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排序方式: 共有172条查询结果,搜索用时 15 毫秒
1.
S. M. Ghaffari 《Plant Systematics and Evolution》1986,153(3-4):199-204
Meiosis and mitosis are described in cultivatedCrocus sativus of Iran. This indicates that this species is an autotriploid and sterile. Karyotype analysis, rare inversions, laggard chromosomes and distribution of chromosomes in the first anaphase are described, and the reasons for its sterility are given. 相似文献
2.
Cloning and sequence analysis of channel catfish heavy chain cDNA indicate phylogenetic diversity within the IgM immunoglobulin family 总被引:6,自引:0,他引:6
Catfish cDNA libraries were constructed using the poly(A+) RNA obtained from in vitro stimulated catfish leukocytes. Antigenic analysis with different antisera to catfish Ig resulted in the definition of cDNA clones encoding the catfish H chain. Sequence analysis confirmed that the catfish H chain was definitively identified, based on its similarities with chicken and mouse mu chains. Two clones were each shown to encode part of the CH2 domain, the complete CH3 and CH4 domains, the C-terminus, and a 184-bp 3' untranslated region before the poly(A+) tail. The conservation of domain size and structure is clearly evident. The two cysteines forming the intradomain disulfide bridge, as well as the tryptophans located within each domain, are absolutely conserved. There are four carbohydrate acceptor sites in the catfish H chain, only one of which is phylogenetically conserved. Of the six sequenced H chain clones, one was found to differ in a single base in the CH3, which results in the loss of a carbohydrate acceptor site. Whether this difference indicates isotypic variation between closely related genes or somatic mutation is unresolved. Amino acid sequence comparisons indicate that there is a approximately 24% similarity when the catfish H chain is aligned with mouse mu chains. This is considerably less than the approximately 40% amino acid conservation found between the chicken and mouse mu chain. The amino acid sequence of the catfish H chain is most conserved in the C-terminus (approximately 30%) and the CH4 (approximately 26%); there is less conservation in the CH3 (approximately 20%) when comparisons are made with mouse mu chain. The CH3 domain of the catfish H chain also has different hydropathy properties, when compared with the CH3 domain of the higher vertebrate mu chains. Finally, the sequence of the catfish H chain indicates an unusual arrangement of the cysteines that likely participate in intersubunit and inter-H chain disulfide linkages. The disulfide linkage of these cysteines during Ig polymerization may account for the unusual covalent architecture associated with the catfish tetramer. 相似文献
3.
Anticancer potential of Ferula assa-foetida and its constituents,a powerful plant for cancer therapy
Mohammad Amin Ghaffari Sirizi Jalil Alizadeh Ghalenoei Mohammad Allahtavakoli Hasan Forouzanfar Seyyed Majid Bagheri 《World journal of biological chemistry》2023,14(2):28-39
Cancer is one of the main challenges of the health system around the world. This disease is increasing in developing countries and imposes heavy costs on patients and governments. On the other hand, despite various drugs, the death rate among cancer patients is still high and the current treatments have many harmful effects. In the traditional medicine of different countries, there are many medicinal plants that can be effective in the treatment of cancer. Ferula plants are traditionally used as spices and food or for medicinal purposes. Ferula assa-foetida is one of the famous plants of this genus, which has been used for the treatment of various diseases since ancient times. Among the main compounds of this plant, we can mention monoterpenes, sulfide compounds and polyphenols, which can show different therapeutic effects. This article has been compiled with the aim of collecting evidence and articles related to the anti-cancer effects of extracts, derived compounds, essential oils and nanoparticles containing Ferula assa-foetida. This review article was prepared by searching the terms Ferula assa-foetida and cancer, and relevant information was collected through searching electronic databases such as ISI Web of Knowledge, PubMed, and Google Scholar. Fort unately, the results of this review showed that relatively comprehensive studies have been conducted in this field and shown that Ferula assa-foetida can be very promising in the treatment of cancer. 相似文献
4.
Mohyeddin Mandana Bonab Kamran Alimoghaddam Fatemeh Talebian Syed Hamid Ghaffari Ardeshir Ghavamzadeh Behrouz Nikbin 《BMC cell biology》2006,7(1):14-7
Background
A hot new topic in medical treatment is the use of mesenchymal stem cells (MSC) in therapy. The low frequency of this subpopulation of stem cells in bone marrow (BM) necessitates their in vitro expansion prior to clinical use. We evaluated the effect of long term culture on the senescence of these cells. 相似文献5.
Saremi Leila Shafizadeh Marziyeh Esmaeilzadeh Emran Ghaffari Mohammad Ebrahim Mahdavi Mohammad hosein Amid Reza Kadkhodazadeh Mahdi 《Molecular biology reports》2021,48(3):2285-2290
Molecular Biology Reports - Peri-implantitis (PI) is a multifactorial condition caused by the interactions of pathogens and the host immune response. Previous studies have demonstrated a... 相似文献
6.
M. Ghasemi A. Ghaffari H. SadAbadi H. Golbayani 《Computer methods in biomechanics and biomedical engineering》2013,16(6):857-864
Hypothesis/objective: Prolonged QT interval is an index of propensity for dangerous ventricular tachyarrhythmias. The aim of this article is to establish an automatic algorithm for QT interval measurement. Method: The proposed method is based on the continuous wavelet transform. In this method, the concepts of the rescaled wavelet coefficients and dominant scales of the electrocardiogram (ECG) components are used to perform detection of ECG characteristic points. A new concept of rescaled maximum energy density is introduced so as to perform the estimation of the QT interval. Results and conclusion: We have applied the algorithm to the PTB database of the Physiobank?Physionet in lead II. Then, the results were evaluated using pertinent reference QT. The criterion used for evaluation of the method's performance is the root mean square (RMS) error. The method approached the RMS error of 27.89 ms for 549 subjects. The proposed method is fast, simple and is applicable to a wide range of ECG cardio cycle morphologies. 相似文献
7.
Rashin Ghaffari Ethalinda K. S. Cannon Lisa B. Kanizay Carolyn J. Lawrence R. Kelly Dawe 《Chromosoma》2013,122(1-2):67-75
Knobs are conspicuous heterochromatic regions found on the chromosomes of maize and its relatives. The number, locations, and sizes of knobs vary dramatically, with most lines containing between four and eight knobs in mid-arm positions. Prior data suggest that some knobs may reduce recombination. However, comprehensive tests have not been carried out, primarily because most knobs have not been placed on the genetic map. We used fluorescent in situ hybridization and two recombinant inbred populations to map seven knobs and to accurately place three knobs from the B73 inbred on the genomic sequence assembly. The data show that knobs lie in gene-dense regions of the maize genome. Comparisons to 23 other recombinant inbred populations segregating for knobs at the same sites confirm that large knobs can locally reduce crossing over by as much as twofold on a cM/Mb scale. These effects do not extend beyond regions ~10 cM to either side of knobs and do not appear to affect linkage disequilibrium among genes within and near knob repeat regions of the B73 RefGen_v2 assembly. 相似文献
8.
Two karyotypic variants were recognized in populations of Acanthophyllum laxiusculum Schiman-Czeika. Variant A had 2N = 30 and variant B showed the presence of 0 to 3 B-chromosomes in addition to 2N = 30 chromosomes. Analysis of chromosome behaviour at meiosis showed that the presence of B-chromosomes increases chiasma frequency in A-chromosomes; this effect was higher for plants with odd numbers of B-chromosomes compared with plants with even numbers of B-chromosomes. Comparisons of variants A and B, suggests that B-chromosomes have an effect pollen stainability and seed production. It seems that the presence of B-chromosomes may increase pollen stainability and seed production in variant B. 相似文献
9.
10.
Guozhi Tang Denis J. Kertesz Minmin Yang Xianfeng Lin Zhanguo Wang Wentao Li Zongxing Qiu Junli Chen Jianghua Mei Li Chen Taraneh Mirzadegan Seth F. Harris Armando G. Villaseñor Jennifer Fretland William L. Fitch Julie Qi Hang Gabrielle Heilek Klaus Klumpp 《Bioorganic & medicinal chemistry letters》2010,20(20):6020-6023