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61.
Tatsuru Kadota Jun Osato Ken Nagata Yoichi Sakai 《Ethology : formerly Zeitschrift fur Tierpsychologie》2012,118(3):226-234
Bi‐directional sex change has recently been reported in a range of reef fishes, including haremic species that were earlier thought to be protogynous (female to male). However, the occurrence of this phenomenon and the social conditions driving the reversion of males to females (reversed sex change) have been poorly documented under natural conditions. Reversed sex change is predicted to occur in low‐density populations where facultative monogamy is common. However, few studies have evaluated this over a long period in such populations. We documented the occurrence of bi‐directional sex change during a 3‐yr demographic survey of a population characterised by small harem sizes in haremic hawkfish Cirrhitichthys falco. New males were derived following a change in sex of functional females (secondary males; n = 3) and juveniles always matured first as females (n = 3). Thus, C. falco exhibited a typical protogynous sexual pattern, consistent with a range of haremic fish species. We observed reversed sex change in two males. In both cases, all the females disappeared from their harems and the neighbouring males expanded their territories to encompass the territories of the sex changers. However, bachelor males did not always revert to females. A dominant male experienced bachelor status twice but regained mating opportunities following the immigration of a female into his territory or by taking a female from a neighbouring harem. Thus, we conclude that bachelor males use reversed sex change as a facultative tactic to regain reproductive status in a haremic mating system. In addition, we discuss the influence of harem size upon occurrence of reversed sex change. 相似文献
62.
RhoD activated by fibroblast growth factor induces cytoneme-like cellular protrusions through mDia3C
Kazuhisa Koizumi Kazunori Takano Akiko Kaneyasu Haruko Watanabe-Takano Emi Tokuda Tomoyuki Abe Naoki Watanabe Tadaomi Takenawa Takeshi Endo 《Molecular biology of the cell》2012,23(23):4647-4661
The small GTPase RhoD regulates actin cytoskeleton to collapse actin stress fibers and focal adhesions, resulting in suppression of cell migration and cytokinesis. It also induces alignment of early endosomes along actin filaments and reduces their motility. We show here that a constitutively activated RhoD generated two types of actin-containing thin peripheral cellular protrusions distinct from Cdc42-induced filopodia. One was longer, almost straight, immotile, and sensitive to fixation, whereas the other was shorter, undulating, motile, and resistant to fixation. Moreover, cells expressing wild-type RhoD extended protrusions toward fibroblast growth factor (FGF) 2/4/8–coated beads. Stimulation of wild-type RhoD-expressing cells with these FGFs also caused formation of cellular protrusions. Nodules moved through the RhoD-induced longer protrusions, mainly toward the cell body. Exogenously expressed FGF receptor was associated with these moving nodules containing endosome-like vesicles. These results suggest that the protrusions are responsible for intercellular communication mediated by FGF and its receptor. Accordingly, the protrusions are morphologically and functionally equivalent to cytonemes. RhoD was activated by FGF2/4/8. Knockdown of RhoD interfered with FGF-induced protrusion formation. Activated RhoD specifically bound to mDia3C and facilitated actin polymerization together with mDia3C. mDia3C was localized to the tips or stems of the protrusions. In addition, constitutively activated mDia3C formed protrusions without RhoD or FGF stimulation. Knockdown of mDia3 obstructed RhoD-induced protrusion formation. These results imply that RhoD activated by FGF signaling forms cytoneme-like protrusions through activation of mDia3C, which induces actin filament formation. 相似文献
63.
S Nishiumi T Kobayashi A Ikeda T Yoshie M Kibi Y Izumi T Okuno N Hayashi S Kawano T Takenawa T Azuma M Yoshida 《PloS one》2012,7(7):e40459
Background
To improve the quality of life of colorectal cancer patients, it is important to establish new screening methods for early diagnosis of colorectal cancer.Methodology/Principal Findings
We performed serum metabolome analysis using gas-chromatography/mass-spectrometry (GC/MS). First, the accuracy of our GC/MS-based serum metabolomic analytical method was evaluated by calculating the RSD% values of serum levels of various metabolites. Second, the intra-day (morning, daytime, and night) and inter-day (among 3 days) variances of serum metabolite levels were examined. Then, serum metabolite levels were compared between colorectal cancer patients (N = 60; N = 12 for each stage from 0 to 4) and age- and sex-matched healthy volunteers (N = 60) as a training set. The metabolites whose levels displayed significant changes were subjected to multiple logistic regression analysis using the stepwise variable selection method, and a colorectal cancer prediction model was established. The prediction model was composed of 2-hydroxybutyrate, aspartic acid, kynurenine, and cystamine, and its AUC, sensitivity, specificity, and accuracy were 0.9097, 85.0%, 85.0%, and 85.0%, respectively, according to the training set data. In contrast, the sensitivity, specificity, and accuracy of CEA were 35.0%, 96.7%, and 65.8%, respectively, and those of CA19-9 were 16.7%, 100%, and 58.3%, respectively. The validity of the prediction model was confirmed using colorectal cancer patients (N = 59) and healthy volunteers (N = 63) as a validation set. At the validation set, the sensitivity, specificity, and accuracy of the prediction model were 83.1%, 81.0%, and 82.0%, respectively, and these values were almost the same as those obtained with the training set. In addition, the model displayed high sensitivity for detecting stage 0–2 colorectal cancer (82.8%).Conclusions/Significance
Our prediction model established via GC/MS-based serum metabolomic analysis is valuable for early detection of colorectal cancer and has the potential to become a novel screening test for colorectal cancer. 相似文献64.
Motoki Okumura Akifumi Kijima Koji Kadota Keiko Yokoyama Hiroo Suzuki Yuji Yamamoto 《PloS one》2012,7(12)
In many competitive sports, players need to quickly and continuously execute movements that co-adapt to various movements executed by their opponents and physical objects. In a martial art such as kendo, players must be able to skillfully change interpersonal distance in order to win. However, very little information about the task and expertise properties of the maneuvers affecting interpersonal distance is available. This study investigated behavioral dynamics underlying opponent tasks by analyzing changes in interpersonal distance made by expert players in kendo matches. Analysis of preferred interpersonal distances indicated that players tended to step toward and away from their opponents based on two distances. The most preferred distance enabled the players to execute both striking and defensive movements immediately. The relative phase analysis of the velocities at which players executed steps toward and away revealed that players developed anti-phase synchronizations at near distances to maintain safe distances from their opponents. Alternatively, players shifted to in-phase synchronization to approach their opponents from far distances. This abrupt phase-transition phenomenon constitutes a characteristic bifurcation dynamics that regularly and instantaneously occurs between in- and anti-phase synchronizations at a critical interpersonal distance. These dynamics are profoundly affected by the task constraints of kendo and the physical constraints of the players. Thus, the current study identifies the clear behavioral dynamics that emerge in a sport setting. 相似文献
65.
Tetraploid plants of a Japanese pear cultivar (Pyrus pyrifolia N.) were induced using an in vitro colchicine treatment. Proliferating shoots were transferred to a shoot proliferation medium (SPM) containing 0.1% or 0.01% colchicine, incubated for 1, 2, 4 or 8 days, then transferred to fresh SPM. The ploidy level of the colchicine-treated individuals was analysed by flow cytometry. Four months after colchicine treatment four mixoploids were selected and cultured on SPM for a further 5 months. The ploidy level of the proliferated shoots derived from selected mixoploids was analysed, and five tetraploid shoots were selected. The selected tetraploid shoots were rooted, and potted plants were grown in a greenhouse. The stomata of tetraploid plants were found to be longer than those in diploid plants. 相似文献
66.
The expression balance of M2 and M3 muscarinic receptor subtypes on the pathogenesis of airway hyperresponsiveness was investigated by using two congenitally related strains of guinea pigs, bronchial-hypersensitive (BHS) and bronchial-hyposensitive (BHR). CCh-induced airway responses in vivo and in vitro were investigated by comparing the effects of muscarinic receptor subtype antagonists, and the relative amounts of M2 and M3 muscarinic receptor mRNA in tracheal smooth muscle and lung tissue were investigated. After treatment with muscarinic receptor subtype antagonists, the ventilatory mechanics (VT, Raw, and Cdyn) of response to CCh aerosol inhalation were measured by the bodyplethysmograph method. The effects of these antagonists on CCh-induced tracheal smooth muscle contraction were also investigated. The effects of M2 muscarinic receptor blockade were less but the effects of M3 muscarinic receptors blockade on the airway contractile responses were greater in BHS than in BHR. In M3 muscarinic receptor blockades, CCh-induced tracheal contractions in BHS were significantly greater than those in BHR. In tracheal smooth muscle from BHS, the relative amount of M2 muscarinic receptors mRNA was less but that of M3 muscarinic receptor mRNA was more than those in BHR. These results suggest that the high ACh level as a consequence of dysfunction of M2 muscarinic autoreceptors and the excessive effect of M3 muscarinic receptors on the airway smooth muscle may play an important role in the pathogenesis of airway hyperresponsiveness. 相似文献
67.
68.
69.
Kengo Funakoshi Tetsuo Kadota Yoshitoshi Atobe Masato Nakano Richard C. Goris Reiji Kishida 《Cell and tissue research》1999,298(1):45-54
To examine the presence of nitric oxide synthase (NOS) in the sensory system of the glossopharyngeal and vagus nerves of teleosts, nicotinamide adenine dinucleotide phosphate diaphorase (NADPHd) activity and immunoreactivity for NOS were examined in the puffer fish Takifugu niphobles. The nitrergic sensory neurons were located in the ganglia of both the glossopharyngeal and the vagal nerves. In the vagal ganglion, positive neurons were found in the subpopulations for the branchial rami and the coelomic visceral ramus, but not for the posterior ramus or the lateral line ramus. In the medulla, nitrergic afferent terminals were found in the glossopharyngeal lobe, the vagal lobe, and the commissural nucleus. In the gill structure, the nitrergic nerve fibers were seen in the nerve bundles running along the efferent branchial artery of all three gill arches. These fibers appeared to terminate in the proximal portion of the efferent filament arteries of three gill arches. On the other hand, autonomic neurons innervating the gill arches were unstained. These results suggest that nitrergic sensory neurons in the glossopharyngeal and vagal ganglia project their peripheral processes through the branchial rami to a specific portion of the branchial arteries, and they might play a role in baroreception of this fish. A possible role for nitric oxide (NO) in baroreception is also discussed. 相似文献
70.
Prolactin induces MFG-E8 production in macrophages via transcription factor C/EBPβ-dependent pathway
Aziz MM Ishihara S Rumi MA Mishima Y Oshima N Kadota C Moriyama I Li YY Rahman FB Otani A Oka A Ishimura N Kadowaki Y Amano Y Kinoshita Y 《Apoptosis : an international journal on programmed cell death》2008,13(5):609-620
The lactogenic hormone prolactin (PRL) regulates milk protein gene expression in mammary glands. To maintain homeostatic balance
in the body, milk fat globule epidermal growth factor 8 (MFG-E8) is vital for phagocytic clearance of apoptotic cells. We
investigated the effects of PRL on MFG-E8 expression in macrophages by evaluating its promoter function. Macrophages were
stimulated with PRL, and the expression of MFG-E8 was determined using real-time PCR and Western blotting. The role of MFG-E8
on phagocytosis of apoptotic cells in PRL-treated macrophages was assessed using microscopy, while the response of PRL to
MFG-E8 expression was evaluated using luciferase assay. Following treatment with PRL, significant up-regulations of the PRL
receptor and MFG-E8 were observed in macrophages, though PRL-treated macrophages more efficiently engulfed apoptotic cells.
The results of MFG-E8 promoter analysis showed considerable up-regulation of promoter activity in macrophages following PRL
treatment and results from mutation analysis of the MFG-E8 promoter suggested that the C/EBPβ binding site was responsible
for PRL-induced activation of the MFG-E8 promoter. C/EBPβ activity was found to be up-regulated in PRL-treated cells as revealed
by an electrophoretic mobility shift assay (EMSA). In conclusion, PRL is a potent inducer of MFG-E8 expression in macrophages,
while its effect is mediated by the presence of a responsive element in the MFG-E8 promoter. 相似文献