus greatly reducing the potential value of this relationship in the marmoset. 3. The phospholipid fatty acid profiles of cardiac and skeletal muscle, aortae, kidney, liver, lung and brain were also compared to those of the plasma, platelets or red blood cells. 4. With the exception of the liver where the fatty acid profile is similar to that of the plasma, no clear relationships were found between the fatty acid profiles of these tissues and the components of the blood. 5. The fatty acid composition of skeletal muscle was very similar to that of the cardiac muscle of the marmoset, suggesting that muscle biopsy might be useful as an index of cardiac muscle composition.  相似文献   
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