| 1. |
- Ben Slimane, Slimane, et al.
(författare)
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Delay Optimization in Cooperative Relaying with Cyclic Delay Diversity
- 2008
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Ingår i: 2008 IEEE International Conference On Communications, Proceedings. - 9781424420742 ; , s. 3553-3557
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Konferensbidrag (refereegranskat)abstract
- Cooperative relaying has recently been recognized as an alternative to MIMO in a typical multi cellular environment Inserting random delays at the non-regenerative fixed relays, further improve the system performance. However, random delay results in limited performance gain from multipath diversity. In this paper, two promising delay optimization schemes are introduced for a multi cellular OFDM system with cooperative relaying with stationary multiple users and fixed relays. Both of the schemes basically aim to take the most advantages of the potential frequency selectivity by inserting pre-determined delays at the relays, in order to further improve the system performance (coverage and throughput). Evaluation results for different multipath fading environments show that the system performance with delay optimization increases tremendously compared with the case of random delay.
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| 2. |
- Ben Slimane, Slimane, et al.
(författare)
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Delay Optimization in Cooperative Relaying with Cyclic Delay Diversity
- 2008
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Ingår i: EURASIP Journal on Advances in Signal Processing. - : Springer Science and Business Media LLC. - 1687-6172 .- 1687-6180. ; , s. 736818-
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Tidskriftsartikel (refereegranskat)abstract
- Cooperative relaying has recently been recognized as an alternative to MIMO in a typical multicellularenvironment. Inserting random delays at the nonregenerative fixed relays further improve the system performance.However, random delays result in limited performance gain from multipath diversity. In this paper, two promisingdelay optimization schemes are introduced for a multicellular OFDM system with cooperative relaying withstationary multiple users and fixed relays. Both of the schemes basically aim to take the most advantages ofthe potential frequency selectivity by inserting predetermined delays at the relays, in order to further improve thesystem performance (coverage and throughput). Evaluation results for different multipath fading environments showthat the system performance with delay optimization increases tremendously compared with the case of randomdelay.
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| 3. |
- Ederth, Thomas, et al.
(författare)
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Interactions of Zoospores of Ulva linza with Arginine-Rich Oligopeptide Monolayers
- 2009
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Ingår i: Langmuir. - : American Chemical Society (ACS). - 0743-7463 .- 1520-5827. ; 25:16, s. 9375-9383
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Tidskriftsartikel (refereegranskat)abstract
- We recently reported oil the strong interactions of zoospores of the green alga, Ulva linza with all arginine-rich oligopeptide self-assembled monolayer (SAM) [Biofouling 2008, 24, 303-312], where the arginine-rich peptide induced not only high spore settlement, but also a form of abnormal settlement, or "pseudo-settlement", whereby it proportion of spores do not go through the normal process of surface exploration, adhesive exocytosis, and loss of flagella. Further. it was demonstrated that both the total number of settled spores and the fraction of pseudosettled spores were related to the surface density of the arginine-rich peptide. Here we present a further investigation of the interactions of zoospores of ulva with a set of oligomeric, de nom designed, arginine-rich peptides, specifically aimed to test the effect of peptide primary structure on the interaction. Via variations in the peptide length and by permutations in the amino acid sequences, we gain further insight into the spore-surface interactions. The interpretation of the biological assays is supported by physicochemical characterization of the SAMs using infrared spectroscopy, ellipsometry, and contact angle measurement. Results confirm the importance of arginine residues for the anomalous pseudosettlement, and we found that settlement is modulated by variations in both the total length and peptide primary structure. To elucidate the Causes of the anomalous settlement and the possible relation to peptide-membrane interactions, we also compared the settlement of the "naked" zoospores of Ulva(which present it lipoprotein membrane to the exterior without a discrete polysaccharide cell wall), with the settlement of diatoms (unicellular algae that are surrounded by it silica cell wall), onto the peptide SAMs. Cationic SAMs do not notably affect settlement (attachment), adhesion strength, or viability of diatom cells, Suggesting that the effect of the peptides on zoospores of Ulva is mediated via specific peptide-membrane interactions.
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| 4. |
- Li, Longkun, et al.
(författare)
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Changes in T-type calcium channel and its subtypes in overactive detrusor of the rats with partial bladder outflow obstruction
- 2007
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Ingår i: Neurourology and Urodynamics. - : Wiley. - 0733-2467 .- 1520-6777. ; 26:6, s. 870-878
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Tidskriftsartikel (refereegranskat)abstract
- AimsTo investigate the activity of the T-type calcium channel (TCC) and the expression of its subtypes in overactive detrusor (OD) myocytes in rats after partial bladder outflow obstruction (PBOO).MethodsThirteen male Wistar rats with OD after PBOO (OD group) and eight sham-operated rats (control group) were studied. The two groups were compared regarding the expression of TCC subtype genes by reverse transcription-polymerase chain reaction (RT-PCR) and the TCC kinetics and cell action potential by whole-cell patch-clamp.ResultsThe time course and density of the current were significantly higher in the OD cells than those in the control detrusor. Whole-cell patch-clamp analysis showed that the activation of TCCs in detrusor myocytes in the OD group was faster than the control group, but inactivation was almost the same in both groups, suggesting a significant enhancement of the Ca2+ window current in the OD group. Patch-clamp recording of action potentials in the OD cells indicated an increase in excitability and a decrease in the repolarization interval. RT-PCR assay showed an abnormal expression of 1G subtype in the OD cells.ConclusionsTCCs could be one of the crucial factors for the abnormal excitation in OD cells. The development of OD after PBOO presumably relates to the increase in TCC current in the bladder cells, the enhancement of the Ca2+ window current for Ca2+ inflow, the prolongation of the intracellular calcium oscillations, and the acceleration of the cell depolarization.
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| 5. |
- Li, longkun, et al.
(författare)
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Transurethral endoscopy technique with a ureteroscope for diagnosis and management of seminal tracts disorders: a new approach
- 2008
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Ingår i: Journal of endourology. - : Mary Ann Liebert Inc. - 0892-7790 .- 1557-900X. ; 22:4, s. 719-724
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Tidskriftsartikel (refereegranskat)abstract
- Purpose: To apply a transurethral endoscopic technique for examining and managing suspicious distal seminal tracts disorders with a ureteroscope. Patients and Methods: Sixteen patients with distal seminal tracts disorders underwent transurethral endoscopy through the distal seminal tracts using a semirigid ureteroscope. Of the 16 patients, 6 had suspected hemospermia, 4 spermatocele, and 6 male infertility. Results: The ejaculatory duct, seminal vesicle, and ampulla of the vas deferens were observed under direct vision with the ureteroscope. The vas deferens was investigated by cannulation with a guidewire or an epidural anesthesia catheter. Four patients received a diagnosis of spermatocele, four seminal vesiculitis, and three vas deferens obstruction. All patients received appropriate treatment. The remaining five patients had no anatomic disorders. All patients received careful postoperative observation and treatment, and were monitored for at least 3 months. Three patients had postoperative discomfort in the perineal region. There were no further complications. Conclusions: This new technique with the ureteroscope enables diagnosis and management of distal seminal tracts disorders through the normal anatomic tract. This endoscopic technique can be performed easily with minimal complications.
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| 6. |
- Li, Weiwei, et al.
(författare)
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Benzothiadiazole-Based Linear and Star Molecules : Design, Synthesis, and Their Application in Bulk Heterojunction Organic Solar Cells
- 2009
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Ingår i: CHEMISTRY OF MATERIALS. - : American Chemical Society (ACS). - 0897-4756 .- 1520-5002. ; 21:21, s. 5327-5334
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Tidskriftsartikel (refereegranskat)abstract
- Star molecules have many advantages, such as monodispersity, excellent solubility, and vast structures with different functional groups. A set of four-arm star molecules with benzothiadiazole as the core, oligothiophene its the arm, and triphenylamine its the end group and their linear counterparts were designed and synthesized Organic solar cells (OSCs) fabricated with these star molecules and [6,6]-phenyl C-71 butyric acid methyl ester (PC71BM) by spin-coating from solution demonstrate similar short circuit current density (J(sc)) and fill factor (FF) but larger open circuit voltage (V-oc) in comparison With solar cells fabricated with corresponding linear molecules and PC71BM A power conversion efficiency (PCE) of 18%, with J(sc) = 4.9 mA/cm(2), V-oc = 0 92 V, and FF = 0 41 was achieved with one of these star molecules
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| 7. |
- Sun, Jie, et al.
(författare)
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Scanning electron microscopy observation of in-device InAs/AlAs quantum dots by selective etching of capping layers
- 2007
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Ingår i: Modern Physics Letters B. - 0217-9849. ; 21:14, s. 859-866
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Tidskriftsartikel (refereegranskat)abstract
- Self-assembled InAs/AlAs quantum dots embedded in a resonant tunneling diode device structure are grown by molecular beam epitaxy. Through the selective etching in a C6H8O7 center dot H2O-K3C6H5O7 center dot H2O-H2O2 buffer solution, 310 nm GaAs capping layers are removed and the InAs/AlAs quantum dots are observed by field-emission scanning electron microscopy. It is shown that as-fabricated quantum dots have a diameter of several tens of nanometers and a density of 10(10) cm(-2) order. The images taken by this means are comparable or slightly better than those of transmission electron microscopy. The undercut of the InAs/AlAs layer near the edges of mesas is detected and that verifies the reliability of the quantum dot images. The inhomogeneous oxidation of the upper AlAs barrier in H2O2 is also observed. By comparing the morphologies of the mesa edge adjacent regions and the rest areas of the sample, it is concluded that the physicochemical reaction introduced in this letter is diffusion limited.
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| 8. |
- Xu, Ning, et al.
(författare)
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Adenovirus virus-associated RNAII-derived small RNAs are efficiently incorporated into the RNA-induced silencing complex and associate with polyribosomes
- 2007
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Ingår i: Journal of Virology. - 0022-538X .- 1098-5514. ; 81:19, s. 10540-10549
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Tidskriftsartikel (refereegranskat)abstract
- Adenovirus type 5 encodes two highly structured short RNAs, the virus-associated (VA) RNAI and RNAII. Both are processed by Dicer into small RNAs that are incorporated into the RNA-induced silencing complex (RISC). We show here, by cloning of small RNAs, that approximately 80% of Ago2-containing RISC immunopurified from late-infected cells is associated with VA RNA-derived small RNAs (mivaRNAs). Most surprisingly, VA RNAII, which is expressed at 20-fold lower levels compared to that of VA RNAI, appears to be the preferred substrate for Dicer and accounts for approximately 60% of all small RNAs in RISC. The mivaRNAs are derived from the 3' strand of the terminal stems of the VA RNAs, with the major fraction of VA RNAII starting at position 138. The small RNAs derived from VA RNAI were more heterogeneous in size, with the two predominant small RNAs starting at positions 137 and 138. Collectively, our results suggest that the mivaRNAs are efficiently used for RISC assembly in late-infected cells. Potentially, they function as miRNAs, regulating translation of cellular mRNAs. In support of this hypothesis, we detected a fraction of the VA RNAII-derived mivaRNAs on polyribosomes.
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| 9. |
- Zhou, Yan, et al.
(författare)
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Capacitance Effect on Microwave Power Spectra of Spin-Torque Oscillator With Thermal Noise
- 2009
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Ingår i: IEEE transactions on magnetics. - 0018-9464 .- 1941-0069. ; 45, s. 2773-2776
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Tidskriftsartikel (refereegranskat)abstract
- A macro-spin simulation has been carried out to study the thermal stability of a spin-torque oscillator (STO) connected in parallel with a capacitance. To study the impact of realistic thermal fluctuation on an STO, a stochastic magnetic field vector is added into the Landau-Lifshitz-Gilbert-Slonczewski (LLGS) equation. From the numerical solution, it is found that the addition of capacitance positively influences the thermal stability of the system, and can improve the quality factor of the microwave power spectrum even in the presence of thermal fluctuation. The results of I-V phase shift under different conditions suggest that there may exist an optimum capacitance for which the thermal stability of the system can be most enhanced.
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| 10. |
- Zhou, Ye, 1971-, et al.
(författare)
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Chitosan-N-poly (ethylene oxide) brush polymers for reduced nonspecific protein adsorption
- 2007
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Ingår i: Journal of Colloid and Interface Science. - : Elsevier BV. - 0021-9797 .- 1095-7103. ; 305:1, s. 62-71
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Tidskriftsartikel (refereegranskat)abstract
- The possibility of using a novel comb polymer consisting of a chitosan backbone with grafted 44 units long poly(ethylene oxide) side chains for reducing nonspecific protein adsorption to gold surfaces functionalized by COOH-terminated thiols has been explored. The comb polymer was attached to the surface in three different ways: by solution adsorption, covalent coupling, and microcontact printing. The protein repellant properties were tested by monitoring the adsorption of bovine serum albumin and fibrinogen employing surface plasmon resonance and imaging null ellipsometry. It was found that a significant reduction in protein adsorption is achieved as the comb polymer layer is sufficiently dense. For solution adsorption this was achieved by adsorption from high pH solutions. On the other hand, the best performance of the microcontact printed surfaces was obtained when the stamp was inked either at low or at high pH. For a given comb polymer layer thickness/poly(ethylene oxide) density, significant differences in protein repellant properties were observed between the different preparation methods, and it is suggested that a reduction in the mobility of the comb polymer layer generated by covalent attachment favors a reduced protein adsorption. (c) 2006 Elsevier Inc. All rights reserved.
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