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401.
Cakmak Karaer Isil Günes Nalan Firat Hikmet Yoldas Tahir Caylan Refik Ensari Nuray Dagli Muharrem 《Sleep and biological rhythms》2019,17(4):441-445
Sleep and Biological Rhythms - The aim of the study was to evaluate whether there was a problem in the interneuronal junctions of patients with central sleep apnea using the blink reflex test.... 相似文献
402.
Iqbal Tahir Khalil Saba Ijaz Mohsin Riaz Khalid Nadeem Khan Muhammad Isa Shakil Muhammad Nabi Azeem Ghulam Javaid Muhammad Abrar Muhammad Afsheen Sumera 《Plasmonics (Norwell, Mass.)》2019,14(3):775-783
Plasmonics - The present work investigates the effect of geometrical parameters of 1D nanograting on surface plasmon resonance (SPR) and plasmonic bandgap (PBG). The use of plasmonic grating device... 相似文献
403.
Claudia A. Blindauer M. Tahir Razi Dominic J. Campopiano Peter J. Sadler 《Journal of biological inorganic chemistry》2007,12(3):393-405
The cyanobacterial metallothionein (MT) SmtA is the prototype for bacterial MTs and protects against elevated levels of zinc. In contrast to mammalian MTs, bacterial MTs coordinate to metal ions not only via cysteine sulfurs, but unusually for MTs, also via histidine nitrogens. To investigate whether histidine coordination in these metal-sulfur clusters provides advantages over S-coordination only, we mutated the two metal-binding histidine residues in the cyanobacterial MT SmtA from Synechococcus PCC7942 to cysteines. We show that the mutant proteins are still capable of binding up to four zinc ions as is the wild-type protein. However, the mutations perturb protein folding and metal-binding dynamics. Interestingly, several homologues of SmtA also show variations in these two residues. We conclude that histidine residues in Synechococcus PCC7942 SmtA have a stabilising effect due to electrostatic interactions that impact on protein folding and metal cluster charge, and are involved in fine-tuning the reactivity of the bound metal ions. 相似文献
404.
Abdullah Furrukh Mehmood Iram Shahzadi Zain Ali Madiha Islam Muhammad Naeem Bushra Mirza Peter J. Lockhart Ibrar Ahmed Mohammad Tahir Waheed 《植物分类学报:英文版》2021,59(2):388-402
The co‐occurrence of mutational events including substitutions and insertions–deletions (InDels) with oligonucleotide repeats has previously been reported for a limited number of prokaryotic, eukaryotic, and organelle genomes. In this study, the correlations among these mutational events in chloroplast genomes of species in the eudicot family Malvaceae were investigated. This study also reported chloroplast genome sequences of Hibiscus mutabilis, Malva parviflora, and Malvastrum coromandelianum. These three genomes and 16 other publicly available chloroplast genomes from 12 genera of Malvaceae were used to calculate the correlation coefficients among the mutational events at family, subfamily, and genus levels. In these comparisons, chloroplast genomes were pairwise aligned to record the substitutions and the InDels in mutually exclusive, 250nucleotide long bins. Taking one among the two genomes as a reference, the coordinate positions of oligonucleotide repeats in the reference genome were recorded. The extent of correlations among repeats, substitutions, and InDels was calculated and categorized as follows: very weak (0.1–0.19), weak (0.20–0.29), moderate (0.30–0.39), and strong (0.4–0.69). The extent of correlations ranged 0.201–0.6 between “InDels and single‐nucleotide polymorphism (SNP)”, 0.182–0.513 between “InDels and repeat” and 0.055–0.403 between “SNPs and repeats”. At family‐ and subfamily‐level comparisons, 88%–96% of the repeats showed co‐occurrence with SNPs, whereas at the genus level, 23%–86% of the repeats co‐occurred with SNPs in same bins. Our findings support the previous hypothesis suggesting the use of oligonucleotide repeats as a proxy for finding the mutational hotspots. 相似文献
405.
Akbar Tahir Khusnul Yaqin Muhammad Lukman 《International journal of phytoremediation》2021,23(1):64-71
Abstract The objective of this study was to investigate the effect of increasing CO2 concentration on the growth and the capability of Tetraselmis chui. in removal of nitrate, ammonium and phosphate from shrimp pond wastewater (SPWW). The factorial experimental design was used with the treatment of SPWW percentage in culture medium, namely: 100% SPWW, 75% SPWW + 25% Sea Water (SW) and 75% SW + 25% SPWW coupled with three CO2 concentration treatments: 390?ppm, 550?ppm and 1000?ppm using CO2 system. Growth of T. chui. for lengh of cultivation period tended to be higher at treatments of 390?ppm CO2 and 100% SPWW, however there was a declining growth over period of cultivation for both treatments. The growth rate of T. chui was higher for all percentage of SPWW treatments in culture medium at 390?ppm CO2 concentration compared to other percentage of SPWW treatments and CO2 concentration treatments. There was a decreasing of growth rate with increasing CO2 concentration at 100% SPWW and 75% SPWW + 25% SW in culture medium. Nitrogen removal efficiency and removal rate by T. chui. were strongly affected by CO2 concentration. However, there was no significant effect of increasing CO2 concentration to removal efficiency and rate of PO4 by T. chui. 相似文献
406.
Muhammad Nazir Tahir Eunae Cho Petra Mischnick Jae Yung Lee Jae-Hyuk Yu Seunho Jung 《Bioprocess and biosystems engineering》2014,37(4):687-695
In this study, serine protease (subtilisin Carlsberg) was immobilized on pentynyl dextran (PyD, O–alkynyl ether of dextran, 1) and used for the transesterification of N-acetyl-l-phenylalanine ethyl ester (2) with different aliphatic (1-propanol, 1-butanol, 1-pentanol, 1-hexanol) and aromatic (benzyl alcohol, 2-phenyl ethanol, 4-phenyl-1-butanol) alcohols in tetrahydrofuran (THF). The effect of carbon chain length in aliphatic and aromatic alcohols on initial and average transesterification rate, transesterification activity of immobilized enzyme and yield of the reaction under selected reaction conditions was investigated. The transesterification reactivity of the enzyme and yield of the reaction increased as the chain length of the alcohols decreased. Furthermore, almost no change in yield was observed when the immobilized enzyme was repeatedly used for selected alcohols over six cycles. Intrinsic fluorescence analysis showed that the catalytic activity of the immobilized enzyme in THF was maintained due to retention of the tertiary structure of the enzyme after immobilization on PyD (1). 相似文献
407.
Ghulam Mustafa Aisha Tahir Muhammad Asgher Mehboob-ur Rahman Amer Jamil 《Bioinformation》2014,10(1):1-7
A mutation was induced in Aspergillus niger wild strain using ethidium bromide resulting in enhanced expression of citric acid by
three folds and 112.42 mg/mL citric acid was produced under optimum conditions with 121.84 mg/mL of sugar utilization.
Dendograms of 18S rDNA and citrate synthase from different fungi including sample strains were made to assess homology
among different fungi and to study the correlation of citrate synthase gene with evolution of fungi. Subsequent comparative
sequence analysis revealed strangeness between the citrate synthase and 18S rDNA phylogenetic trees. Furthermore, the citrate
synthase movement suggests that the use of traditional marker molecule of 18S rDNA gives misleading information about the
evolution of citrate synthase in different fungi as it has shown that citrate synthase gene transferred independently among different
fungi having no evolutionary relationships. Random amplified polymorphic DNA (RAPD-PCR) analysis was also employed to
study genetic variation between wild and mutant strains of A. niger and only 71.43% similarity was found between both the
genomes. Keeping in view the importance of citric acid as a necessary constituent of various food preparations, synthetic
biodegradable detergents and pharmaceuticals the enhanced production of citric acid by mutant derivative might provide
significant boost in commercial scale viability of this useful product.
Abbreviations
CS - Citrate synthase, CA - Citric acid, RAPD - Random amplified polymorphic DNA, TAF - Total amplified fragments, PAF - Polymorphic amplified fragments, CAF - Common amplified fragments. 相似文献408.
Tayyaba Huma Arooma Maryam Shahid ur Rehman Muhammad Tahir ul qamar Tayyaba Shaheen Asma Haque Bushra Shaheen 《Bioinformation》2014,10(7):443-448
Alpha amylase family is generally defined as a group of enzymes that can hydrolyse and transglycosylase α-(1, 4) or α-(1, 6)
glycosidic bonds along with the preservation of anomeric configuration. For the comparative analysis of alpha amylase family,
nucleotide sequences of seven thermo stable organisms of Kingdom Archea i.e. Pyrococcus furiosus (100-105°C), Kingdom
Prokaryotes i.e. Bacillus licheniformis (90-95°C), Geobacillus stearothermophilus (75°C), Bacillus amyloliquefaciens (72°C), Bacillus subtilis
(70°C) and Bacillus KSM K38 (55°C) and Eukaryotes i.e. Aspergillus oryzae (60°C) were selected from NCBI. Primary structure
composition analysis and Conserved sequence analysis were conducted through Bio Edit tools. Results from BioEdit shown only
three conserved regions of base pairs and least similarity in MSA of the above mentioned alpha amylases. In Mega 5.1 Phylogeny
of thermo stable alpha amylases of Kingdom Archea, Prokaryotes and Eukaryote was handled by Neighbor-Joining (NJ) algorithm.
Mega 5.1 phylogenetic results suggested that alpha amylases of thermo stable organisms i.e. Pyrococcus furiosus (100-105°C), Bacillus
licheniformis (90-95°C), Geobacillus stearothermophilus (75°C) and Bacillus amyloliquefaciens (72°C) are more distantly related as
compared to less thermo stable organisms. By keeping in mind the characteristics of most thermo stable alpha amylases novel and
improved features can be introduced in less thermo stable alpha amylases so that they become more thermo tolerant and
productive for industry. 相似文献
409.
Doroteya Raykova Joakim Klar Aysha Azhar Tahir Naeem Khan Naveed Altaf Malik Muhammad Iqbal Muhammad Tariq Shahid Mahmood Baig Niklas Dahl 《PloS one》2014,9(4)
Pure hair and nail ectodermal dysplasia (PHNED) comprises a heterogeneous group of rare heritable disorders characterized by brittle hair, hypotrichosis, onychodystrophy and micronychia. Autosomal recessive (AR) PHNED has previously been associated with mutations in either KRT85 or HOXC13 on chromosome 12p11.1-q14.3. We investigated a consanguineous Pakistani family with AR PHNED linked to the keratin gene cluster on 12p11.1 but without detectable mutations in KRT85 and HOXC13. Whole exome sequencing of affected individuals revealed homozygosity for a rare c.821T>C variant (p.Phe274Ser) in the KRT74 gene that segregates AR PHNED in the family. The transition alters the highly conserved Phe274 residue in the coil 1B domain required for long-range dimerization of keratins, suggesting that the mutation compromises the stability of intermediate filaments. Immunohistochemical (IHC) analyses confirmed a strong keratin-74 expression in the nail matrix, the nail bed and the hyponychium of mouse distal digits, as well as in normal human hair follicles. Furthermore, hair follicles and epidermis of an affected family member stained negative for Keratin-74 suggesting a loss of function mechanism mediated by the Phe274Ser substitution. Our observations show for the first time that homozygosity for a KRT74 missense variant may be associated with AR PHNED. Heterozygous KRT74 mutations have previously been associated with autosomal dominant woolly hair/hypotrichosis simplex (ADWH). Thus, our findings expand the phenotypic spectrum associated with KRT74 mutations and imply that a subtype of AR PHNED is allelic with ADWH. 相似文献
410.
Flower senescence: some molecular aspects 总被引:1,自引:0,他引:1