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采用珠磨法、冻融研磨法和酶法对粪便细菌进行裂解,提取粪便细菌DNA,并采用16SrRNAV3区引物(P3GCf、P2r)和V6V8区引物(U968GCf、L1401r)扩增细菌16SrRNA基因可变区,对变性梯度凝胶电泳(DGGE)方法用于肠道菌群多样性分析的各种条件进行了优化,建立了分析人和动物粪便菌群多样性的DGGE方法。2对引物的粪便DGGE结果都表明,珠磨法和冻融研磨法对细菌的裂解效果优于酶法;P3GCf、P2r引物的条带数明显多于U968GCf、L1401r引物;珠磨法PCRDGGE对普通拟杆菌、青春双歧杆菌和粪肠球菌的检测限分别为(6.4±0.1)×102、(6.1±0.7)×103和(7.2±0.2)×105个细菌,珠磨法对这3种细菌的检测限均低于酶法。结果表明,珠磨法和P3GCf、P2r引物更适宜用于粪便菌群多样性DGGE分析。 相似文献
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Abigail S. Bathrick Sarah Norsworthy Dane T. Plaza Mallory N. McCormick Donia Slack Robert S. Ramotowski 《Journal of forensic sciences》2022,67(1):149-160
Forensic examiners must determine whether both latent fingerprint development and DNA profiling can be performed on the same area of an evidence item and, if only one is possible, which examination offers the best chance for identification. Latent fingerprints can be enhanced by targeting different components of fingerprint residues with sequential chemical treatments. This study investigated the effects of single-reagent and sequential latent fingerprint development processes on downstream DNA analysis to determine the point at which latent fingerprint development should be stopped to allow for DNA recovery. Latent fingerprints deposited on copy paper by one donor were developed using three sequential processes: 1,8-diazafluoren-9-one (DFO) → ninhydrin → physical developer (PD); 1,2-indanedione-zinc (IND-Zn) → ninhydrin → PD; and IND-Zn → ninhydrin → Oil Red O (ORO) → PD. Samples were examined after the addition of each chemical treatment. DNA was collected with cotton swabs, extracted, quantified, and amplified. DNA yields, peak heights, number of alleles obtained, and percentage of DNA profiles eligible for CODIS upload were examined. DNA profiles were obtained with varying degrees of success, depending on the number and type of treatments used for latent fingerprint development. The treatments that were found to be the least harmful to downstream DNA analysis were IND-Zn and IND-Zn/laser, and the most detrimental treatments were DFO, DFO/laser, and PD. In general, as the number of treatments increase, the opportunities for DNA loss or damage also increase, and it is preferable to use fewer treatments when developing latent fingerprints prior to downstream DNA processing. 相似文献
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Human chimerism is the presence of ≥ 2 cell populations in one person that contain genetic material from more than one zygote. Chimerism may be either acquired by transfusion or transplantation of donor cells, or congenital arising from embryo fusion or dizygotic twin-twin transfusion. We encountered a 4-year-old boy with developmental hip dysplasia whose preoperative (serologic) blood group was AB, but whose red cell agglutination was atypical ("mixed field") and caused us to study the patient's parents' ABO blood groups. Parental blood groups (AB and O) suggested possible nonparentage. An alternative explanation of the findings was that the child was chimeric or mosaic. Molecular cloning and genotyping of his ABO locus in leukocytes revealed two heterozygous genotypes: A102/O01 and B101/O01. Other loci, each of which possessed three distinct alleles, unambiguously showed transmission of two alleles from either the child's mother (e.g., HLA-A) or two alleles from the child's father (e.g., D8S1179). Findings indicate that the child is a tetragametic chimera. 相似文献
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In this study, we describe a forensic case dealing with the identification of the source of the processed ivory object by DNA analysis. Two pieces of Lord Krishna's idols from a shop were confiscated by an investigating agency of the Indian government and forwarded to us to identify the source of its origin. We succeeded in isolating DNA from both processed ivory idols by using the phenol/chloroform DNA extraction method. The extracted DNA was subjected to PCR amplification using an elephant-specific mitochondrial DNA (mtDNA) D-loop marker. DNA sequence analysis of the amplified fragment of mtDNA D-loop region confirmed that the idols were consistent with Asian elephant with 99% similarity. 相似文献
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Many different molecular typing methods have been reported to complement routine serological ABO blood typing in forensics. However, these ABO genotyping methods are often time-consuming and call for an initial DNA isolation step that requires the use of expensive kits or reagents. We report here a rapid direct ABO genotyping method that eliminates the need for DNA extraction from fresh blood, hair, and body fluid stains before PCR. Using a fast PCR instrument and an optimized polymerase, the genotyping method-which employs a multiplex allele-specific primer set for the simultaneous detection of three single-nucleotide polymorphism (SNP) sites (nucleotides 261, 526, and 803)-identifies A, B, O01/O02, O03, and cis-AB01 alleles in around 70 min from sample collection to electropherogram. Not only will this ABO genotyping method be efficiently used in forensic practice for rapid screening of samples before full-blown multilocus short tandem repeat profiling, but it will also demonstrate an example of rapid direct genotyping of SNPs that offers the advantages of time- and cost-efficiency, convenience, and reduced contamination during DNA analysis. 相似文献
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目的比较甲醛固定石蜡包埋尸检组织中三种提取DNA的方法对DNA质量的影响,寻找一种操作简便、污染较少、经济实用的石蜡包埋组织中提取DNA的方法。方法选取经甲醛固定石蜡包埋的心肌组织20例,分别以二甲苯脱蜡-酚氯仿法、改良TES水浴脱蜡-酚氯仿法、试剂盒法提取DNA,进行电泳分析、紫外分光光度计测定A260/A280值及PCR扩增。结果改良TES水浴脱蜡-酚氯仿法抽提DNA法、二甲苯脱蜡-酚氯仿法分别与试剂盒法所提取DNA的A260/A280值相比较,均有显著性意义(P〈0.01)。二甲苯脱蜡-酚氯仿法、改良TES水浴脱蜡-酚氯仿法所提取DNA的A260/A280值相比较,无显著性意义(P〉0.05)。以改良TES水浴脱蜡-酚氯仿法所得DNA为模板,扩增的目的条带亮度与阳性对照相当。结论结果证实改良TES水浴脱蜡-酚氯仿法简便有效,所用试剂价格低廉,是一种经济实用的石蜡包埋组织DNA提取方法。 相似文献