Showing papers by "Yu Huang published in 2005"

Programmable assembly of nanoarchitectures using genetically engineered viruses.

Abstract: Biological systems possess inherent molecular recognition and self-assembly capabilities and are attractive templates for constructing complex material structures with molecular precision. Here we report the assembly of various nanoachitectures including nanoparticle arrays, hetero-nanoparticle architectures, and nanowires utilizing highly engineered M13 bacteriophage as templates. The genome of M13 phage can be rationally engineered to produce viral particles with distinct substrate-specific peptides expressed on the filamentous capsid and the ends, providing a generic template for programmable assembly of complex nanostructures. Phage clones with gold-binding motifs on the capsid and streptavidin-binding motifs at one end are created and used to assemble Au and CdSe nanocrytals into ordered one-dimensional arrays and more complex geometries. Initial studies show such nanoparticle arrays can further function as templates to nucleate highly conductive nanowires that are important for addressing/interconne...

Biological properties of baicalein in cardiovascular system

Abstract: The dried roots of Scutellaria baicalensis (S. baicalensis) Georgi (common name: Huangqin in China) have been widely employed for many centuries in traditional Chinese herbal medicine as popular antibacterial and antiviral agents. They are effective against staphylococci, cholera, dysentery, pneumococci and influenza virus. Baicalein, one of the major flavonoids contained in the dried roots, possesses a multitude of pharmacological activities. The glycoside of baicalein, baicalin is a potent anti-inflammatory and anti-tumor agent. This review describes the biological properties of baicalein (Table 1), which are associated with the prevention and treatment of cardiovascular diseases. Baicalein is a potent free radical scavenger and xanthine oxidase inhibitor, thus improving endothelial function and conferring cardiovascular protective actions against oxidative stress-induced cell injury. Baicalein lowers blood pressure in renin-dependent hypertension and the in vivo hypotensive effect may be partly attributed to its inhibition of lipoxygenase, resulting in reduced biosynthesis and release of arachidonic acid-derived vasoconstrictor products. On the other hand, baicalein enhances vasoconstricting sensitivity to receptor-dependent agonists such as noradrenaline, phenylephrine, serotonin, U46619 and vasopressin in isolated rat arteries. The in vitro effect is likely caused by inhibition of an endothelial nitric oxide-dependent mechanism. The anti-thrombotic, anti-proliferative and anti-mitogenic effects of the roots of S. baicalensis and baicalein are also reported. Baicalein inhibits thrombin-induced production of plasminogen activator inhibitor-1, and interleukin-1beta- and tumor necrosis factor-alpha-induced adhesion molecule expression in cultured human umbilical vein endothelial cells. The pharmacological findings have highlighted the therapeutic potentials of using plant-derived baicalein and its analogs for the treatment of arteriosclerosis and hypertension.

Distribution, depletion and recovery of docosahexaenoic acid are region-specific in rat brain.

Abstract: The present study examined: (i) age-induced regional changes in fatty acid composition of brain phospholipids; (ii) alpha-linolenic acid deficiency-induced regional depletion and recovery of DHA in the brain. DHA and arachidonic acid (AA) did not distribute evenly in the brain. In weaning and adult rats, the region with the highest DHA percentage was the cortex whereas the medulla had the lowest DHA percentage. In the aged rats, both the cortex and cerebellum were the regions with the highest DHA percentage whereas in the neonatal rats, the striatum had the greatest percentage of DHA, and the hypothalamus and hippocampus had the least percentage of DHA. Regarding AA, the hippocampus was the region that had the highest percentage whereas the medulla was the region with the lowest percentage except for the neonatal rats, whose cerebellum, hypothalamus, striatum and midbrain had AA percentage lower than hippocampus and cortex. DHA was not proportionally depleted in various regions of brain when the rats were maintained on an n-3-deficient diet for two generations. The results demonstrated that the cortex, hippocampus, striatum, cerebellum and hypothalamus had DHA depleted by >71 %, whereas the midbrain and medulla had only 64 and 57 % DHA depleted, respectively. The most important observation was that the diet reversal for 12 weeks resulted in complete DHA recovery in all regions except for the medulla where the recovery was only 62 %. It was concluded that the location of DHA, n-3 deficiency-induced DHA depletion and reversibility of DHA deficiency across the brain were region-specific.

Acetylcholine and sodium nitroprusside cause long-term inhibition of EDCF-mediated contractions

Abstract: Preliminary studies suggested that previous exposure to acetylcholine (ACh) exerts a delayed inhibition of subsequent contractions mediated by endothelium-derived contracting factor (EDCF). To conf...

Regulation of TRP channels by phosphorylation.

Abstract: The transient receptor potential (TRP) channels are a group of Ca2+-permeable cation channels (except TRPM4 and TRPM5) that function as cellular sensors of various internal and external stimuli. Most of these channels are expressed in the nervous system and they play a key role in sensory physiology. They may respond to temperature, pressure, inflammatory agents, pain, osmolarity, taste and many other stimuli. Recent development indicates that the activity of these channels is regulated by protein phosphorylation and dephosphorylation of serine, threonine, and tyrosine residues. In this review, we present a comprehensive summary of the literature regarding the TRP channel regulation by different protein kinases.

α-Linolenic acid but not conjugated linolenic acid is hypocholesterolaemic in hamsters

Abstract: Conjugated linolenic acid (CLN) refers to a group of octadecatrienoic acid isomers that have three double bonds in conjugation. Both pomegranate and tung seed oils are rich in CLN but the major isomer in the former is cis9,trans11,cis13 while in the latter it is cis9,trans11,trans13. The present study examined the effects of CLN, isolated from either pomegranate seed oil or tung seed oil, and alpha-linolenic acid (LN), isolated from flaxseed oil, on serum cholesterol levels in male hamsters (body weight 105 g; age 10 weeks) fed a 0.1% cholesterol and 10% lard diet, for a period of 6 weeks. All hamsters were allowed free access to food and fluid. The blood samples were taken by bleeding from the retro-orbital sinus into a heparinized capillary tube under light ether anaesthesia after overnight fasting at weeks 0, 2, 4 and 6. It was found that supplementation of CLN at levels of 12.2-12.7 g/kg diet exhibited no significant effect on serum cholesterol level while LN at a similar level of supplementation had serum cholesterol reduced by 17-21% compared with the control diet containing no LN and CLN. Supplementation of CLN and LN significantly decreased hepatic cholesterol but no effect was observed on heart and kidney cholesterol levels. It was concluded that LN possessed hypocholesterolaemic activity while CLN had no effect on blood cholesterol, at least in hamsters.

Compressed pattern diagnosis for scan chain failures

Abstract: In scan based designs, 10%-30% defects are in scan chains. Hence scan chain fault diagnosis becomes an important process for silicon debug and yield ramp up. With embedded compression techniques getting popular, chain diagnosis on devices with the embedded compression techniques becomes a challenge. In this paper, we provide a general methodology that can be applied for performing chain diagnosis in the context of any embedded compression techniques with any existing chain diagnosis algorithms. The proposed methodology enables seamless reuse of the existing chain diagnosis infrastructure with compressed test data. Experimental results show that with compressed patterns, the chain diagnosis resolution can be enhanced up to one order of magnitude with only 25% of failure cycles collected from ATE, compared to the diagnosis results with uncompressed patterns

Compactor independent direct diagnosis of test hardware

Abstract: Methods, apparatus, and systems for performing fault diagnosis are disclosed herein. In one exemplary embodiment, a failure log is received comprising entries indicative of compressed test responses to chain patterns and compressed test responses to scan patterns. A faulty scan chain in the circuit-under-test is identified based at least in part on one or more of the entries indicative of the compressed test responses to chain patterns. One or more faulty scan cell candidates in the faulty scan chain are identified based at least in part on one or more of the entries indicative of the compressed test responses to scan patterns. The one or more identified scan cell candidates can be reported. Computer-readable media comprising computer-executable instructions for causing a computer to perform any of the disclosed methods are also provided. Likewise, computer-readable media storing lists of fault candidates identified by any of the disclosed methods are also provided.

Urocortin-induced relaxation in the human internal mammary artery.

Abstract: Objective : Urocortin, a potent vasodilator, plays physiological or pathophysiological roles in the cardiovascular system. However, little is known about its action in human vascular tissues. The present study was designed to investigate the vascular effect of urocortin on human internal mammary artery (IMA) in vitro and the possible underlying mechanisms. Methods : Human IMA was obtained from patients undergoing coronary artery bypass grafting. The isolated IMA rings were mounted in organ baths and changes in isometric tension were measured by using Grass force–displacement transducer. Corticortropin-releasing factor-receptors (CRF-R) were also analyzed in the IMA by using RT-PCR analysis. Results : In 9,11-dideoxy-11α,9α-epoxy-methanoprostaglandin F2α (U46619)-precontracted endothelium-intact rings, urocortin induced concentration-dependent relaxations with p D 2 of 8.69 ± 0.11 and this effect was markedly reduced in endothelium-denuded rings. Relaxations to urocortin in endothelium-intact rings were attenuated to the same extent after treatment with N G -nitro-l-arginine (l-NNA) and 1H-[1,2,4]oxadizolo[4,3-a]quinoxalin-1-one (ODQ). Urocortin-induced relaxations were also inhibited by treatment with putative K+ channel blockers, such as tetraethylammonium (TEA+), charybdotoxin (CTX), and iberiotoxin (IBX). In endothelium-denuded rings, treatment with TEA+, CTX, or IBX attenuated relaxation to urocortin as well as sodium nitroprusside (SNP). The bands for CRF-R1, CRF-R2α, and CRF-R2β mRNAs were observed in both endothelium-intact and endothelium-denuded human IMA. Conclusion : Urocortin produced both endothelium-dependent and -independent relaxation in human IMA rings. The endothelium-dependent component primarily involves the release of endothelial nitric oxide (NO) that in turn stimulates Ca2+-activated K+ channels in vascular smooth muscle via cyclic GMP-dependent mechanisms. CRF-R1, CRF-R2α, and CRF-R2β mRNAs are present in the human IMA.

Policosanol has no antioxidant activity in human low-density lipoprotein but increases excretion of bile acids in hamsters.

Abstract: Policosanol is a group of long chain primary alcohols and has been shown to reduce blood cholesterol levels and to inhibit the oxidation of low-density lipoprotein (LDL). The present study examined (i) the effect of policosanol supplementation in the diet on the fecal excretion of neutral and acidic sterols in hamsters and (ii) the antioxidant activity of policosanol in human LDL. Golden Syrian hamsters were divided into four groups (n = 12/each) fed one of the four diets containing 0 (control), 0.38, 0.75, and 1.50 g kg(-1) policosanol for 6 weeks. It was found that hamsters given 0.38-1.5 g kg(-1) diets had a serum total cholesterol level lowered by 15-25% and had a high-density lipoprotein cholesterol elevated by 7-16.8%. It was found that policosanol increased the excretion of acidic sterols by 25-73%. Contrary to that in previous reports, policosanol had no apparent anti-LDL oxidation activity when 1-tetracosanol, 1-hexacosanol, and 1-octacosanol were incubated in human LDL. Policosanol also possessed no scavenging activity on the free radical2,2-diphenyl-1-picrylhydrazyl. These data provide evidence that in addition to the effect of HMG-CoA reductase, the cholesterol-lowering activity of policosanol is partially mediated by its inhibition on the absorption of bile acids, but these data disprove the claim that policosanol is an antioxidant.

Compactor independent fault diagnosis

Abstract: Methods, apparatus, and systems for performing fault diagnosis are disclosed herein. In certain disclosed embodiments, methods for diagnosing faults from compressed test responses are provided. For example, in one exemplary embodiment, a circuit description of an at least partially scan-based circuit-under-test and a compactor for compacting test responses captured in the circuit-under-test is received. A transformation function performed by the compactor to the test responses captured in the circuit-under-test is determined. A diagnostic procedure for evaluating uncompressed test responses is modified into a modified diagnostic procedure that incorporates the transformation function therein. Computer-readable media comprising computer-executable instructions for causing a computer to perform any of the disclosed methods are also provided. Likewise, computer-readable media comprising lists of fault candidates identified by any of the disclosed methods or circuit descriptions created or modified by the disclosed methods are provided.

Using fault model relaxation to diagnose real scan chain defects

Abstract: Software-based scan chain fault diagnosis is typically composed of two steps. First, scan chain flush patterns are used to identify faulty chains and fault models. This is followed by chain diagnosis using scan patterns in the second step. In this paper, we target chain diagnosis on one special category of chain faults: intermittent scan chain faults. It is showed that these faults may not be modeled correctly in the first step. Hence, a novel diagnosis methodology based on scan chain fault model relaxation is proposed.

Raloxifene relaxes rat intrarenal arteries by inhibiting Ca2+ influx

Abstract: Raloxifene may confer vascular benefits without causing estrogen-related side effects. However, its action on renal vascular circulation is unknown. This study aimed to examine the sex difference a...

Raloxifene Relaxes Rat Pulmonary Arteries and Veins: Roles of Gender, Endothelium, and Antagonism of Ca2+ Influx

Abstract: Effects of raloxifene have been documented in the systemic circulation. However, its impact on the pulmonary circulation is unclear. The present study investigated the role of gender, endothelial modulation, and Ca2+ channel in relaxations evoked by raloxifene in rat pulmonary arteries and veins. Vascular responses were studied on isolated pulmonary blood vessels mounted in a myograph and constricted by U46619 (9,11-dideoxy-11α,9α-epoxymethanoprostaglandin F2α). Constrictions to CaCl2 were studied in Ca2+-free, 60 mM K+ solution. Changes in the intracellular calcium ion concentration ([Ca2+]i) in vascular smooth muscle were measured using a calcium fluorescence imaging method. Raloxifene was more effective in relaxing U46619-constricted pulmonary arteries from male than female rats. Raloxifene-induced relaxation was unaffected by ICI 182,780 [7α-[9-[(4,4,5,5,5,-pentafluoropentyl)-sulfinyl]nonyl]-estra-1,3,5(10)-triene-3,17β-diol], inhibition of the nitric oxide (NO) pathway, or removal of the endothelium. In arteries without endothelium, raloxifene attenuated CaCl2-induced constriction and CaCl2-stimulated increase in [Ca2+]i with similar potencies. Raloxifene caused endothelium-independent relaxations in pulmonary veins, albeit to a lesser degree than in pulmonary arteries. The venous responses showed a gender difference because raloxifene was more potent in male veins. In summary, raloxifene relaxed rat pulmonary arteries, and this effect did not involve the endothelium/NO or ICI 182,780-sensitive estrogen receptors. Raloxifene, like nifedipine, reduced constriction and [Ca2+]i increase in response to CaCl2 in high K+ solution. Raloxifene also relaxed high K+-constricted pulmonary veins. Our data indicate that raloxifene acutely relaxes rat pulmonary blood vessels primarily via inhibition of Ca2+ influx through voltage-sensitive Ca2+ channels. Finally, raloxifene induced more relaxation in blood vessels isolated from male than female rats.

Human scFv antibody fragments specific for hepatocellular carcinoma selected from a phage display library.

Abstract: Human scFv antibody fragments specific for hepatocellular carcinoma selected from a phage display library

Prediction of marine sediment corrosion by fuzzy clustering analysis

Abstract: Along with the development of marine industries, especially marine petroleum exploitation, more and more pipelines are buried in the marine sediment It is necessary and useful to know the corrosion environment and corrosiveness of marine sediment In this paper, field corrosion environmental factors were investigated in Liaodong Bay marine sediment containing sulfate-reducing bacteria (SRB) and corrosion rate of steel in the partly sediment specimens were determined by the transplanting burying method Based on the data, the fuzzy clustering analysis (FCA) was applied to evaluate and predict the corrosiveness of marine sediment On that basis, the influence factors of corrosion damage were discussed

Quantification and characterization of aortic cholesterol in rabbits fed a high-cholesterol diet.

Abstract: Determination of fat percentage of aortic intimal area stained by Sudan III is useful as an index of atherosclerosis in the rabbit animal model. However, the determination of sudanophilic area of the thoracic aorta is two-dimensional and does not measure the third dimension of depth. The objective of the present study was to quantify and characterize aortic lipids using the gas-liquid chromatographic (GLC) technique and to determine whether elevated measurements of total cholesterol and cholesteryl esters was correlated with increased measurements of sudanophilic area staining of the thoracic aorta in rabbits given either a normal chow or a 1% cholesterol diet. The GLC results showed that there was a mean accumulation of 10.9 mg of cholesterol per gram of aortic tissue in the rabbits given a cholesterol diet (mean sudanophilic area of 23.8%). In contrast, rabbits on a normal chow diet had only a deposition of 0.58 mg of cholesterol per gram of the aortic tissue diet (mean sudanophilic area of 1.4%). The present study suggests that quantification of the aortic lipids can be performed by using GLC techniques and that it could be used as an alternative to the measurement of sudanophilic area when assessing the severity of atherosclerosis.

Integrated Nanoscale Electronics and Optoelectronics: Exploring Nanoscale Science and Technology Through Semiconductor Nanowires

Abstract: Semiconductor nanowires (NWs) represent an ideal system for investigating low- dimensional physics and are expected to play an important role as both interconnects and functional device elements in nanoscale electronic and optoelectronic devices. Here we re- view a series of key advances defining a new paradigm of bottom-up assembling integrated nanosystems using semiconductor NW building blocks. We first introduce a general ap- proach for the synthesis of a broad range of semiconductor NWs with precisely controlled chemical composition, physical dimension, and electronic, optical properties using a metal cluster-catalyzed vapor-liquid-solid growth mechanism. Subsequently, we describe rational strategies for the hierarchical assembly of NW building blocks into functional devices and complex architectures based on electric field or micro-fluidic flow. Next, we discuss a vari- ety of new nanoscale electronic device concepts including crossed NW p-n diode and crossed NW field effect transistors (FETs). Reproducible assembly of these scalable crossed NW de- vice elements enables a catalog of integrated structures, including logic gates and computa- tional circuits. Lastly, we describe a wide range of photonic and optoelectronic devices, in- cluding nanoscale light-emitting diodes (nanoLEDs), multicolor LED arrays, integrated nanoLED-nanoFET arrays, single nanowire waveguide, and single nanowire nanolaser. The potential application of these nanoscale light sources for chemical and biological analyses is discussed.

Mode properties of off-axis one-sided hybrid resonator for novel high average power dual-slab laser

Abstract: A novel dual-slab laser with off-axis one-sided hybrid resonator is presented. The mode properties of the hybrid resonator are calculated using a fast Fourier transform method (FFT). The influence of wavefront distoration on the output beam quality is considered. Results indicate that the novel dual-slab laser is better than the normal dual-slab laser with off-axis one-sided hybrid resonator.

Off-shore outsource DFT vs. build off-shore branch offices

Abstract: Outsourcing is the result of maturation in an industry: as an industry matures, skills are automated and inevitably become commoditized. When commoditization occurs, the work goes to those who best compete with the lowest common denominators of trained labor, low-cost resources, and affordable capital. Outsourcing seems to be an attractive means for cost containment for semiconductor industry as both market and profit margins have tightened. Corporations should focus on core and outsource context. Core means the activity that directly affects the competitive advantage of an organization, which differentiates a company from its competitors. All other activities are context. The good news is that one company's context may be another company's core