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1.
This study aimed at the indentification of the species and genotypes of the genus Crataegus in Syria and determination of the genetic relationships among them based on the analysis of genomic and chloroplast DNA (cpDNA)
using ISSRs and CAPS techniques. Morphological characterization carried out on 49 Crataegus samples collected from different geographical regions of Syria revealed four Crataegus species: momogyna, C. sinaica, C. aronia and C. azarolus. In the dendrogram constructed for those samples based on ISSRs (20 primers), all samples that belong to C. monogyna were clustered in one cluster. Samples of the other three species were overlaped in another cluster. Two samples of these
were the most distant from all other samples in the dendrogram and were suggested to represent hybrid species or subspecies.
When CAPS technique was applied on four Crataegus samples that represent the four suggested species using 22 cpDNA regions and 90 endonucleases, no polymorphism was detected
neither in amplification products sizes nor in restriction profiles. The inability of detection of variation in cpDNA among
species suggested can be attributed to the low level of evolution of the cpDNA in the genus, and to the possibility that some
of these species are either subspecies or hybrids since the cpDNA is inherited through one parent only. 相似文献
2.
Early integration of research education into medical curricula is crucial for evidence-based practice. Yet, many medical students are graduating with no research experience due to the lack of such integration in their medical school programs. The purpose of this study was to explore the impact of a peer-organized, extra-curricular research methodology course on the attitudes of medical students towards research and future academic careers. Twenty one medical students who participated in a peer-organized research course were enrolled in three focus group discussions to explore their experiences, perceptions and attitudes towards research after the course. Discussions were conducted using a semi-structured interview guide, and were transcribed and thematically analyzed for major and minor themes identification. Our findings indicate that students’ perceptions of research changed after the course from being difficult initially to becoming possible. Participants felt that their research skills and critical thinking were enhanced and that they would develop research proposals and abstracts successfully. Students praised the peer-assisted teaching approach as being successful in enhancing the learning environment and filling the curricular gap. In conclusion, peer-organized extra-curricular research courses may be a useful option to promote research interest and skills of medical students when gaps in research education in medical curricula exist. 相似文献
3.
Idriss Bennacef Cristian A. Salinas Thomas A. Bonasera Roger N. Gunn Hélène Audrain Steen Jakobsen Nabeel Nabulsi David Weinzimmer Richard E. Carson Yiyun Huang Ian Holmes Fabrizio Micheli Christian Heidbreder Gabriella Gentile Tino Rossi Marc Laruelle 《Bioorganic & medicinal chemistry letters》2009,19(17):5056-5059
Compound 1 is a potent and selective antagonist of the dopamine D3 receptor. With the aim of developing a carbon-11 labeled ligand for the dopamine D3 receptor, 1 was selected as a potential PET probe. [11C]1 was obtained by palladium catalyzed cross coupling using [11C]cyanide and 4 with a specific activity of 55.5 ± 25.9 GBq/μmol (1.5 ± 0.7 Ci/μmol). [11C]1 was tested in porcine and non-human primate models to assess its potential as a radioligand for PET imaging of the dopamine D3 receptor. We conclude that in both species and despite appropriate in vitro properties, [11C]1 does not show any specific signal for the dopamine D3 receptor. 相似文献
4.
Date palm (Phoenix dactylifera L.) is one of the most important domesticated fruit trees in the Near East and North African countries. This tree has been,
for several decades, in serious threat of being completely destroyed by the “Bayoud” disease caused by Fusarium oxysporum f. sp. albedinis. In this study, 18 Syrian date palm cultivars and four male trees were analyzed according to the identity of mitochondrial
plasmid-like DNAs. A PCR strategy that employs plasmid-like DNAs-specific primer pair was used. These primers amplify a product
of either 373-bp or 265-bp that corresponds to the S- (Bayoud-susceptible) or the R-plasmid (Bayoud-resistant), respectively. Generated data revealed that only six cultivars (“Medjool”, “Ashrasi”, “Gish Rabi”,
“Khineze”, and yellow- and red-“Kabkab”) have the S-plasmid, suggesting their susceptibility to the fusariosis, while the remaining 12 cultivars and the four male trees contain
the R-plasmid, suggesting their resistance to the fusariosis. The PCR process applied here has been proved efficient for the rapid
screening for the presence of the S and R DNAs in Syrian date palm. PCR markers developed in this study could be useful for the screening of date palm lines growing
in the field. The availability of such diagnostic tool for plasmid characterization in date palm would also be of great importance
in establishing propagation and breeding programs of date palm in Syria. 相似文献
5.
This study aimed at the indentification of the species and genotypes of the genus Crataegus in Syria and determination of the genetic relationships among them based on the analysis of genomic and chloroplast DNA (cpDNA) using ISSRs and CAPS techniques. Morphological characterization carried out on 49 Crataegus samples collected from different geographical regions of Syria revealed four Crataegus species: C. monogyna, C. sinaica, C. aronia and C. azarolus. In the dendrogram constructed for those samples based on ISSRs (20 primers), all samples that belong to C. monogyna were clustered in one cluster. Samples of the other three species were overlaped in another cluster. Two samples of these were the most distant from all other samples in the dendrogram and were suggested to represent hybrid species or subspecies. When CAPS technique was applied on four Crataegus samples that represent the four suggested species using 22 cpDNA regions and 90 endonucleases, no polymorphism was detected neither in amplification products sizes nor in restriction profiles. The inability of detection of variation in cpDNA among species suggested can be attributed to the low level of evolution of the cpDNA in the genus, and to the possibility that some of these species are either subspecies or hybrids since the cpDNA is inherited through one parent only. 相似文献
6.
7.
Shoot tips and single node explants of two rootstocks (R.99 and 3309) and two varieties (‘Helwani’ and ‘Cabernet Franc’) of
grapevine cultured on DSD1 media for a period of 60 days, were irradiated with 0, 2, 5 and 7 Gy doses of gamma irradiation.
Shoot length of ‘Helwani’ and ‘Cabernet Franc’ was increased by 7 Gy irradiation. The 5 Gy dose increased the number of roots
in plants of the two rootstocks and ‘Helwani’. Root length of ‘Helwani’ and ‘Cabernet Franc’ at the 2 and 7 Gy doses were
significantly higher than those of the non-irradiated control. A similar effect was noticed on R.99 rootstock subjected to
5 Gy. Five Gy also increased the dry weight of the R.99 rootstock, whereas 2 and 7 Gy had a similar effect on ‘Helwani’ and
‘Cabernet Franc’. Number of leaves of plants exposed to 5 and 7 Gy was increased when compared with the non-irradiated control.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
8.
[11C]Glycylsarcosine (Gly-Sar) was synthesized as a potential radiotracer to investigate the localization and in vivo function of the peptide transporter PepT2 in mouse kidney. Its C-11 labeled diketopiperazine derivative, [11C]cyclo(Gly-Sar) [1-methylpiperazine-2,5-dione], was also evaluated as a potential tracer. [11C]Gly-Sar exhibited rapid initial uptake into kidneys with slow clearance from the medulla, consistent with uptake and retention of the radiotracer through the actions of PepT2. In contrast, the corresponding cyclized dipeptide [11C]cyclo(Gly-Sar) showed rapid clearance and accumulation only in the renal pelvis region. Involvement of PepT2 in reabsorption and delayed clearance of [11C]Gly-Sar was confirmed using the PepT2 knockout mouse, where rapid renal elimination of [11C]Gly-Sar and the absence of radioactivity in medulla were observed. This study demonstrates using in vivo imaging technique that PepT2 is primarily responsible for renal tubular active reabsorption of Gly-Sar, and provides a new tool for studying tubular peptide reabsorption and clearance. 相似文献
9.
Vazken M. Der Kaloustian Rola Masri Adele Khudr Fayrouz Talj Bisharah Libbus Mona Nabulsi Farid P. Khouri 《Human genetics》1987,75(1):97-97
Summary This is the first report in the literature of siblings affected with Down syndrome; one sibling had a nondisjunction of chromosome 21 and the other a (21q;21q) translocation. 相似文献
10.
Date palm (Phoenix dactylifera L.) is one of the most important domesticated fruit trees in the Near East and North African countries. This tree has been, for several decades, in serious threat of being completely destroyed by the "Bayoud" disease caused by Fusarium oxysporum f. sp. albedinis. In this study, 18 Syrian date palm cultivars and four male trees were analyzed according to the identity of mitochondrial plasmid-like DNAs. A PCR strategy that employs plasmid-like DNAs-specific primer pair was used. These primers amplify a product of either 373-bp or 265-bp that corresponds to the S-(Bayoud-susceptible) or the R-plasmid (Bayoud-resistant), respectively. Generated data revealed that only six cultivars ('Medjool', 'Ashrasi', 'Gish Rabi', 'Khineze', and yellow- and red-'Kabkab') have the S-plasmid, suggesting their susceptibility to the fusariosis, while the remaining 12 cultivars and the four male trees contain the R-plasmid, suggesting their resistance to the fusariosis. The PCR process applied here has been proved efficient for the rapid screening for the presence of the S and R DNAs in Syrian date palm. PCR markers developed in this study could be useful for the screening of date palm lines growing in the field. The availability of such diagnostic tool for plasmid characterization in date palm would also be of great importance in establishing propagation and breeding programs of date palm in Syria. 相似文献