Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 35
Filtrar
Filtros adicionais











País/Região como assunto
Intervalo de ano
1.
J Nanosci Nanotechnol ; 20(2): 760-768, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383071

RESUMO

Enhancing the mobility in metal-oxide-semiconductor field-effect transistors (MOSFETs) with narrow channel widths is highly sensitive to the stress effects of Si channel when related advanced strain engineering is introduced and is compatible with semiconductor processes. In practice, layouts have significant effect on the device performance, especially for the protruding gate width on shallow trench isolation structures. The geometric parameter is investigated by systematically analysing an n-channel MOSFET composed of silicon-carbon (SiC) stressors embedded in the source and drain (S/D) regions and a tensile contact etch stop layer (CESL) using three-dimensional finite element simulation. Tensile CESL (1.1 GPa) and a SiC S/D stressor with a carbon mole fraction of 1.65% are loaded on the structure. The difference in the interactive percentages between the mechanical bending effect of the CESL from the top of the poly gate and the downward force of the CESL adjacent to the spacer sidewall of the gate occurs when the protruding gate width is increased. Results indicate that mobility was highly enhanced by approximately 72.5% at a width of approximately 0.2 µm. The mechanical bending effect becomes dominant when the gate width is more than 0.2 µm. Consequently, the mobility gain decays and consequently converges toward a constant.

2.
J Am Chem Soc ; 140(15): 5202-5210, 2018 04 18.
Artigo em Inglês | MEDLINE | ID: mdl-29578688

RESUMO

The development of an HIV vaccine has been hampered by the extraordinary mutability and genetic diversity of the virus, particularly the substantial sequence diversity of gp120 and gp 41 envelope glycoproteins existing in more than 2000 HIV variants. The highly diverse glycans on HIV spikes are commonly considered as immunologically silent self-antigens; however, the discovery of highly potent broadly neutralizing antibodies (bNAbs) from HIV patients targeting the viral surface glycans has raised a major question about the origin of their antigens. Recent epitope mapping studies of the bNAb PG9 indicated a requirement of a properly spaced high mannose and a complex type glycan connected by a short peptide spacer. We have recently discovered that a 1:1 mixture of Man5 and sialyl biantennary glycan with well-defined distance and without the peptide spacer is well recognized by PG9 with high avidity and, thus, proposed that a hybrid glycan with oligomannose and complex-type arm could be the proper ligand of PG9. To verify this proposition, we first designed and chemo-enzymatically synthesized a series of unusual hybrid-type N-glycan structures, which may exist on HIV surface glycoproteins through the host-guided N-glycosylation pathway. The synthetic hybrid glycans were then used to prepare glycan arrays for the binding studies of PG9 and several other highly potent bNAbs, including PG16, PGT121, PGT128-3C, 2G12, VRC13, VRC-PG05, VRC26.25, VRC26.09, PGDM1400, 35O22, and 10-1074. Our results demonstrated that PG9 and some other bNAbs bind with strong avidity (subnanomolar Kd) to certain hybrid structures, suggesting that these unusual glycans may serve as epitopes for the design of vaccines against HIV.


Assuntos
Anticorpos Neutralizantes/imunologia , HIV-1/imunologia , Polissacarídeos/imunologia , Anticorpos Neutralizantes/química , HIV-1/química , Humanos , Ligantes , Polissacarídeos/química
3.
Immunity ; 48(3): 500-513.e6, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29548671

RESUMO

Virtually the entire surface of the HIV-1-envelope trimer is recognized by neutralizing antibodies, except for a highly glycosylated region at the center of the "silent face" on the gp120 subunit. From an HIV-1-infected donor, #74, we identified antibody VRC-PG05, which neutralized 27% of HIV-1 strains. The crystal structure of the antigen-binding fragment of VRC-PG05 in complex with gp120 revealed an epitope comprised primarily of N-linked glycans from N262, N295, and N448 at the silent face center. Somatic hypermutation occurred preferentially at antibody residues that interacted with these glycans, suggesting somatic development of glycan recognition. Resistance to VRC-PG05 in donor #74 involved shifting of glycan-N448 to N446 or mutation of glycan-proximal residue E293. HIV-1 neutralization can thus be achieved at the silent face center by glycan-recognizing antibody; along with other known epitopes, the VRC-PG05 epitope completes coverage by neutralizing antibody of all major exposed regions of the prefusion closed trimer.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Polissacarídeos/imunologia , Sequência de Aminoácidos , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/genética , Anticorpos Neutralizantes/metabolismo , Antígenos Virais/química , Antígenos Virais/imunologia , Sítios de Ligação , Mapeamento de Epitopos , Epitopos/química , Epitopos/imunologia , Epitopos/metabolismo , Glicopeptídeos/química , Glicopeptídeos/imunologia , Glicosilação , Anticorpos Anti-HIV/química , Anticorpos Anti-HIV/genética , Anticorpos Anti-HIV/metabolismo , Proteína gp120 do Envelope de HIV/química , Proteína gp120 do Envelope de HIV/metabolismo , Humanos , Modelos Moleculares , Conformação Molecular , Polissacarídeos/química , Ligação Proteica/imunologia , Hipermutação Somática de Imunoglobulina/imunologia , Relação Estrutura-Atividade
4.
Materials (Basel) ; 10(10)2017 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-29064435

RESUMO

The microbump (µ-bump) reliability of 3D integrated circuit (3D-IC) packaging must be enhanced, in consideration of the multi-chip assembly, during temperature cycling tests (TCT). This research proposes vehicle fabrications, experimental implements, and a nonlinear finite element analysis to systematically investigate the assembled packaging architecture that stacks four thin chips through the wafer level underfill (WLUF) process. The assembly of µ-bump interconnects by daisy chain design shows good quality. Results of both TCT data and the simulation indicate that µ-bumps with residual SnAg solders can reach more than 1200 fatigue life cycles. Moreover, several important design factors in the present 3D-IC package influence µ-bump reliability. Analytical results show that the µ-bump's thermo-mechanical reliability can be improved by setting proper chip thickness, along with a WLUF that has a low elastic modulus and a small coefficient of thermal expansion.

5.
Proc Natl Acad Sci U S A ; 114(2): 280-285, 2017 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-28028222

RESUMO

We have shown that glycosylation of influenza A virus (IAV) hemagglutinin (HA), especially at position N-27, is crucial for HA folding and virus survival. However, it is not known whether the glycosylation of HA and the other two major IAV surface glycoproteins, neuraminidase (NA) and M2 ion channel, is essential for the replication of IAV. Here, we show that glycosylation of HA at N-142 modulates virus infectivity and host immune response. Glycosylation of NA in the stalk region affects its structure, activity, and specificity, thereby modulating virus release and virulence, and glycosylation at the catalytic domain affects its thermostability; however, glycosylation of M2 had no effect on its function. In addition, using IAV without the stalk and catalytic domains of NA as a live attenuated vaccine was shown to confer a strong IAV-specific CD8+ T-cell response and a strong cross-strain as well as cross-subtype protection against various virus strains.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Células A549 , Animais , Anticorpos Antivirais/imunologia , Linfócitos T CD8-Positivos/imunologia , Linhagem Celular , Linhagem Celular Tumoral , Proteção Cruzada/imunologia , Cães , Feminino , Células HEK293 , Humanos , Influenza Humana/imunologia , Influenza Humana/prevenção & controle , Células Madin Darby de Rim Canino , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Virulência/imunologia
6.
Avian Dis ; 60(1 Suppl): 156-71, 2016 05.
Artigo em Inglês | MEDLINE | ID: mdl-27309051

RESUMO

The largest epidemic of avian influenza (AI) in history attacked poultry and wild birds throughout Taiwan starting January 6, 2015. This study analyzed surveillance results, epidemiologic characteristics, and viral sequences by using government-released information, with the intention to provide recommendations to minimize future pandemic influenza. The H5 clade 2.3.4.4 highly pathogenic AI viruses (HPAIVs) had not been detected in Taiwan before 2015. During this epidemic, four types of etiologic agents were identified: the three novel subtypes H5N2, H5N8, and H5N3 clade 2.3.4.4 HPAIVs and one endemic chicken H5N2 subtype (Mexican-like lineage) of low pathogenic AI viruses. Cocirculation of mixed subtypes also occurred, with H5N2 clade 2.3.4.4 HPAIVs accompanied by the H5N8 and H5N3 subtypes or old H5N2 viruses in the same farm. More than 90% of domestic geese died from this AI epidemic; geese were affected the most at the early outbreaks. The epidemic peaked in mid-January for all three novel H5 subtypes. Spatial epidemiology found that most affected areas were located in southwestern coastal areas. In terrestrial poultry (mostly chickens), different geographic distributions of AI virus subtypes were detected, with hot spots of H5N2 clade 2.3.4.4 vs. past-endemic old H5N2 viruses in Changhwa (P = 0.03) and Yunlin (P = 0.007) counties, respectively, of central Taiwan. Phylogenetic and sequence analyses of all the early 10 Taiwan H5 clade 2.3.4.4 isolates covering the three subtypes showed that they were very different from the HA of the past local H5 viruses from domestic ducks (75%-80%) and chickens (70%-75%). However, they had the highest sequence identity percentages (99.53%-100%), with the HA of A/crane/Kagoshima/KU13/2014(H5N8) isolated on December 7, 2014, in Japan being higher than those of recent American and Korean H5 HPAIVs [A/Northern pintail/Washington/40964/2014 (H5N2) and A/gyrfalcon/Washington/41088-6/2014 (H5N8): 99.02%-99.54% and A/Baikal teal/Korea/Donglim3/2014 (H5N8): 98.61%-99.08%], implying a likely common ancestor of these H5 clade 2.3.4.4 viruses. The multiple subtypes of H5 clade 2.3.4.4 HPAIVs imply high viral reassortment. We recommend establishing an integrated surveillance system, involving clinical, virologic, and serologic surveillance in poultry and wild birds, swine and other mammals prevalent on multiple-animal mixed-type traditional farms, and high-risk human populations, as a crucially important step to minimize future pandemic influenza.


Assuntos
Vírus da Influenza A/isolamento & purificação , Influenza Aviária/epidemiologia , Doenças das Aves Domésticas/epidemiologia , Animais , Animais Selvagens/virologia , Galinhas , Surtos de Doenças , Patos , Gansos , Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/virologia , Filogenia , Doenças das Aves Domésticas/virologia , Taiwan/epidemiologia
7.
Cell ; 165(4): 813-26, 2016 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-27114034

RESUMO

The HIV-1-envelope (Env) trimer is covered by a glycan shield of ∼90 N-linked oligosaccharides, which comprises roughly half its mass and is a key component of HIV evasion from humoral immunity. To understand how antibodies can overcome the barriers imposed by the glycan shield, we crystallized fully glycosylated Env trimers from clades A, B, and G, visualizing the shield at 3.4-3.7 Å resolution. These structures reveal the HIV-1-glycan shield to comprise a network of interlocking oligosaccharides, substantially ordered by glycan crowding, that encase the protein component of Env and enable HIV-1 to avoid most antibody-mediated neutralization. The revealed features delineate a taxonomy of N-linked glycan-glycan interactions. Crowded and dispersed glycans are differently ordered, conserved, processed, and recognized by antibody. The structures, along with glycan-array binding and molecular dynamics, reveal a diversity in oligosaccharide affinity and a requirement for accommodating glycans among known broadly neutralizing antibodies that target the glycan-shielded trimer.


Assuntos
HIV-1/química , Produtos do Gene env do Vírus da Imunodeficiência Humana/química , Anticorpos Neutralizantes/metabolismo , Anticorpos Antivirais/metabolismo , Cristalografia por Raios X , Glicosilação , HIV-1/classificação , HIV-1/imunologia , Evasão da Resposta Imune , Modelos Moleculares , Simulação de Dinâmica Molecular , Polissacarídeos/análise , Polissacarídeos/metabolismo
8.
Nat Chem ; 8(4): 338-46, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27001729

RESUMO

A new class of broadly neutralizing antibodies (bNAbs) from HIV donors has been reported to target the glycans on gp120--a glycoprotein found on the surface of the virus envelope--thus renewing hope of developing carbohydrate-based HIV vaccines. However, the version of gp120 used in previous studies was not from human T cells and so the glycosylation pattern could be somewhat different to that found in the native system. Moreover, some antibodies recognized two different glycans simultaneously and this cannot be detected with the commonly used glycan microarrays on glass slides. Here, we have developed a glycan microarray on an aluminium-oxide-coated glass slide containing a diverse set of glycans, including homo- and mixed N-glycans (high-mannose, hybrid and complex types) that were prepared by modular chemo-enzymatic methods to detect the presence of hetero-glycan binding behaviours. This new approach allows rapid screening and identification of optimal glycans recognized by neutralizing antibodies, and could speed up the development of HIV-1 vaccines targeting cell surface glycans.


Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Anti-HIV/imunologia , HIV-1/imunologia , Polissacarídeos/síntese química , Vacinas contra a AIDS/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Humanos , Ligantes , Polissacarídeos/química , Polissacarídeos/imunologia
9.
Materials (Basel) ; 9(9)2016 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-28773838

RESUMO

Stress-induced failure is a critical concern that influences the mechanical reliability of an indium tin oxide (ITO) film deposited on a transparently flexible polyethylene terephthalate (PET) substrate. In this study, a cycling bending mechanism was proposed and used to experimentally investigate the influences of compressive and tensile stresses on the mechanical stability of an ITO film deposited on PET substrates. The sheet resistance of the ITO film, optical transmittance of the ITO-coated PET substrates, and failure scheme within the ITO film were measured to evaluate the mechanical stability of the concerned thin films. The results indicated that compressive and tensile stresses generated distinct failure schemes within an ITO film and both led to increased sheet resistance and optical transmittance. In addition, tensile stress increased the sheet resistance of an ITO film more easily than compressive stress did. However, the influences of both compressive and tensile stress on increased optical transmittance were demonstrated to be highly similar. Increasing the thickness of a PET substrate resulted in increased sheet resistance and optical transmittance regardless of the presence of compressive or tensile stress. Moreover, J-Integral, a method based on strain energy, was used to estimate the interfacial adhesion strength of the ITO-PET film through the simulation approach enabled by a finite element analysis.

10.
Materials (Basel) ; 9(10)2016 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-28773969

RESUMO

The suitability of stacked thin films for next-generation display technology was analyzed based on their properties and geometrical designs to evaluate the mechanical reliability of transparent conducting thin films utilized in flexural displays. In general, the high bending stress induced by various operation conditions is a major concern regarding the mechanical reliability of indium-tin-oxide (ITO) films deposited on polyethylene terephthalate (PET) substrates; mechanical reliability is commonly used to estimate the flexibility of displays. However, the pattern effect is rarely investigated to estimate the mechanical reliability of ITO/PET films. Thus, this study examined the flexible content of patterned ITO/PET films with two different line widths by conducting bending tests and sheet resistance measurements. Moreover, a stress-strain simulation enabled by finite element analysis was performed on the patterned ITO/PET to explore the stress impact of stacked film structures under various levels of flexural load. Results show that the design of the ITO/PET film can be applied in developing mechanically reliable flexible electronics.

11.
Infect Genet Evol ; 38: 96-100, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26690663

RESUMO

Phylogenetic analysis of the highly pathogenic avian influenza (HPAI) H5 viruses causing recent outbreaks in Taiwan showed that they belonged to the Asian HPAI H5 lineage, clade 2.3.4.4 viruses, and were apparently introduced by migratory birds. These viruses reassorted with Eurasian influenza gene pool viruses and formed five genotypic variants. As Taiwan has a similar influenza ecosystem to southern China, the HPAI H5 lineage could become established and enzootic in the island.


Assuntos
Vírus da Influenza A/classificação , Vírus da Influenza A/genética , Influenza Aviária/virologia , Animais , Genes Virais , Genótipo , Geografia Médica , Influenza Aviária/epidemiologia , Filogenia , Filogeografia , Aves Domésticas , Taiwan/epidemiologia
12.
J Nanosci Nanotechnol ; 15(3): 2173-8, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26413636

RESUMO

In this research, an n-type metal-oxide-semiconductor field effect transistor (nMOSFET) device with a SiGe channel exerted by the combination of a contact etching stop layer (CESL) and silicon germanium (Si1-xGe(x)) channel stressors is proposed. To explore the foregoing mechanical effect on the stress distribution of nMOSFETs within the channel region, a process-oriented simulated technique is adopted for the concerned nMOSFET device. The loading sources are a 1.1 GPa tensile CESL (t-CESL) and a SiGe channel structure constructed with 0%, 22.5%, and 25%, germanium (Ge) mole fractions. The results of the simulation show that the stress components of the Si1-xGe(x) channel evidently increase when the Ge mole fraction within a Si1-xGe(x) layer is increased. A pulling force exerted on the protruding gate structure by the CESL layer that causes dominant bending deformation and channel stress variation behaviors is a major reason for this phenomenon. Therefore, the degree of bending effect caused by the protruding gate structure is concluded as being the key to determining the trends and stress magnitudes of the Si1-xGe(x) device channel.

13.
J Nanosci Nanotechnol ; 15(3): 2179-84, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26413637

RESUMO

As the strained engineering technology of metal-oxide-semiconductor field effect transistors (MOSFET) is scaled beyond the 22 nm node critical dimension, shallow trench isolation (STI) becomes one of the most important resolutions for isolate devices to enhance the carrier mobility of advanced transistors. Several key design factors of n-type MOSFET (NMOSFET) under the resultant loadings of STI structures and contact etching stop layers are sensitively analyzed for silicon channel stress via finite element method-based simulations integrated with the use of design of experienmnts. NMOSFETs with 15 nm deep sunken STI have achieved a ~5% mobility enhancement as compared with a regular STI shape. By adopting simulation-based factorial designs, we have determined that the design factor of recess depth in STI is a critical factor influencing device performance. Moreover, a response surface curve on carrier mobility of NMOSFET under a consideration of combining the sunken STI and source/drain lengths is further presented in this research.

14.
PLoS One ; 10(8): e0133910, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26263554

RESUMO

BACKGROUND: Human infections with avian influenza viruses (AIVs) have frequently raised global concerns of emerging, interspecies-transmissible viruses with pandemic potential. Waterfowl, the predominant reservoir of influenza viruses in nature, harbor precursors of different genetic lineages that have contributed to novel pandemic influenza viruses in the past. METHODS: Two duck influenza H5N2 viruses, DV518 and DV413, isolated through virological surveillance at a live-poultry market in Taiwan, showed phylogenetic relatedness but exhibited different replication capabilities in mammalian Madin-Darby Canine Kidney (MDCK) cells. This study characterizes the replication properties of the two duck H5N2 viruses and the determinants involved. RESULTS: The DV518 virus replicated more efficiently than DV413 in both MDCK and chicken DF1 cells. Interestingly, the infection of MDCK cells by DV518 formed heterogeneous plaques with great differences in size [large (L) and small (S)], and the two viral strains (p518-L and p518-S) obtained from plaque purification exhibited distinguishable replication kinetics in MDCK cells. Nonetheless, both plaque-purified DV518 strains still maintained their growth advantages over the plaque-purified p413 strain. Moreover, three amino acid substitutions in PA (P224S), PB2 (E72D), and M1 (A128T) were identified in intra-duck variations (p518-L vs p518-S), whereas other changes in HA (N170D), NA (I56T), and NP (Y289H) were present in inter-duck variations (DV518 vs DV413). Both p518-L and p518-S strains had the N170D substitution in HA, which might be related to their greater binding to MDCK cells. Additionally, polymerase activity assays on 293T cells demonstrated the role of vRNP in modulating the replication capability of the duck p518-L viruses in mammalian cells. CONCLUSION: These results demonstrate that intra-host phenotypic variation occurs even within an individual duck. In view of recent human infections by low pathogenic AIVs, this study suggests possible determinants involved in the stepwise selection of virus variants from the duck influenza virus population which may facilitate inter-species transmission.


Assuntos
Patos , Genótipo , Vírus da Influenza A Subtipo H5N2/fisiologia , Influenza Aviária/virologia , Fenótipo , Sequência de Aminoácidos , Substituição de Aminoácidos , Animais , Evolução Biológica , Linhagem Celular , Células Cultivadas , Embrião de Galinha , Variação Genética , Genoma Viral , Humanos , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Taiwan , Ensaio de Placa Viral , Proteínas Virais/química , Proteínas Virais/genética , Replicação Viral
15.
Biomed Res Int ; 2015: 805039, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26290875

RESUMO

Hand, foot, and mouth disease (HFMD) has threatened East Asia for more than three decades and has become an important public health issue owing to its severe sequelae and mortality among children. The lack of effective treatment and vaccine for HFMD highlights the urgent need for efficiently integrated early warning surveillance systems in the region. In this study, we try to integrate the available surveillance and weather data in East Asia to elucidate possible spatiotemporal correlations and weather conditions among different areas from low to high latitude. The general additive model (GAM) was applied to understand the association between HFMD and latitude, as well as meteorological factors for islands in East Asia, namely, Japan, Taiwan, Hong Kong, and Singapore, from 2012 to 2014. The results revealed that latitude was the most important explanatory factor associated with the timing and amplitude of HFMD epidemics (P < 0.0001). Meteorological factors including higher dew point, lower visibility, and lower wind speed were significantly associated with the rise of epidemics (P < 0.01). In summary, weather conditions and geographic location could play some role in affecting HFMD epidemics. Regional integrated surveillance of HFMD in East Asia is needed for mitigating the disease risk.


Assuntos
Monitoramento Epidemiológico , Doença de Mão, Pé e Boca/epidemiologia , Ilhas/epidemiologia , Modelos Biológicos , Animais , Extremo Oriente/epidemiologia , Humanos
17.
Anal Chem ; 87(10): 5410-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25879394

RESUMO

A molecular beacon (MB)-based sensor to offer a decisive answer in combination with information originated from dual-target inputs is designed. The system harnesses an assistant strand and thermodynamically favored designation of unpaired nucleotides (UNs) to process the binary targets in "AND-gate" format and report fluorescence in "off-on" mechanism via a formation of a DNA four-way junction (4WJ). By manipulating composition of the UNs, the dynamic fluorescence difference between the binary targets-coexisting circumstance and any other scenario was maximized. Characteristic equilibrium constant (K), change of entropy (ΔS), and association rate constant (k) between the association ("on") and dissociation ("off") states of the 4WJ were evaluated to understand unfolding behavior of MB in connection to its sensing capability. Favorable MB and UNs were furthermore designed toward analysis of genuine genetic sequences of hemagglutinin (HA) and neuraminidase (NA) in an influenza A H5N2 isolate. The MB-based sensor was demonstrated to yield a linear calibration range from 1.2 to 240 nM and detection limit of 120 pM. Furthermore, high-fidelity subtyping of influenza virus was implemented in a sample of unpurified amplicons. The strategy opens an alternative avenue of MB-based sensors for dual targets toward applications in clinical diagnosis.


Assuntos
Técnicas Biossensoriais/métodos , Vírus da Influenza A Subtipo H5N2/isolamento & purificação , Sondas de Oligonucleotídeos/metabolismo , Vírus da Influenza A Subtipo H5N2/classificação , Vírus da Influenza A Subtipo H5N2/metabolismo , Limite de Detecção , Modelos Moleculares , Conformação de Ácido Nucleico , Desnaturação de Ácido Nucleico , Sondas de Oligonucleotídeos/química , Termodinâmica
18.
Sleep Breath ; 19(3): 809-17, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25450153

RESUMO

PURPOSE: Dyslipidemia is considered as one mechanism causing cardiovascular sequelae in obstructive sleep apnea (OSA). Continuous positive airway pressure (CPAP) can reduce cardiovascular morbidities but its effect on lipid profiles is inconclusive. This study aimed to investigate the effects of CPAP on lipid profiles by a meta-analysis of the existing randomized controlled trials. METHODS: Studies were retrieved from MEDLINE/PubMed, EMBASE, CENTRAL, commercial websites, and article references up to August 2013 following the protocols (PROSPERO CRD42012002636). Randomized controlled trials investigating the CPAP effects on changes in lipid profiles in adult patients with OSA were included. Two independent researchers extracted relevant data in duplicate. The pooled effect was analyzed by fixed-effect generic inverse variance, and the heterogeneity was assessed using the I (2) statistic. RESULTS: Six trials with 348 patients and 351 controls were included. CPAP significantly lowered total cholesterol (mean, -6.23 mg/dl; 95% CI, -8.73 to -3.73; I (2), 0%; p < 0.001), triglyceride (mean, -12.60 mg/dl; 95% CI, -18.80 to -6.41; I (2), 25%; p < 0.001), and high-density lipoprotein (mean, -1.05 mg/dl; 95% CI, -1.69 to -0.40; I (2), 0%; p = 0.001), but not low-density lipoprotein (mean, -1.01 mg/dl; 95% CI, -5.04 to 3.02; I (2), 0%; p = 0.62). The lipid-lowering effects were homogeneous across the studies. By subgroup analysis, the reductions of lipid profiles were associated with the cross-over design, subtherapeutic CPAP as placebo, enrolled patients with moderate-to-severe OSA or daytime sleepiness, and CPAP treatment with short-term duration or good compliance. CONCLUSIONS: This meta-analysis validates the observation that CPAP can reduce lipid profiles in patients with OSA.


Assuntos
Pressão Positiva Contínua nas Vias Aéreas , Lipídeos/sangue , Apneia Obstrutiva do Sono/sangue , Apneia Obstrutiva do Sono/terapia , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Resultado do Tratamento
19.
J Nanosci Nanotechnol ; 15(11): 9158-62, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26726661

RESUMO

A germanium (Ge)-based substrate combined with germanium-tin (GeSn) alloy embedded in source/drain (S/D) regions has attracted significant attention because of its ability to satisfy the requirements of a high-mobility channel. Devices are shrunk in their geometries to meet the target of superior density in layout arrangement. Thus, determining the influences of devices on mobility gain is important. Accordingly, several designed factors, including gate width, S/D length, and Sn concentration of the GeSn stressor, are systematically analyzed in this study. A second-order formula composed of piezoresistance coefficients is derived and adopted to achieve a precise mobility gain estimation. A peak of the carrier mobility gain appears when a nanoscale geometry combination of 20 nm gate length and -200 nm gate width is used in the Ge channel, and 10% of the Sn mole proportion of the GeSn alloy is applied.

20.
Materials (Basel) ; 8(8): 5121-5137, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-28793495

RESUMO

three-dimensional integrated circuit (3D-IC) structure with a significant scale mismatch causes difficulty in analytic model construction. This paper proposes a simulation technique to introduce an equivalent material composed of microbumps and their surrounding wafer level underfill (WLUF). The mechanical properties of this equivalent material, including Young's modulus (E), Poisson's ratio, shear modulus, and coefficient of thermal expansion (CTE), are directly obtained by applying either a tensile load or a constant displacement, and by increasing the temperature during simulations, respectively. Analytic results indicate that at least eight microbumps at the outermost region of the chip stacking structure need to be considered as an accurate stress/strain contour in the concerned region. In addition, a factorial experimental design with analysis of variance is proposed to optimize chip stacking structure reliability with four factors: chip thickness, substrate thickness, CTE, and E-value. Analytic results show that the most significant factor is CTE of WLUF. This factor affects microbump reliability and structural warpage under a temperature cycling load and high-temperature bonding process. WLUF with low CTE and high E-value are recommended to enhance the assembly reliability of the 3D-IC architecture.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA