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81.
Muhammad Asad Rashad Rasool Khan Ahmed B. Aljuboory Muhammad Haroon U. Rashid Uttam Kumar Inzamam Ul Haq Aqsa Hafeez Ahmed Noureldeen Khadiga Alharbi 《Phyton》2023,92(4):1161-1172
The beet armyworm (BAW), Spodoptera exigua (Lepidoptera: Noctuidae) is a highly destructive pest of vegetables and
field crops. Management of beet armyworm primarily relies on synthetic pesticides, which is threatening the beneficial
community and environment. Most importantly, the BAW developed resistance to synthetic pesticides with making it
difficult to manage. Therefore, alternative and environment-friendly pest management tactics are urgently required.
The use of pesticidal plant extracts provides an effective way for a sustainable pest management program. To evaluate
the use of pesticidal plant extracts against BAW, we selected six plant species (Lantana camara, Aloe vera, Azadirachta
indica, Cymbopogon citratus, Nicotianatabacum, and Ocimum basilicum) for initial screening experiment. Four out of
six plant species such as A. indica, N. tabacum, C. citratus and O. basilicum showed promising mortality of more than
50%. Therefore, we selected these four plant extracts for the subsequent experiments. Through contact bioassay, A.
indica showed high mortality 66.63%, followed by the N. tabacum 53.33%, at 10% w/v concentration. Similarly, N.
tabacum showed the highest mortality rate, 66% at 10% w/v concentration, followed by the A. indica 46% through
feeding bioassay. Furthermore, the feeding deterrence assay showed that C. citratus had a high antifeedant index
(−50) followed by A. indica (−39), and N. tabacum (−28). In living plant assay, the N. tabacum extract showed a
low mean damage score 3.6 on living cotton plant followed by C. citratus 4.5 and A. indica 5.5. Hence, extracts of
three plant species provided promising results against the BAW, which can minimize the use of synthetic chemicals,
particularly for small landholding farmers. Further studies are also required to evaluate the effects of these plant extract
against BAW on cotton plants under field conditions to optimize the further use. 相似文献
82.
We have shown previously that the β-adrenergic agonist isoproterenol (2μM) and the phosphodiesterase inhibitor isobutylmethylxanthine (1 mM) produce a much greater increase in cyclic AMP in human leukocytes that have been pretreated with colchicine (or with other agents that affect microtubule assembly) than in control leukocytes. The effects of colchicines were both time- and dose-dependant. These and other data suggested that the generation of cyclic AMP is normally restricted by an intact system of cytoplasmic microtubules. If so, then the same time and dose dependencies might apply to other colchicines-induced changes in leukocyte function. We have now assayed the distribution of concanavalin A (Con A)-receptor complexes on the leukocyte membrane, taking into account that leukocytes competent to assemble microtubules show a uniform distribution of surface- bound Con A whereas microtubule-deficient cells accumulate Con A in surface caps. We have found that the effect of colchicine on capping is also both time- and dose dependent, and that the dose-response relationships conform to those required to increase cyclic AMP levels. These findings provide further evidence that both colchicine-induced Con-A capping and colchicine- induced cyclic AMP generation depend upon the relaxation of constraints normally imposed by cytoplasmic microtubules upon the plasma membrane, which limit, respectively, lateral mobility of the lectin-receptor complexes, and expression of hormone-sensitive adenylate cyclase. Moreover, colchicine-induced Con-A cap formation is not affected even by very large changes in leukocyte cyclic AMP levels. Thus, elevated cyclic AMP levels do not appear to promote the dissolution of microtubules; rather, the dissolution of microtubules permits the generation of increased amounts of cyclic AMP. 相似文献
83.
BACKGROUND: Ghrelin derives from endocrine cells (A-like cells) in the stomach (mainly the oxyntic mucosa). Its concentration in the circulation increases during fasting and decreases upon re-feeding. This has fostered the notion that the absence of food in the upper gastrointestinal (GI) tract stimulates the secretion of ghrelin. The purpose of the present study was to determine the concentration of ghrelin in serum and oxyntic mucosa after replacing food with intravenous (iv) infusion of nutrients for 8 days using the technique known as total parenteral nutrition (TPN) MATERIALS AND METHODS: Male Sprague-Dawley rats (200-250 g) were given nutrients (lipids, glucose, amino acids, minerals and vitamins) by iv infusion for 8 days during which time they were deprived of food and water; another group was deprived of food for 24-48 h (fasted controls), while fed controls had free access to food and water. Serum ghrelin, gastrin and pancreastatin concentrations were measured together with the ghrelin content of the oxyntic mucosa. Plasma insulin and glucose as well as serum lipid concentrations were also determined. RESULTS: Fasted rats had higher serum ghrelin than TPN rats and fed controls. The oxyntic mucosal ghrelin concentration (and content) was lower in TPN rats than in fasted rats or fed controls. The serum gastrin and pancreastatin concentrations were lower in TPN rats and fasted rats than in fed controls. The plasma insulin concentration was 87 pmol/l+/-8 (SEM) in TPN rats compared to 101+/-16 pmol/l in fed controls; it was 26+/-14 pmol/l in fasted rats. The basal plasma glucose level was 11+/-0.6 mmol/l in TPN rats and 12+/-0.8 mmol/l in fed controls; it was 7+/-0.3 mmol/l in fasted rats. In TPN rats, the serum concentrations of free fatty acids, triglycerides and cholesterol were increased by 100%, 50% and 25%, respectively, compared to fed controls. Fasted rats had higher circulating concentrations of free fatty acids (20%) and lower concentrations of triglycerides (-40%) than fed controls; fasted rats did not differ from fed controls with respect to serum cholesterol. CONCLUSION: The circulating ghrelin concentration is high in situations of nutritional deficiency (starvation) and low in situations of nutritional plenty (free access to food or TPN). The actual presence or absence of food in the GI tract seems irrelevant. Circulating insulin and glucose concentrations did not differ much between TPN rats and fed controls; serum lipids, however, were elevated in the TPN rats. We suggest that elevated blood lipid levels contribute to the suppression of circulating ghrelin in rats subjected to TPN for 8 days. 相似文献
84.
豆科黄华属植物种子表面特征的研究 总被引:2,自引:0,他引:2
在扫描电镜下观察了豆科黄华属Thermopsis 18种植物种子的表面纹饰,发现 T.alpina,T.bar-
bata,T.inflata,T.lupinoides,T. licentiana,T.smithiana和T.turkestanica的种子表面为粗网状,T
californica,T.divaricarpa,T. macrophylla,T.mollis的种子表面为细网状,T.gracilis,T.montana,T.
fabacea的种子表面为相对平滑型纹饰,T.alterniflora的种子表面为不规则条形,T.chinensis的种子表
面为粘膜状,T.rhombifolia的种子表面为条形及 T.viuosa的种子表面为碎屑状纹饰。结果表明黄华属的种子表面特征对属下类群的划分有一定意义,对澄清某些混乱的种有一定价值。 相似文献
85.
86.
A. M. Ul’yanov L. A. Lyapina T. Yu. Obergan T. A. Shubina V. E. Pastorova L. A. Andreeva N. F. Myasoedov I. P. Ashmarin 《Biology Bulletin》2009,36(6):630-633
It was shown that chronic (over 7 days) intranasal injection of the Pro-Gly-Arg tripeptide to rats in the dose 1 mg/kg before
the injection of a diabetogenic dose of alloxan, promotes effective defense against development of insulin dependent diabetes
mellitus. At the same time, the tetra-peptide Pro-Gly-Pro-Arg did not show a hypoglycemic affect during diabetes mellitus
provocation. Administration of Pro-Gly-Arg and Pro-Gly-Pro-Arg peptides also activates anticoagulation potential. 相似文献
87.
Muhammad Asif Nawaz Haneef Ur Rehman Zainab Bibi Afsheen Aman Shah Ali Ul Qader 《Biochemistry and Biophysics Reports》2015
Maltase from Bacillus licheniformis KIBGE-IB4 was immobilized within calcium alginate beads using entrapment technique. Immobilized maltase showed maximum immobilization yield with 4% sodium alginate and 0.2 M calcium chloride within 90.0 min of curing time. Entrapment increases the enzyme–substrate reaction time and temperature from 5.0 to 10.0 min and 45 °C to 50 °C, respectively as compared to its free counterpart. However, pH optima remained same for maltose hydrolysis. Diffusional limitation of substrate (maltose) caused a declined in Vmax of immobilized enzyme from 8411.0 to 4919.0 U ml?1 min?1 whereas, Km apparently increased from 1.71 to 3.17 mM ml?1. Immobilization also increased the stability of free maltase against a broad temperature range and enzyme retained 45% and 32% activity at 55 °C and 60 °C, respectively after 90.0 min. Immobilized enzyme also exhibited recycling efficiency more than six cycles and retained 17% of its initial activity even after 6th cycles. Immobilized enzyme showed relatively better storage stability at 4 °C and 30 °C after 60.0 days as compared to free enzyme. 相似文献
88.
Shyamashree Banerjee Parth Sarthi Sen Gupta Arnab Nayek Sunit Das Vishma Pratap Sur Pratyay Seth Rifat Nawaz Ul Islam Amal K Bandyopadhyay 《Bioinformation》2015,11(7):366-368
AvailabilityPHYSICO2: is freely available at http://sourceforge.net/projects/physico2/ along with its documentation at
https://sourceforge.net/projects/physico2/files/Documentation.pdf/download for all users. 相似文献
89.
Abstract E. coliβ-glucuronidase, a cytosolic enzyme, was found not to be a good reporter enzyme for secretion studies in plants. In this study, we chose to test and adapt an animal β-glucuronidase as a better reporter protein for the secretory pathway of plants. We modified rat β-glucuronidase to obtain secreted and vacuolar variants. Five different C-termini were produced: the original C-terminus of the rat enzyme, a 19 codon deletion (Δ19), a 15 codon deletion (Δ15) and fusions of the Δ19 or Δ15 termini with the last 6 or 7 codons of the vacuolar sorting determinant of tobacco chitinase A, respectively. The signal sequence of the rat β-glucuronidase polypeptide was replaced by the sequence encoding the signal peptide of tobacco chitinase A. In a transient expression system, the best enzymatic activity was found with β-glucuronidase having the 15 codons deletion, therefore Δ15 (secRGUS) and Δ15 + Chi (RGUS-Chi) were further evaluated and their efficiency of secretion or vacuolar targeting were tested under different conditions. To determine the correct targeting of reporter genes, we compared the localization of β-glucuronidase and of an endogenous marker, α-mannosidase. Treating cells with drugs that specifically affect different aspects of the secretory pathway also tested the validity of RGUS-based reporters. A non-specific inhibitor such as cytochalasin D and a wide range inhibitor such as BFA were compared with specific inhibitors such as wortmannin and bafilomycin A1. Finally, monensin and NH4Cl were used to evaluate the role of vacuolar pH in correct RGUS-Chi targeting. The two new reporter proteins proved to be good tools for our studies in the transient expression system in tobacco protoplasts and for further applications. 相似文献
90.
A nonisothermal model of the positive column allowing for electron energy balance is analyzed. The influence of the axial magnetic field on the characteristics of the cylindrical positive column of a low-pressure discharge is investigated in the hydrodynamic approximation. It is shown that the magnetic field affects the plasma density distribution, plasma velocity, and electron energies. The radial dependences of the plasma density, electron energy, and plasma velocity, as well as the azimuthal velocities of electrons and ions, are calculated for helium at different values of the magnetic field strength. It is established that inertia should be taken into account in the equations for the azimuthal motion of electrons and ions. The results obtained in the hydrodynamic approximation differ significantly from those obtained in the framework of the common diffusion model of the positive column in the axial magnetic field. It is shown that the distributions of the plasma density and radial plasma velocity in the greater part of the positive column tend to those obtained in the diffusion approximation at higher values of the axial magnetic field and gas density, although substantial differences remain in the near-wall region. 相似文献