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2.
Opt Express ; 29(14): 22567-22577, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34266016

RESUMO

Photoacoustic laser streaming provides a versatile technique to manipulate liquids and their suspended objects with light. However, only gold was used in the initial demonstrations. In this work, we first demonstrate that laser streaming can be achieved with common non-plasmonic metals such as Fe and W by their ion implantations in transparent substrates. We then investigate the effects of ion dose, substrate material and thickness on the strength and duration of streaming. Finally, we vary laser pulse width, repetition rate and power to understand the observed threshold power for laser streaming. It is found that substrate thickness has a negligible effect on laser streaming down to 0.1 mm, glass and quartz produce much stronger streaming than sapphire because of their smaller thermal conductivity, while quartz exhibits the longest durability than glass and sapphire under the same laser intensity. Compared with Au, Fe and W with higher melting points show a longer lifetime although they require a higher laser intensity to achieve a similar speed of streaming. To generate a continuous laser streaming, the laser must have a minimum pulse repetition rate of 10 Hz and meet the minimum pulse width and energy to generate a transient vapor layer. This vapor layer enhances the generation of ultrasound waves, which are required for observable fluid jets. Principles of laser streaming and temperature simulation are used to explain these observations, and our study paves the way for further materials engineering and device design for strong and durable laser streaming.

3.
Curr Microbiol ; 77(2): 194-203, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31776652

RESUMO

A study of the induced effect of different types of weak magnetic field exposure on bacterial growth is performed, comparing the relative changes after removal from the magnetic fields. This investigation is relevant to understand the effect of magnetic field exposure on human beings due to electronic devices. For this purpose, we use four species of common bacteria in reference to human health and safety including Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Pseudomonas aeruginosa. The choice of these four bacteria also allows us to check for effects which rely upon the Gram-staining properties or shapes of bacterial species. These species were initially exposed to static, non-homogeneous, and alternating weak magnetic fields, and then they were grown in incubators in the same environment at 37 °C simultaneously. Comparative measurements of optical density are then used to track the sustained impact on bacterial growth in the experimental samples. Bacteria were first grown in different weak magnetic fields on a plain glass surface both in liquid and solid media. Magnetic field-treated bacteria were then transferred into similar test tubes to grow in an incubator concurrently. Bacterial cultures in liquid nutrient broth on plain glass proliferated faster in most species. Different magnetic fields affect the growth pattern of bacteria differently, depending on the bacterial strain. The weak magnetic field seems to decelerate the growth rate, even after the magnetic field is removed. With application of this study, we can potentially investigate the effect of weak field exposures on Eukaryotic cells and gene dynamics.


Assuntos
Bactérias/crescimento & desenvolvimento , Aderência Bacteriana , Campos Magnéticos , Escherichia coli/crescimento & desenvolvimento , Vidro , Pseudomonas aeruginosa/crescimento & desenvolvimento , Staphylococcus aureus/crescimento & desenvolvimento , Staphylococcus epidermidis/crescimento & desenvolvimento
4.
Proc Natl Acad Sci U S A ; 116(14): 6580-6585, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30872482

RESUMO

Enabled initially by the development of microelectromechanical systems, current microfluidic pumps still require advanced microfabrication techniques to create a variety of fluid-driving mechanisms. Here we report a generation of micropumps that involve no moving parts and microstructures. This micropump is based on a principle of photoacoustic laser streaming and is simply made of an Au-implanted plasmonic quartz plate. Under a pulsed laser excitation, any point on the plate can generate a directional long-lasting ultrasound wave which drives the fluid via acoustic streaming. Manipulating and programming laser beams can easily create a single pump, a moving pump, and multiple pumps. The underlying pumping mechanism of photoacoustic streaming is verified by high-speed imaging of the fluid motion after a single laser pulse. As many light-absorbing materials have been identified for efficient photoacoustic generation, photoacoustic micropumps can have diversity in their implementation. These laser-driven fabrication-free micropumps open up a generation of pumping technology and opportunities for easy integration and versatile microfluidic applications.

5.
Microbiologyopen ; 8(2): e00640, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-29799166

RESUMO

This research project has major applications in the healthcare and biomedical industries. Bacteria reside in human bodies and play an integral role in the mechanism of life. However, their excessive growth or the invasion of similar agents can be dangerous and may cause fatal or incurable diseases. On the other hand, increased exposure to electromagnetic radiation and its impact on health and safety is a common concern to medical science. Some nanostructure materials have interesting properties regarding facilitating or impeding cell growth. An understanding of these phenomena can be utilized to establish the optimum benefit of these structures in healthcare and medical research. We focus on the commonly found rod-shaped, gram-negative bacteria and their orientation and community development on the cellular level in the presence of weak magnetic fields on one dimensional nano-ripple glass patterns to investigate the impact of nanostructures on the growth pattern of bacteria. The change in bacterial behavior on nanostructures and the impact of magnetic fields will open up new venues in the utilization of nanostructures. It is noticed that bacterial entrapment in nano-grooves leads to the growth of larger colonies on the nanostructures, whereas magnetic fields reduce the size of colonies and suppress their growth.


Assuntos
Aderência Bacteriana , Escherichia coli/fisiologia , Escherichia coli/efeitos da radiação , Campos Magnéticos , Nanoestruturas , Pseudomonas aeruginosa/fisiologia , Pseudomonas aeruginosa/efeitos da radiação , Vidro , Propriedades de Superfície
6.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-702210

RESUMO

Objective To compare the efficacy of surgical treatment(ST) and mechanical ventilation treatment(MVT) for flail chest.Methods From March 2013 to May 2017,81 patients with flail chest who underwent ST(28 cases) and MVT(53 cases) were enrolled in ICU.The relevant indicators of efficacy were compared including mechanical ventilation (MV) time,bed rest time,oxygen administration time,catheterization time,antibiotic use time,drug analgesia,drug analgesia patients,proportion of stop/postoperative sputum alone,ICU treatment time,hospital stay,mortality,readmission within two months and long-term pulmonary function after discharge.Results The MV time,bed time,oxygen time,antibiotic use time,ICU treatment time and hospitalization time of MVT were longer than those of ST group,the differences were significant(P < 0.05).MVT had more analgesic times,more analgesic cases,smaller proportion of offline/postoperative sputum along and less hospitalization fees compared with ST group,the differences were significant(P <0.05).There was no significant difference in the main indexes of pulmonary function between two groups in 3 months after discharge.Conclusion ST and MVT respectively has advantages and disadvantages for flail chest.There is no significant difference in long-term pulmonary function of ST and MVT.While MVT has less trauma and lower cost.The appropriate treatment could be selected according to the clinical situation.

7.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-702208

RESUMO

Objective To evaluate the surgical efficacy of end-to-end layered anastomosis for patients with esophagogastrostomy after esophagectomy.Methods Selected 35 patients who received end-to-end layered anastomosis in esophagogastrostomy after esophagectomy in people' s hospital of Meishan from January 2016 to February 2017 as end-to-end group,while 21 patients with end-to-side layered anastomosis in esophagogastrostomy after esophagectomy as end-to-side group.The anastomosis time,anastomosis tension,oppression degree,fistula incidence,acid reflux incidence,belching incidence and obstruction incidence between two groups were compared.Results The average anastomosis time was (25.17 ± 5.15)minutes in end-to-end group,and (26.10 ± 5.30)minutes in end-to-side group,the difference was not significant (P > 0.05).The anastomosis tension of end-to-end group,without oppression,was mostly smaller than that of end-to-side group.There were no case of anastomotic fistula in end-to-end group and 2 cases(14.29%) of anastomotic fistula in end-to-side group,the difference was not significant (P > 0.05).There were no case of obstruction in end-to-end group and 4 cases (19.05%) of obstruction in end-to-side group,the difference was significant (P =0.016).There was no significant difference in acid reflux and belching between the two groups (P > 0.05) in perioperative period and 6 months after surgery.There was no delayed anastomotic fistula and anastomotic stenosis needing expansion in 6 months after surgery.Conclusion Without causing more adverse reactions,end-to-end layered anastomosis in esophagogastrostomy after esophagectomy can avoid the incision that may affect the blood supply of esophagus and stomach,and avoid the pressure from esophagus and stomach.

8.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-806269

RESUMO

Objective@#To explore drug resistance of different viral loads, and investigate the relationship between drug resistance and CD4+T cell counts in patients with HIV antiretroviral therapy (ART) in China from 2003 to 2015.@*Methods@#Data were extracted from the Chinese National HIVDR Surveillance database from 2003 to 2015. For this study, the data collected were as follows: having received ART for ≥12 months; 18 years or older; demographic characteristics, information of ART, CD4+T cell counts, viral load (VL) and HIV drug resistance of a total of 8 362 patients were collected. Multi-variables non-conditional logistic regression model was used to study the relationship between viral load, HIV drug resistance and CD4+T cell counts.@*Results@#Participants with age of (41.8±10.5) years were enrolled in this study. Among them, 59.9% (5 009 cases) were men. The percentage of CD4+T cell counts <200 cells/μl in the total population was 17.9% (1 496 cases), the highest was in VL ≥1 000 copies/ml with drug resistance, which was 43.0% (397/923) , followed by VL 50-999 copies/ml with drug resistance, which was 31.1% (69/222), and the lowest was in VL 50-999 copies/ml without drug resistance 13.2% (273/2 068). Compared to VL 50-999 copies/ml without drug resistance, VL<50 copies/ml, VL 50-999 with drug resistance, VL≥1 000 copies/ml without drug resistance, and VL ≥1 000 copies/ml with drug resistance, the OR (95%CI) of CD4 <200 cells/μl were 0.9 (0.7-1.0), 3.2 (2.3-4.4), 2.6 (2.1-3.2), and 4.9 (4.0-5.9), respectively. Among 222 patients with VL 50-999 and HIVDR, the most frequent antiretroviral drugs were EFV and NVP, both of which were NNRTI, and whose percentage both were 94.1% (209 cases). The most frequent mutations were M184V/I (NNRTI), and the percentage was 26.1% (58 cases). The second one was K103N (NNRTI), and the percentage was 22.5% (50 cases). The percentage of V32L/E (PI) and V82A (PI) were lower, they were 0.9% (2 cases) and 0.5% (1 case) respectively.@*Conclusion@#Decreased CD4+T cell counts were associated with HIV drug resistance at low viraemia. In the case of low viral load, the most vulnerable were the NNRTI antiviral drugs such as EFV and NVP.

9.
Materials (Basel) ; 10(9)2017 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-28885577

RESUMO

In this study, we used a 30 keV argon cluster ion beam bombardment to investigate the dynamic processes during nano-ripple formation on gold surfaces. Atomic force microscope analysis shows that the gold surface has maximum roughness at an incident angle of 60° from the surface normal; moreover, at this angle, and for an applied fluence of 3 × 1016 clusters/cm², the aspect ratio of the nano-ripple pattern is in the range of ~50%. Rutherford backscattering spectrometry analysis reveals a formation of a surface gradient due to prolonged gas cluster ion bombardment, although the surface roughness remains consistent throughout the bombarded surface area. As a result, significant mass redistribution is triggered by gas cluster ion beam bombardment at room temperature. Where mass redistribution is responsible for nano-ripple formation, the surface erosion process refines the formed nano-ripple structures.

10.
Mater Sci Eng C Mater Biol Appl ; 60: 151-155, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26706518

RESUMO

In this report, the effects of argon (Ar) ion irradiation on poly(lactic acid-co-glycolic acid) (PLGA) substrates on biocompatibility were studied. PLGA scaffold substrates were prepared by spin coating glass surfaces with PLGA dissolved in anhydrous chloroform. Previously, we showed that surface modifications of PLGA films using ion irradiation modulate the inherent hydrophobicity of PLGA surface. Here we show that with increasing ion dose (1×10(12) to 1×10(14) ions/cm(2)), hydrophobicity and surface roughness decreased. Biocompatibility for NIH3T3 mouse fibroblast cells was increased by argon irradiation of PLGA substrates. On unirradiated PLGA films, fibroblasts had a longer doubling time and cell densities were 52% lower than controls after 48 h in vitro. Argon irradiated PLGA substrates supported growth rates similar to control. Despite differences in cell cycle kinetics, there was no detectible cytotoxicity observed on any substrate. This demonstrates that argon ion irradiation can be used to tune the surface microstructure and generate substrates that are more compatible for the cell growth and proliferation.


Assuntos
Argônio/química , Ácido Láctico/química , Nanocompostos/química , Ácido Poliglicólico/química , Polímeros/química , Animais , Argônio/farmacologia , Proliferação de Células/efeitos dos fármacos , Camundongos , Células NIH 3T3 , Poliésteres
11.
Clin Drug Investig ; 35(9): 583-91, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26293521

RESUMO

BACKGROUND AND OBJECTIVE: The polymorphic enzyme P450 oxidoreductase (POR) transfers electrons from nicotinamide adenine dinucleotide phosphate (NADPH) to cytochrome P450 (CYP) 3A enzyme s, which metabolize atorvastatin. This suggests that variations in the CYP3A5 and POR genes may influence the response to statins. We aimed to investigate the association and interactions between CYP3A5*3 and POR*28 polymorphisms and the lipid-lowering effects of atorvastatin in a Chinese population. METHODS: Genotypes were determined by polymerase chain reaction (PCR) with restriction fragment length polymorphism analysis and by PCR with direct sequencing analysis for 179 hyperlipidaemic patients treated with atorvastatin 20 mg once daily for 4 weeks. Serum levels of triglycerides (TGs), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) were determined before and after treatment. RESULTS: For the 179 patients (including 100 males), the variant allele frequencies of CYP3A5*3 and POR*28 were 73.75 and 41.62 %, respectively. Among all patients, no significant association was found between CYP3A5*3 polymorphisms and TG, TC, LDL-C and HDL-C levels before and after treatment with 20 mg of atorvastatin daily for 4 weeks. Homozygotes for the POR*28 T allele showed a significantly lower mean concentration of LDL-C than homozygotes for the POR*28 C allele (POR*28 TT vs POR*28 CC: 2.46 ± 0.37 vs 2.69 ± 0.49 mmol/L, P = 0.019) after treatment with atorvastatin 20 mg daily for 4 weeks. After adjustment for age, sex and body mass index, CYP3A5 non-expressors who were POR*28 wild-type homozygotes showed significantly higher mean TC and LDL-C levels than those who were POR*28 variant homozygotes, both at baseline (*3/CC vs *3/TT; TC: 7.30 ± 0.73 vs 6.94 ± 0.36 mmol/L, P = 0.026; LDL-C: 3.88 ± 0.70 vs 3.47 ± 0.46 mmol/L, P = 0.009) and after atorvastatin treatment (*3/CC vs *3/TT; TC: 6.03 ± 0.64 vs 5.69 ± 0.34 mmol/L, P = 0.017; LDL-C: 2.80 ± 0.62 vs 2.43 ± 0.40 mmol/L, P = 0.008). CYP3A5 non-expressors who were POR*28 wild-type homozygotes showed significantly higher TC and LDL-C levels at baseline (*3/CC vs *1/CC; TC: 7.30 ± 0.73 vs 6.95 ± 0.41 mmol/L, P = 0.010; LDL-C: 3.88 ± 0.70 vs 3.55 ± 0.39 mmol/L, P = 0.010) and showed higher TC levels after atorvastatin treatment (*3/CC vs *1/CC; 6.03 ± 0.64 vs 5.73 ± 0.27 mmol/L, P = 0.012), in comparison with patients expressing CYP3A5 who were POR*28 wild-type homozygotes. CYP3A5 non-expressors who were POR*28 heterozygotes showed significantly lower percentage changes in TC from baseline than those expressing CYP3A5 who were POR*28 heterozygotes (*3/CT vs *1/CT; 16.77 ± 3.13 vs 18.40 ± 4.16 mmol/L, P = 0.031). CONCLUSION: POR*28 is associated with a poorer response to atorvastatin, but there is no association of the latter with CYP3A5*3. POR*28 single nucleotide polymorphisms are associated with greater increases in the effect on plasma lipids in non-expressors of CYP3A5. Besides CYP3A5*3 genetic polymorphism, POR*28 genetic polymorphism might also be responsible for the marked interindividual variability in the lipid-lowering response to atorvastatin.


Assuntos
Atorvastatina/farmacologia , Citocromo P-450 CYP3A/genética , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Lipídeos/sangue , Povo Asiático/genética , Feminino , Frequência do Gene , Genótipo , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estudos Prospectivos
12.
ACS Appl Mater Interfaces ; 7(21): 11155-64, 2015 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-25941752

RESUMO

Phosphoproteomic analysis offers a unique view of cellular function and regulation in biological systems by providing global measures of a key cellular regulator in the form of protein phosphorylation. Understanding the phosphorylation changes between normal and diseased cells or tissues offers a window into the mechanism of disease and thus potential targets for therapeutic intervention. A key step in these studies is the enrichment of phosphorylated peptides that are typically separated and analyzed by using liquid chromatography mass spectrometry. The mesoporous titania beads/particles (e.g., Titansphere TiO2 beads from GL Sciences Inc., Japan) that are widely used for phosphopeptide enrichment are expensive and offer very limited opportunities for further performance improvement. Titiania nanotube arrays have shown promising characteristics for phosphopeptide separation. Here we report a proof-of-concept study to evaluate the efficacy of nanotubes on Ti-wire for phosphoproteomics research. We used titania nanotubes radially grown on titanium wires as well as the commercial beads to separate phosphopeptides generated from mouse liver complex tissue extracts. Our studies revealed that the nanotubes on metal wire provide comparable efficacy for enrichment of phophopeptides and offer an ease of use advantage versus mesoporous beads, thus having the potential to become a low cost and more practical material/methodology for phosphopeptide enrichment in biological studies.


Assuntos
Cromatografia/métodos , Nanopartículas Metálicas/química , Nanotubos/química , Fosfopeptídeos/isolamento & purificação , Titânio/química , Nanopartículas Metálicas/ultraestrutura , Conformação Molecular , Nanotubos/ultraestrutura , Nanofios/química , Nanofios/ultraestrutura , Fosfopeptídeos/química
13.
Journal of Practical Radiology ; (12): 929-932,941, 2015.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-600262

RESUMO

Objective To investigate the value of diffusion weighted imaging (DWI)in identification of different molecular sub-types for breast cancer classifications.Methods All patients with breast cancer were divided into four subtypes groups by immuno-histochemistry results including Luminal A subtype,Luminal B subtype,HER2-over expressing (HER2-OE)subtype,and triple negative breast cancer (TNBC),respectively.The means of maximum,average,and minimum ADC of the lesions in all patients were recorded.The analysis of ANOVA and least significant difference test (LSD-t )were used for the statistical evaluation.Results There were significant differences in maximum ADC,average ADC,and minimum ADC among Luminal A subtype (n=21),Lu-minal B subtype (n=22),HER2-OE subtype (n=1 7)and TNBC subtype (n=12)groups (P =0.025,0.039 and 0.041,respec-tively).However,paired comparison in mean of maximum ADC,average ADC and minimum ADC by LSD-t multiple comparisons among Luminal A,Luminal B,HER2-OE and TNBC respectively were not significantly different.Conclusion DWI may be difficult to discriminate the molecular subtypes of breast cancer classification before surgery or biopsy.

14.
J Chem Phys ; 139(17): 174317, 2013 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-24206308

RESUMO

We investigated the dynamics of the reaction of (3)P atomic carbon with propene (C3H6) at reactant collision energy 3.8 kcal mol(-1) in a crossed molecular-beam apparatus using synchrotron vacuum-ultraviolet ionization. Products C4H5, C4H4, C3H3, and CH3 were observed and attributed to exit channels C4H5 + H, C4H4 + 2H, and C3H3 + CH3; their translational-energy distributions and angular distributions were derived from the measurements of product time-of-flight spectra. Following the addition of a (3)P carbon atom to the C=C bond of propene, cyclic complex c-H2C(C)CHCH3 undergoes two separate stereoisomerization mechanisms to form intermediates E- and Z-H2CCCHCH3. Both the isomers of H2CCCHCH3 in turns decompose to C4H5 + H and C3H3 + CH3. A portion of C4H5 that has enough internal energy further decomposes to C4H4 + H. The three exit channels C4H5 + H, C4H4 + 2H, and C3H3 + CH3 have average translational energy releases 13.5, 3.2, and 15.2 kcal mol(-1), respectively, corresponding to fractions 0.26, 0.41, and 0.26 of available energy deposited to the translational degrees of freedom. The H-loss and 2H-loss channels have nearly isotropic angular distributions with a slight preference at the forward direction particularly for the 2H-loss channel. In contrast, the CH3-loss channel has a forward and backward peaked angular distribution with an enhancement at the forward direction. Comparisons with reactions of (3)P carbon atoms with ethene, vinyl fluoride, and vinyl chloride are stated.

15.
J Chem Phys ; 139(13): 134301, 2013 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-24116562

RESUMO

The dynamics of the C((3)P) + C2H3Cl reaction at collision energy 3.8 kcal mol(-1) was investigated in a crossed molecular-beam apparatus using synchrotron vacuum-ultraviolet ionization. Time-of-flight spectra of products C3H2Cl, C3H3, and Cl were recorded at various laboratory scattering angles, from which translational-energy distributions and angular distributions of product channels C3H2Cl + H and C3H3 + Cl were derived. Cl correlates satisfactorily with C3H3 in linear momentum and angular distributions, which confirms the production of C3H3 + Cl. The H-loss (Cl-loss) channel has average translational-energy release 14.3 (8.8) kcal mol(-1) corresponding to a fraction 0.30 (0.14) of available energy into the translational degrees of freedom of product HCCCHCl + H (H2CCCH + Cl). The branching ratio of channel H to channel Cl was determined approximately as 12:88. The measurements of translational-energy releases and photoionization thresholds cannot distinguish HCCCHCl from H2CCCCl because both isomers have similar enthalpy of formation and ionization energy; nevertheless, the Rice-Ramsperger-Kassel-Marcus calculation prefers HCCCHCl. The measurement of photoionization spectra identifies product C3H3 as H2CCCH (propargyl). Both products C3H2Cl + H and C3H3 + Cl might correlate to the same triplet intermediate H2CCCHCl but have distinct angular distributions; the former is nearly isotropic whereas the latter is forward biased. A comparison with the C((3)P) + C2H3F reaction is stated.

16.
J Chem Phys ; 139(6): 064311, 2013 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-23947859

RESUMO

Two product channels C3H2F + H and C3H3 + F were identified in the reaction of C((3)P) atoms with vinyl fluoride (C2H3F) at collision energy 3.7 kcal mol(-1) in a crossed molecular-beam apparatus using selective photoionization. Time-of-flight (TOF) spectra of products C3H2F and C3H3 were measured at 12-16 laboratory angles as well as a TOF spectrum of atomic F, a counter part of C3H3, was recorded at single laboratory angle. From the best simulation of product TOF spectra, translational-energy distributions at seven scattering angles and a nearly isotropic (forward and backward peaked) angular distribution were derivable for exit channel C3H2F + H (C3H3 + F) that has average kinetic-energy release of 14.5 (4.9) kcal mol(-1). Products C3H2F + H and C3H3 + F were estimated to have a branching ratio of ~53:47. Furthermore, TOF spectra and photoionization spectra of products C3H2F and C3H3 were measured at laboratory angle 62° with photoionization energy ranging from 7 eV to 11.6 eV. The appearance of TOF spectra is insensitive to photon energy, implying that only single species overwhelmingly contributes to products C3H2F and C3H3. HCCCHF (H2CCCH) was identified as the dominant species based on the measured ionization threshold of 8.3 ± 0.2 (8.6 ± 0.2) eV and the maximal translational-energy release. The C/H and C/F exchange mechanisms are stated.

17.
J Phys Chem B ; 117(16): 4332-9, 2013 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-23140194

RESUMO

The mechanism responsible for the redox reaction of [Co(III)(en)3]Ac3 to Co(II) complex has been determined to be intramolecular electron transfer. It was measured in real time by means of subpicosecond extended X-ray absorption fine structure spectra, EXAFS, and optical experiments and supported by density functional theory calculations. The proposed mechanism is based on histograms of bond length changes of the transient structures measured as a function of time, with subpicosecond time and sub-Angstrom resolution and femtosecond transient spectra and kinetics after excitation with a 267 nm femtosecond pulse. Even though four Fe and Co complexes were excited in the charge transfer band and the photoinduced redox reaction proceeds with similar high redox quantum yield, the dominant electron operating mechanism differs: intramolecular for amine metal complexes and intermolecular for oxalate metal complexes. The ligand orientation degree of freedom and counterion effect are proposed to provide tentative explanation for the electron transfer mechanism.


Assuntos
Compostos Organometálicos/química , Cobalto/química , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Transporte de Elétrons , Compostos Férricos/química , Cinética , Oxirredução , Fatores de Tempo , Espectroscopia por Absorção de Raios X
18.
Artigo em Chinês | WPRIM (Pacífico Ocidental) | ID: wpr-246268

RESUMO

<p><b>OBJECTIVE</b>To observe the long-term efficacy and safety of warm needling therapy combined with rehabilitation training in the treatment of knee osteoarthritis (KOA) for the patients living in simple room after earthquake.</p><p><b>METHODS</b>Eighty-eight cases of KOA were randomized into a warm needling group and an acupuncture group, 44 cases in each one. In the warm needling group, the warm needling therapy was applied at Neixiyan (EX LE 4) and Dubi (ST 35), in combination with rehabilitation training. In the acupuncture group, the same rehabilitation training was received, and the same acupoints were selected as the warm needling group, but only stimulated with acupuncture without moxibustion applied. The clinical efficacy was observed after 20 treatments and in 1-2 months of follow-up.</p><p><b>RESULTS</b>The total effective rate was 100.0% (41/41) in the warm needling group, which was apparently superior to 85.4% (35/41) in the acupuncture group (P < 0.05). The symptom integral, pain and knee joint function score were all improved significantly after 20 treatments in both groups (all P < 0.05). The improvements in symptoms and pain in the warm needling group were superior apparently to the acupuncture group (all P < 0.05). The efficacy remained well within 2 months follow-up (all P < 0.05). But the difference in knee joint function score was not statistically significant between the two groups (all P > 0.05).</p><p><b>CONCLUSION</b>The combined therapy of warm needling and rehabilitation training achieves the superior efficacy and good safety in the treatment of KOA as compared with the combined therapy of simple acupuncture and rehabilitation training for the patients living in simple room after earthquake.</p>


Assuntos
Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pontos de Acupuntura , Terapia por Acupuntura , Articulação do Joelho , Osteoartrite do Joelho , Reabilitação , Terapêutica , Resultado do Tratamento
19.
J Phys Chem A ; 116(29): 7615-22, 2012 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-22747441

RESUMO

We investigated the title reaction at collision energy 3.5 kcal mol(-1) in a crossed molecular beam apparatus using undulator radiation as an ionization source. Time-of-flight (TOF) spectra of product C(3)H(3) were measured in laboratory angles from 20° to 100° using two photoionization energies 9.5 and 11.6 eV. These two sets of experimental data exhibit almost the same TOF distributions and laboratory angular distributions. From the best simulation, seven angle-specific kinetic-energy distributions and a nearly isotropic angular distribution are derived for product channel C(3)H(3) + H that has an average kinetic-energy release of 15.5 kcal mol(-1), corresponding to an average internal energy of 33.3 kcal mol(-1) in C(3)H(3). Furthermore, TOF spectra of product C(3)H(3) were measured at laboratory angle 52° with ionizing photon energies from 7 to 12 eV. The appearance of TOF spectra remains almost the same, indicating that a species exclusively contributes to product C(3)H(3); the species is identified as H(2)CCCH (propargyl) based on the ionization energy of 8.6 ± 0.2 eV and the maximal kinetic-energy release of 49 kcal mol(-1). Theoretical calculations indicate that the rapid inversion mechanism and rotation in intermediate H(2)CCCH(2) can result in a forward-backward symmetric angular distribution for product C(3)H(3) + H. The present work avoids the interference of reactions of C((1)D) and C(2) radicals with C(2)H(4) and rules out the probability of production of other isomers like c-C(3)H(3) and H(3)CCC proposed in the previous work at least at the investigated collision energy.

20.
Proc Natl Acad Sci U S A ; 108(47): 18887-92, 2011 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-22065752

RESUMO

We utilize 100 fs optical pulses to induce ultrafast disorder of 35- to 150-nm thick single Au(111) crystals and observe the subsequent structural evolution using 0.6-ps, 8.04-keV X-ray pulses. Monitoring the picosecond time-dependent modulation of the X-ray diffraction intensity, width, and shift, we have measured directly electron/phonon coupling, phonon/lattice interaction, and a histogram of the lattice disorder evolution, such as lattice breath due to a pressure wave propagating at sonic velocity, lattice melting, and recrystallization, including mosaic formation. Results of theoretical simulations agree and support the experimental data of the lattice/liquid phase transition process. These time-resolved X-ray diffraction data provide a detailed description of all the significant processes induced by ultrafast laser pulses impinging on thin metallic single crystals.


Assuntos
Ouro/química , Temperatura Alta , Lasers , Nanoestruturas/química , Transição de Fase , Difração de Raios X/métodos , Simulação por Computador , Cristalização , Elétrons , Modelos Químicos , Fônons , Fatores de Tempo
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