| 1. |
- Cao, Hui, et al.
(författare)
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Identification of switching mechanism in molecular junctions by inelastic electron tunneling spectroscopy
- 2008
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 112:29, s. 11018-11022
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Tidskriftsartikel (refereegranskat)abstract
- We present first-principles studies on electron transport properties of Pd-dithiolated oligoaniline-Pd molecular junctions. It is to demonstrate the possibility of using inelastic electron tunneling spectroscopy (IETS) to identify the switching mechanism in the molecular junction. Calculations have successfully reproduced the experimentally observed conductance switching behavior and the corresponding inelastic electron tunneling spectra. It is shown that the conductance switching is induced by conformation changes of the intercalated dithiolated oligoaniline in the junctions rather than oxidation/reduction as proposed earlier. Among three possible isomers, the low and high conductance states are related to two symmetrical structures. The possible involvement of asymmetric structure is discussed. It is revealed that chemical bonds between the terminal S atom and Pd electrodes are quite weak with relatively long bond distances.
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| 2. |
- Cao, Hui, et al.
(författare)
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Temperature-dependent statistical behavior of single molecular conductance in aqueous solution
- 2008
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Ingår i: Journal of the American Chemical Society. - : American Chemical Society (ACS). - 0002-7863 .- 1520-5126. ; 130:21, s. 6674-
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Tidskriftsartikel (refereegranskat)abstract
- We have combined molecular dynamics simulations with first principles calculations to study electron 4 transport in a single molecule of perylene tetracarboxylic diimide (PTCDI) sandwiched between two gold electrodes with an aqueous electrolyte. This combination has for the first time allowed one to reveal statistical behavior of molecular conductance in solution at different temperatures and to produce conductance histograms that can be directly compared with experiments. Our calculations show that experimentally observed temperature-dependent conductance ran be attributed to the thermal effect on the hydrogen bonding network around the molecule and can be described by the radial distribution of water molecules surrounding the oxygen atom in the PTCDI molecule.
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| 3. |
- Ma, Jun, et al.
(författare)
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Distribution of neuropeptide Y Leu7Pro polymorphism in patients with type 1 diabetes and diabetic nephropathy among Swedish and American populations.
- 2007
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Ingår i: Eur J Endocrinol. - 1479-683X. ; 157:5, s. 641-5
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: The distribution of Leu7Pro polymorphism in the neuropeptide Y gene shows a geographical north to south gradient of decreasing frequency, suggesting that it may be a population-specific causal variant. This polymorphism is found to be associated with diabetic nephropathy (DN) and coronary heart disease in Finnish women with type 1 diabetes (T1D). The present study aims to evaluate the susceptibility of this polymorphism to the development of DN in two different populations. DESIGN: One sample set consists of 174 (females 98 and males 76) Swedish T1D patients with DN and 249 (females 132 and males 117) patients without DN. Another sample set includes 597 (females 356 and males 241) American T1D patients without DN and 577 (females 264 and males 313) patients with DN, who were descents of European Caucasians and were from the Genetics of Kidneys in Diabetes (GoKinD) Study. METHODS: Genotyping of Leu7Pro polymorphism was performed by dynamic allele-specific hybridization. RESULTS: The C allele frequencies of Leu7Pro polymorphism in T1D patients between Swedish and American GoKinD populations were significantly different (6.3 vs 4.0%; P=0.006). Particularly, the C allele frequency in Swedish female T1D patients with DN was significantly higher in comparison with T1D patients without DN (10.2 vs 4.2%; P=0.011, OR=2.614, 95% confidence intervals: 1.249-5.467). No significant association of this polymorphism with DN was observed in Swedish male T1D patients and the patients from GoKinD. CONCLUSIONS: The present study provides further evidence that Leu7Pro polymorphism confers the susceptibility to the development of DN in Swedish female T1D patients.
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| 4. |
- Ma, Jun, et al.
(författare)
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Genetic association analysis of the adiponectin polymorphisms in type 1 diabetes with and without diabetic nephropathy.
- 2007
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Ingår i: J Diabetes Complications. - : Elsevier BV. - 1056-8727. ; 21:1, s. 28-33
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Tidskriftsartikel (refereegranskat)abstract
- OBJECTIVE: Adiponectin [adipocyte C1q and collagen domain containing (ACDC)] is the most abundant adipose-specific protein. It is beneficial in that it improves insulin sensitivity and mitigates vascular damage, in addition to the possibility of it having anti-inflammatory properties. Clinical evidences demonstrate that serum adiponectin concentrations are increased in patients with type 1 diabetes (T1D) as well as in patients with microvascular complications. However, the genetic influence of the ACDC gene in T1D and diabetic microvascular complications is still unclear. The present study aims to evaluate the association of the ACDC genetic variation in T1D and diabetic nephropathy (DN). MATERIALS AND METHODS: Ten single nucleotide polymorphisms (SNPs) of the ACDC gene were genotyped in 432 T1D patients (of which, 196 had DN) and 187 nondiabetic control subjects, who were all Swedish Caucasians, by using dynamic allele specific hybridization. RESULTS: Single-marker association analysis demonstrated that SNPs +45G15G(T/G) and +276(G/T) were strongly associated with T1D [P=.002, OR=1.855 (1.266-2.717) and P=.001, OR=1.694 (1.337-2.147)]. Further analysis for haplotypes of these two SNPs indicated that one of the common haplotype (T_G) was strongly associated with T1D [P<.001, OR=1.769 (1.430-2.188)]. However, there was no significant difference in the allele frequencies of these two SNPs between the groups of T1D patients with nephropathy and the patients without nephropathy. CONCLUSIONS: The present study thus suggests that SNPs +45G15G(T/G) and +276(G/T) in the ACDC gene are associated with T1D but not with DN among Swedish Caucasians.
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| 5. |
- Ma, Jun
(författare)
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Identification of the susceptibility genes in type 1 diabetes and diabetic nephropathy
- 2007
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Genetic susceptibility plays an important role in the pathogenesis of type 1 diabetes (T1D) and diabetic nephropathy (DN). The present study aims to investigate the association between single nucleotide polymorphisms (SNPs) in candidate genes and DN. Three candidate genes, the intercellular adhesion molecule-1 (ICAM-1), adiponectin (AdipoQ) and neuropeptide Y (NPY), have been selected based upon the approaches: i) from the specific chromosomal regions predicted as important for development of DN by the previous genome wide scan and linkage studies; ii) from the main regulatory steps in the pathways participating in development of diabetic micro-vascular complications. The studied subjects include 445 Swedish T1D patients with and without DN and 1282 American T1D patients with and without DN selected from the Genetics of Kidneys in Diabetes (GoKinD) study. Genotyping experiments were performed using dynamic allele specific hybridization (DASH). Pyrosequencing and direct sequencing techniques were used for confirmation experiments. Both ICAM-1 and AdipoQ genes are the strong positional and biological candidates for genetic association study in T1D and DN. We first carried out a genetic association study of the ICAM-1 gene in Swedish subjects and found that SNP rs5498 E469K(A/G) had a high heterozygous index. Frequencies of the allele G in this SNP were decreased gradually from non-diabetic controls, to T1D patients without DN and the patients with DN. Direct sequencing analysis for the subjects with high heterozygous index was performed, but no duplicon in the genomic region around the SNP was found. We further evaluated association between the ICAM-1 genetic polymorphisms and DN with the GoKinD subjects, and found that the allele G in SNP rs5498 E469K(A/G) was significantly associated with the decreased risk susceptibility of DN in female T1D patients. To evaluate the association of AdipoQ genetic polymorphisms with DN in T1D, we have identified 4 binding sites of transcriptional stimulatory protein (SP1) in the AdipoQ putative promoter. The allele G of SNP -11377C/G in the promoter altered the sequence for one of SP1 binding sites. This promoter polymorphism and its common diplotype (haplotypic genotype) constructed with this SNP and -11391G/A are found to be associated with DN in female T1D patients among the GoKinD population. Leu7Pro polymorphism in the NPY gene is found to be associated with DN and coronary heart disease in Finnish women with T1D. We replicated a genetic association study of this polymorphism in both Swedish and GoKinD subjects. The allele C frequency of Leu7Pro polymorphism in Swedish T1D was higher than in the GoKinD population. This polymorphism was found to be significantly associated with DN in Swedish female T1D patients. The present study provides evidence that ICAM-1, AdipoQ and NPY genetic polymorphisms are associated with DN in T1D. Genetic susceptibility of the polymorphisms may be influenced by many factors, including gender specificity and ethnic stratification.
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| 6. |
- Ma, Li-Jun, et al.
(författare)
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Genomic analysis of the basal lineage fungus Rhizopus oryzae reveals a whole-genome duplication.
- 2009
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Ingår i: PLoS genetics. - : Public Library of Science (PLoS). - 1553-7404. ; 5:7, s. e1000549-
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Tidskriftsartikel (refereegranskat)abstract
- Rhizopus oryzae is the primary cause of mucormycosis, an emerging, life-threatening infection characterized by rapid angioinvasive growth with an overall mortality rate that exceeds 50%. As a representative of the paraphyletic basal group of the fungal kingdom called "zygomycetes," R. oryzae is also used as a model to study fungal evolution. Here we report the genome sequence of R. oryzae strain 99-880, isolated from a fatal case of mucormycosis. The highly repetitive 45.3 Mb genome assembly contains abundant transposable elements (TEs), comprising approximately 20% of the genome. We predicted 13,895 protein-coding genes not overlapping TEs, many of which are paralogous gene pairs. The order and genomic arrangement of the duplicated gene pairs and their common phylogenetic origin provide evidence for an ancestral whole-genome duplication (WGD) event. The WGD resulted in the duplication of nearly all subunits of the protein complexes associated with respiratory electron transport chains, the V-ATPase, and the ubiquitin-proteasome systems. The WGD, together with recent gene duplications, resulted in the expansion of multiple gene families related to cell growth and signal transduction, as well as secreted aspartic protease and subtilase protein families, which are known fungal virulence factors. The duplication of the ergosterol biosynthetic pathway, especially the major azole target, lanosterol 14alpha-demethylase (ERG11), could contribute to the variable responses of R. oryzae to different azole drugs, including voriconazole and posaconazole. Expanded families of cell-wall synthesis enzymes, essential for fungal cell integrity but absent in mammalian hosts, reveal potential targets for novel and R. oryzae-specific diagnostic and therapeutic treatments.
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| 7. |
- Ma, Ning, et al.
(författare)
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A 5Mgate/414mW Networked Media SoC in 0.13um CMOS with 720p Multi-Standard Video Decoding
- 2009
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Ingår i: 2009 IEEE ASIAN SOLID-STATE CIRCUITS CONFERENCE (A-SSCC). - : IEEE Solid-State Circuits Society. - 9781424444342 ; , s. 385-388
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Konferensbidrag (refereegranskat)abstract
- A flexible and high performance SoC is developed for networked media applications by integrating two RISC cores, Ethernet network interface and coarse-grained configurable video decoding unit. Real-time 1280x720@25fps MPEG-2/MPEG-4/RealVideo decoding is achieved for on-line video streams. The SoC is fabricated in 0.13um single-poly eight-metal CMOS technology with core size of 6.4mm * 6.4mm. To achieve low power design, flexible power management strategy is implemented for dynamically control of computational capabilities with various workloads. The maximum power consumption is 414mW at 1.2V supply voltage with the corresponding system frequency of 216MHz, when real-time HD (1280x720@25fps) video streams are decoded. When the SoC decodes real-time CIF (352x288@25fps) video streams, it requires 27MHz system frequency and consumes 95mW.
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| 8. |
- Stål, Olle, et al.
(författare)
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Validation of Prognostic Utility of HOXB13:IL17BR and Molecular Grade Index in Early Stage Breast Cancer : in CANCER RESEARCH, vol 69, issue 24, pp 504S-504S
- 2009
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Konferensbidrag (refereegranskat)abstract
- Background. HOXB13:IL17BR (H:I) is a two gene expression index, which has been shown to be an independent prognostic factor in estrogen receptor (ER)-positive lymph node-negative (N0) breast cancer. A molecular grade index (MGI) measures the expression of five proliferation-related genes. An algorithm based on dichotomized H:I and MGI stratifying patients into three risk groups has been shown to be superior to either alone in predicting risk of distant metastasis in ER+/N0 patients. Further validation in larger cohorts is needed to establish its clinical performance. A continuous predictor combining H:I and MGI is desirable for making individualized risk assessment in the clinical setting. Methods. During 1976 through 1990 the Stockholm Breast Cancer Group conducted a randomized clinical trial comparing adjuvant tamoxifen with control in 1780 postmenopausal women considered to be at low risk of recurrence (N0 and tumor size < 3 cm). We measured H:I and MGI using a real time PCR assay in 769 patients from this trial based on sample availability. Correlation of gene expression indices with distant metastasis and death due to breast cancer was evaluated by Kaplan-Meier analysis and Cox proportional hazard regression. Modeling was also used to develop a continuous risk index as a function of both H:I and MGI. Results. Using pre-specified cutoff points and combination algorithm, H:I, MGI and their combination each was significantly associated with both distant metastasis-free survival and breast cancer-specific survival (Table 1). Furthermore, we used the ER+ tamoxifen-treated subset (n=314) to develop a continuous risk model (Breast Cancer Index or BCI) combining both H:I and MGI. The prognostic utility of BCI was then successfully validated in the untreated subset in this trial and three additional previously published cohorts. BCI consistently identified ∼50% patients with a very low 10-year recurrence risk (< 5%). Discussion. This large retrospective analysis of a randomized clinical trial cohort validated the prognostic utility of H:I, MGI, and their combination. With the continuous risk model, this RT-PCR-based assay allows prediction of risk of recurrence at the individual level, which may help tailor personalized treatment strategy.
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| 9. |
- Yasuda, Kazuki, et al.
(författare)
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Variants in KCNQ1 are associated with susceptibility to type 2 diabetes mellitus
- 2008
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1546-1718 .- 1061-4036. ; 40:9, s. 1092-1097
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Tidskriftsartikel (refereegranskat)abstract
- We carried out a multistage genome-wide association study of type 2 diabetes mellitus in Japanese individuals, with a total of 1,612 cases and 1,424 controls and 100,000 SNPs. The most significant association was obtained with SNPs in KCNQ1, and dense mapping within the gene revealed that rs2237892 in intron 15 showed the lowest P value (6.7 x 10(-13), odds ratio (OR) = 1.49). The association of KCNQ1 with type 2 diabetes was replicated in populations of Korean, Chinese and European ancestry as well as in two independent Japanese populations, and meta-analysis with a total of 19,930 individuals (9,569 cases and 10,361 controls) yielded a P value of 1.7 x 10(-42) (OR = 1.40; 95% CI = 1.34-1.47) for rs2237892. Among control subjects, the risk allele of this polymorphism was associated with impairment of insulin secretion according to the homeostasis model assessment of beta-cell function or the corrected insulin response. Our data thus implicate KCNQ1 as a diabetes susceptibility gene in groups of different ancestries.
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