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71.
Kazutami Imai Tsuyoshi Sugio Takanori Tsuchida Tatsuo Tano 《Bioscience, biotechnology, and biochemistry》2013,77(7):1349-1354
Effect of heavy metal ions on the growth and the iron-oxidizing activity of Thiobacillus ferrooxidans were investigated.Cupric, zinc, cadmium, and chromium ions had no effect on the growth and the iron-oxidizing activity of cell suspensions or cell-free extracts of the bacterium in high concentrations (10?3~10?2M). Lead ion delayed the start of the growth slightly in 10?3 M, but it did not inhibit the iron-oxidizing activity of the cells in the concentration. Tin and molybdenum oxide ions inhibited both of them in the concentration above 10?3 M.Mercuric mercurous, and silver ions had the most harmful effect. In the concentration of 10?3 .M, each of the cations inhibited almost completely both the growth and the iron-oxidizing activity of the cells.In the experiments with cell-free extracts it was observed that the activity of cytochrome oxidase (cytochrome a597) operating in the iron-oxidizing system of the bacterium was specifically inhibited with mercuric ion in the concentration above 5 × 10?4 M. 相似文献
72.
Tsuyoshi Fujitani 《Bioscience, biotechnology, and biochemistry》2013,77(9):925-930
The critical concentrations of minerals in a growing medium for maximum fermentation of yeast were as follows: P, 1 mmol/1; Mg, 0.2 mmol/1; and K, 1~2 mmol/1. These values are lower than those for the saturation of the cells with each mineral. The order of the concentration for maximum fermentation (K>P>Mg) is in agreement with that for yeast growth.Only a small amount of mineral salt was required to increase the fermentative activity. Very small increase of fermentative activity was observed when the starved yeast was enriched with corresponding minerals by incubating cells with the mineral salt and glucose. 相似文献
73.
Yoshiki Tani Koichi Ogata Masao Ukita Tsuyoshi Nakamatsu Yoshikazu Izumi 《Bioscience, biotechnology, and biochemistry》2013,77(2):173-197
Escherichia freundii alkaline phosphatase was found in a membrane fraction and was purified by procedures involving spheroplast formation with lysozyme and EDTA, and DEAE-cellulose and Sephadex G-150 column chromatographies. Then this enzyme along with other phosphatases was investigated on the ability to transfer the phosphoryl group from p-nitrophenyl phosphate to pyridoxine. It was found that the ability of the transphosphorylation varied with these phosphatases. The transphosphorylation to hydroxy compounds such as alcohols, sugars and nucleosides was also compared. Escherichia freundii acid phosphatase showed the highest activity of transphosphorylation among phosphatases tested. The mechanism of transphosphorylation was discussed.An enzyme, pyridoxamine 5′-phosphate transaminase, was purified from the cell-free extract of Clostridium kainantoi. The purification procedures involved ammonium sulfate fractionation, protamine sulfate treatment and, DEAE-cellulose, hydroxylapatite, DEAE-Sephadex and Sephadex G-200 column chromatographies. The purified enzyme, which had approximately 2700-fold higher specific activity over the original extract, showed a single schlieren pattern in the ultracentrifuge. From the spectral analysis, it seemed that pyridoxamine 5′-phosphate transaminase did not contain pyridoxal 5′-phosphate as a prosthetic group. It was recognized that the transamination was accelerated by the addition of amino acid and was inhibited by diisopropyl phosphofluoride. Glutamic acid formed in the reaction was identified to be a D-isomer. A study on the substrate specificity showed that the enzyme might be possible to be specific for pyridoxamine 5′-phosphate.The extracellular formation of vitamin B6 was searched in marine and terrestrial microorganisms. Two bacterial strains were selected and were identified as Vibrio and Flavobacterium, respectively. Marine microorganisms showed the considerable formation of vitamin B6 and the presence of vitamin B6 in sea water was also recognized. The cultural and reaction conditions for vitamin B6 formation by these strains were investigated. Glycerol was commonly the most effective compound on vitamin B6 formation among the compounds tested. It was suggested that both bacteria did not have the control system on vitamin B6 biosynthesis by the amount of possible end products. 相似文献
74.
Haruya Takahashi Kosuke Kamakari Hideyuki Suzuki Shinsuke Mohri Tsuyoshi Goto Nobuyuki Takahashi 《Bioscience, biotechnology, and biochemistry》2013,77(10):1761-1764
We previously reported that the two peroxisome proliferator-activated receptor-α agonists, 9- and 13-oxo-octadecadienoic acids (oxo-ODAs), were found in the tomato fruit. However, their localization remains unknown. Herein, we showed that oxo-ODAs localize primarily in the fruit peel and their amount increases after the homogenization of the tomato fruit. 相似文献
75.
Asaka Takahashi Tsuyoshi Yamada Yohei Uchiyama Satomi Hayashi Kei Kumakura Hitoe Takahashi 《Bioscience, biotechnology, and biochemistry》2013,77(9):1512-1517
2-[3-(2-Thioxopyrrolidin-3-ylidene)methyl]-tryptophan (TPMT) is a yellow pigment of salted radish roots (takuan-zuke) derived from 4-methylthio-3-butenyl isothiocyanate (MTBITC), the pungent component of radish roots. Here, we prepared salted radish and analyzed the behavior of the yellow pigment and related substances in the dehydration process and long-term salting process. All salted radish samples turned yellow, and their b* values increased with time and temperature. The salted radish that was sun-dried and pickled at room temperature turned the brightest yellow, and the generation of TPMT was clearly confirmed. These results indicate that tissue shrinkage due to dehydration, salting temperature, and pH play important roles in the yellowing of takuan-zuke. 相似文献
76.
Huifang Hao Yutaka Maeda Takuya Fukazawa Tomoki Yamatsuji Munenori Takaoka Xiao-Hong Bao Junji Matsuoka Tatsuo Okui Tsuyoshi Shimo Nagio Takigawa Yasuko Tomono Motowo Nakajima Iris M. Fink-Baldauf Sandra Nelson William Seibel Ruben Papoian Jeffrey A. Whitsett Yoshio Naomoto 《PloS one》2013,8(8)
Midkine (MDK) is a heparin-binding growth factor that is highly expressed in many malignant tumors, including lung cancers. MDK activates the PI3K pathway and induces anti-apoptotic activity, in turn enhancing the survival of tumors. Therefore, the inhibition of MDK is considered a potential strategy for cancer therapy. In the present study, we demonstrate a novel small molecule compound (iMDK) that targets MDK. iMDK inhibited the cell growth of MDK-positive H441 lung adenocarcinoma cells that harbor an oncogenic KRAS mutation and H520 squamous cell lung cancer cells, both of which are types of untreatable lung cancer. However, iMDK did not reduce the cell viability of MDK-negative A549 lung adenocarcinoma cells or normal human lung fibroblast (NHLF) cells indicating its specificity. iMDK suppressed the endogenous expression of MDK but not that of other growth factors such as PTN or VEGF. iMDK suppressed the growth of H441 cells by inhibiting the PI3K pathway and inducing apoptosis. Systemic administration of iMDK significantly inhibited tumor growth in a xenograft mouse model in vivo. Inhibition of MDK with iMDK provides a potential therapeutic approach for the treatment of lung cancers that are driven by MDK. 相似文献
77.
Kei A. Sato Tsuyoshi Hachiya Takeshi Iwaya Kohei Kume Teppei Matsuo Keisuke Kawasaki Yukito Abiko Risaburo Akasaka Takayuki Matsumoto Koki Otsuka Satoshi S. Nishizuka 《PloS one》2016,11(1)
Background
Circulating tumor DNA (ctDNA) carries information on tumor burden. However, the mutation spectrum is different among tumors. This study was designed to examine the utility of ctDNA for monitoring tumor burden based on an individual mutation profile.Methodology
DNA was extracted from a total of 176 samples, including pre- and post-operational plasma, primary tumors, and peripheral blood mononuclear cells (PBMC), from 44 individuals with colorectal tumor who underwent curative resection of colorectal tumors, as well as nine healthy individuals. Using a panel of 50 cancer-associated genes, tumor-unique mutations were identified by comparing the single nucleotide variants (SNVs) from tumors and PBMCs with an Ion PGM sequencer. A group of the tumor-unique mutations from individual tumors were designated as individual marker mutations (MMs) to trace tumor burden by ctDNA using droplet digital PCR (ddPCR). From these experiments, three major objectives were assessed: (a) Tumor-unique mutations; (b) mutation spectrum of a tumor; and (c) changes in allele frequency of the MMs in ctDNA after curative resection of the tumor.Results
A total of 128 gene point mutations were identified in 27 colorectal tumors. Twenty-six genes were mutated in at least 1 sample, while 14 genes were found to be mutated in only 1 sample, respectively. An average of 2.7 genes were mutated per tumor. Subsequently, 24 MMs were selected from SNVs for tumor burden monitoring. Among the MMs found by ddPCR with > 0.1% variant allele frequency in plasma DNA, 100% (8 out of 8) exhibited a decrease in post-operation ctDNA, whereas none of the 16 MMs found by ddPCR with < 0.1% variant allele frequency in plasma DNA showed a decrease.Conclusions
This panel of 50 cancer-associated genes appeared to be sufficient to identify individual, tumor-unique, mutated ctDNA markers in cancer patients. The MMs showed the clinical utility in monitoring curatively-treated colorectal tumor burden if the allele frequency of MMs in plasma DNA is above 0.1%. 相似文献78.
79.
Al‐Sayed Al‐Soudy Tsuyoshi Nakanishi Seiya Mizuno Yoshikazu Hasegawa Hossam H. Shawki Megumi C. Katoh Walaa A. Basha Abdelaziz E. Ibrahim Hany A. El‐Shemy Hiroyoshi Iseki Atsushi Yoshiki Youhei Hiromori Hisamitsu Nagase Satoru Takahashi Hisashi Oishi Fumihiro Sugiyama 《Genesis (New York, N.Y. : 2000)》2016,54(7):389-397
Spermatogenesis is a complex and highly regulated process by which spermatogonial stem cells differentiate into spermatozoa. To better understand the molecular mechanisms of the process, the Cre/loxP system has been widely utilized for conditional gene knockout in mice. In this study, we generated a transgenic mouse line that expresses Cre recombinase under the control of the 2.5 kbp of the Prolactin family 3, subfamily b, member 1 (Prl3b1) gene promoter (Prl3b1‐cre). Prl3b1 was initially reported to code for placental lactogen 2 (PL‐2) protein in placenta along with increased expression toward the end of pregnancy. PL‐2 was found to be expressed in germ cells in the testis, especially in spermatocytes. To analyze the specificity and efficiency of Cre recombinase activity in Prl3b1‐cre mice, the mice were mated with reporter R26GRR mice, which express GFP ubiquitously before and tdsRed exclusively after Cre recombination. The systemic examination of Prl3b1‐cre;R26GRR mice revealed that tdsRed‐positive cells were detected only in the testis and epididymis. Fluorescence imaging of Prl3b1‐cre;R26GRR testes suggested that Cre‐mediated recombination took place in the germ cells with approximately 74% efficiency determined by in vitro fertilization. In conclusion, our results suggest that the Prl3b1‐cre mice line provides a unique resource to understand testicular germ‐cell development. genesis 54:389–397, 2016. © 2016 Wiley Periodicals, Inc. 相似文献
80.
Taketo Uchiyama Norifumi Tatsumi Sahoko Kamejima Tsuyoshi Waku Ichiro Ohkido Keitaro Yokoyama Takashi Yokoo Masataka Okabe 《Human cell》2016,29(4):155-161
Chronic kidney disease (CKD) disrupts mineral homeostasis and its representative pathosis is defined as secondary hyperparathyroidism (SHPT). SHPT occurs during the early course of progressive renal insufficiency, and is associated with mortality and cardiovascular events. SHPT results in reduction of calcium-sensing receptor (CaSR) and vitamin D receptor (VDR) in the parathyroid glands during CKD. However, the precise mechanism of CaSR and VDR reduction is largely unknown. CKD was induced through two-step 5/6 nephrectomy, and then CKD rats and sham-operated rats were maintained for 8 weeks on diets containing 0.7 % phosphorus (normal phosphate) or 1.2 % phosphorus (high phosphate). In gene expression analysis, TaqMan probes were used for quantitative real-time polymerase chain reaction. Finally, CaSR and VDR protein expressions were analyzed using immunohistochemistry. DNA methylation analysis was performed using a restriction digestion and quantitative PCR. CaSR and VDR mRNA were reduced only in CKD rats fed the high-phosphorus diets (CKD HP), then CaSR and VDR immunohistochemical expressions were compatible with gene expression assay. SHPT was then confirmed only in CKD HP rats. Furthermore, sole CKD HP rats showed the hypermethylation in CaSR and VDR genes; however, the percentage methylation of both genes was low. Although CaSR and VDR hypermethylation was demonstrated in PTGs of CKD HP rats, the extent of hypermethylation was insufficient to support the relevance between hypermethylation and down-regulation of gene expression because of the low percentage of methylation. Consequently, our data suggest that mechanisms, other than DNA hypermethylation, were responsible for the reduction in mRNA and protein levels of CaSR and VDR in PTGs of CKD HP rats. 相似文献