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1.
J Chem Phys ; 147(7): 074101, 2017 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-28830158

RESUMEN

This work treats the impact of vibrational coherence on the quantum efficiency of a dissipative electronic wave packet in the vicinity of a conical intersection by monitoring the time-dependent wave packet projection onto the tuning and the coupling mode. The vibrational coherence of the wave packet is tuned by varying the strength of the dissipative vibrational coupling of the tuning and the coupling modes to their thermal baths. We observe that the most coherent wave packet yields a quantum efficiency of 93%, but with a large transfer time constant. The quantum yield is dramatically decreased to 50% for a strongly damped incoherent wave packet, but the associated transfer time of the strongly localized wave packet is short. In addition, we find for the strongly damped wave packet that the transfer occurs via tunneling of the wave packet between the potential energy surfaces before the seam of the conical intersection is reached and a direct passage takes over. Our results provide direct evidence that vibrational coherence of the electronic wave packet is a decisive factor which determines the dynamical behavior of a wave packet in the vicinity of the conical intersection.

2.
Phys Chem Chem Phys ; 17(5): 3131-41, 2015 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-25515705

RESUMEN

Proposed in theory and then their existence confirmed, anion-π interactions have been recognized as new and important non-covalent binding forces. Despite extensive theoretical studies, numerous crystal structural identifications, and a plethora of solution phase investigations, anion-π interaction strengths that are free from complications of condensed-phase environments have not been directly measured in the gas phase. Herein we present a joint photoelectron spectroscopic and theoretical study on this subject, in which tetraoxacalix[2]arene[2]triazine 1, an electron-deficient and cavity self-tunable macrocyclic, was used as a charge-neutral molecular host to probe its interactions with a series of anions with distinctly different shapes and charge states (spherical halides Cl(-), Br(-), I(-), linear thiocyanate SCN(-), trigonal planar nitrate NO3(-), pyramidic iodate IO3(-), and tetrahedral sulfate SO4(2-)). The binding energies of the resultant gaseous 1 : 1 complexes (1·Cl(-), 1·Br(-), 1·I(-), 1·SCN(-), 1·NO3(-), 1·IO3(-) and 1·SO4(2-)) were directly measured experimentally, exhibiting substantial non-covalent interactions with pronounced anion-specific effects. The binding strengths of Cl(-), NO3(-), IO3(-) with 1 are found to be strongest among all singly charged anions, amounting to ca. 30 kcal mol(-1), but only about 40% of that between 1 and SO4(2-). Quantum chemical calculations reveal that all the anions reside in the center of the cavity of 1 with an anion-π binding motif in the complexes' optimized structures, where 1 is seen to be able to self-regulate its cavity structure to accommodate anions of different geometries and three-dimensional shapes. Electron density surface and charge distribution analyses further support anion-π binding formation. The calculated binding energies of the anions and 1 nicely reproduce the experimentally estimated electron binding energy increase. This work illustrates that size-selective photoelectron spectroscopy combined with theoretical calculations represents a powerful technique to probe anion-π interactions and has potential to provide quantitative guest-host molecular binding strengths and unravel fundamental insights in specific anion recognitions.

3.
J Phys Chem A ; 119(24): 6244-51, 2015 Jun 18.
Artículo en Inglés | MEDLINE | ID: mdl-25976548

RESUMEN

The oxidation power of permanganates (MnO4(-)) is known to be strongly dependent on pH values, and is greatly enhanced in acidic solutions, in which, for example, MnO4(-) can even oxidize Cl(-) ions to produce Cl2 molecules. Although such dependence has been ascribed due to the different reduced states of Mn affordable in different pH media, a molecular level understanding and characterization of initial redox pair complexes available in different pH solutions is very limited. Herein, we report a comparative study of [MnO4](-) and [MnO4·Sol](-) (Sol = H2O, KCl, and HCl) anion clusters by negative ion photoelectron spectroscopy (NIPES) and theoretical computations to probe chemical bonding and electronic structures of [MnO4·Sol](-) clusters, aimed to obtain a microscopic understanding of how MnO4(-) interacts with surrounding molecules. Our study shows that H2O behaves as a solvent molecule, KCl is a spectator bound by pure electrostatic interactions, both of which do not influence the MnO4(-) identity in their respective clusters. In contrast, in [MnO4·HCl](-), the proton is found to interact with both MnO4(-) and Cl(-) with appreciable covalent characters, and the frontier MOs of the cluster are comprised of contributions from both MnO4(-) and Cl(-) moieties. Therefore, the proton serves as a chemical bridge, bringing two negatively charged redox species together to form an intimate redox pair. By adding more H(+) to MnO4(-), the oxygen atom can be taken away in the form of a water molecule, leaving MnO4(-) as an electron deficient MnO3(+) species, which can subsequently oxidize Cl(-) ions.

4.
BMC Neurol ; 14: 194, 2014 Oct 02.
Artículo en Inglés | MEDLINE | ID: mdl-25269594

RESUMEN

BACKGROUND: Some recent studies suggest that some imaging-negative temporal lobe epilepsy (TLE) had significant amygdala enlargement (AE). Contradictory data were also reported in previous studies regarding the association between AE and TLE. The present study was to investigate the clinical characters of a group of TLE with AE and compare the amygdala volume of the same patient before and after antiepileptic drugs treatment by a larger sample size. METHODS: This study recruited 33 mesial TLE patients with AE and 35 healthy volunteers. The clinical history, seizure semiology, electroencephalogram (EEG), fluorodeoxyglucose-positron emission tomography (FDG-PET) and amygdala volume were investigated. The amygdala volume were compared between ipsilateral and contralateral sides, TLE patients and 35 healthy controls, and patients at first and follow-up visit by 3.0 T MRI. RESULTS: Average seizure onset age was 42.0 years (SD 14.3). All patients had complex partial seizures, fourteen had occasional generalized tonic-clonic seizures which often happened during sleep. Ninety percent patients suffered from anxiety or depression. Thirty percent patients had memory decline. Interictal epileptiform discharges appeared predominantly in the anterior or inferior temporal area ipsilateral to AE. Interictal FDG-PET showed regional glucose hypometabolism in the ipsilateral temporal lobe. No hippocampal sclerosis (HS) was suspected in all patients. 22 patients demonstrated good seizure control and significantly reduced volume of the enlarged amygdala after treatment (P < 0.01). The other 11 patients showed initial response to treatment, followed by a gradual increase in seizure frequency over time, and no volume change of the enlarged amygdala after treatment. CONCLUSIONS: TLE with AE probably represents a distinct nosological and probably less homogeneous syndrome which is most likely a subtype of TLE without ipsilateral HS. The chronic and long lasting inflammatory processes or focal cortical dysplasia could lead to amygdala enlargement possibly.


Asunto(s)
Amígdala del Cerebelo/patología , Epilepsia del Lóbulo Temporal/patología , Adulto , Anciano , Epilepsia del Lóbulo Temporal/clasificación , Epilepsia del Lóbulo Temporal/fisiopatología , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Adulto Joven
5.
J Phys Chem A ; 118(37): 8074-80, 2014 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-24261868

RESUMEN

Molecular species with electron affinities (EAs) larger than that of the chlorine atom (3.6131 eV) are superhalogens. The corresponding negative ions, namely, superhalogen anions, are intrinsically very stable with high electron binding energies (EBEs) and widely exist as building blocks of bulk materials and ionic liquids. The most common superhalogen anions proposed and experimentally confirmed to date are either ionic salts or compact inorganic species. Herein, we report a new class of superhalogen species, a series of tetracoordinated organoboron anions [BL4](-) (L = phenyl (1), 4-fluorophenyl (2), 1-imidazolyl (3), L4 = H(pyrazolyl)3 (4)) with bulky organic ligands covalently bound to the central B atom. Negative ion photoelectron spectroscopy (NIPES) reveals that all of these anions possess EBEs higher than that of Cl(-) with the adiabatic/vertical detachment energy (ADE/VDE) of 4.44/4.8 (1), 4.78/5.2 (2), 5.08/5.4 (3), and 4.59/4.9 eV (4), respectively. First-principles calculations confirmed high EBEs of [BL4](-) and predicted that these anions are thermodynamically stable against fragmentation. The unraveled superhalogen nature of these species provides a molecular basis to explain the wide-ranging applications of tetraphenylborate (TPB) (1) and trispyrazolylborate (Tp) (4) in many areas spanning from industrial waste treatment to soft material synthesis and organometallic chemistry.

6.
Inorg Chem ; 50(10): 4493-502, 2011 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-21476536

RESUMEN

Treatment of [Et(4)N][Tp*WS(3)] (1) (Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate) with 2 equiv of AgSCN in MeCN afforded a novel neutral compound [(Tp*WS(2))(2)(µ-S(2))] (2). Reactions of 2 with excess CuX (X = Cl, Br, I) in MeCN and CH(2)Cl(2) or CHCl(3) formed three neutral W/Cu/S clusters [{Tp*W(µ(3)-S)(3)Cu(3)(µ-Cl)}(2)Cu(µ-Cl)(2)(µ(7)-Cl)(MeCN)](2) (3), [{Tp*W(µ(3)-S)(3)Cu(3)}(2)Br(µ-Br)(2)(µ(4)-Br)(MeCN)] (4), and [{Tp*W(µ(3)-S)(3)Cu(3)}(2){Cu(2)(µ-I)(4)(µ(3)-I)(2)}] (5), respectively. On the other hand, treatment of 2 with CuX (X = Cl, Br) in the presence of Et(4)NX (X = Cl, Br) produced two anionic W/Cu/S clusters [Et(4)N][{Tp*W(µ(3)-S)(3)Cu(3)X}(2)(µ-X)(2)(µ(4)-X)] (6: X = Cl; 7 X = Br). Compounds 2-7 were characterized by elemental analysis, IR, UV-vis, (1)H NMR, electrospray ionization (ESI) mass spectra, and single-crystal X-ray crystallography. The dimeric structure of 2 can be viewed as two [Tp*WS(2)] fragments in which two W atoms are connected by one S(2)(2-) dianion. Compounds 3-7 all possess unique halide-bridged double cubanelike frameworks. For 3, two [Tp*W(µ(3)-S)(3)Cu(3)](2+) dications are linked via a µ(7)-Cl(-) bridge, two µ-Cl(-) bridges, and a [Cu(MeCN)(µ-Cl)(2)](+) bridge. For 4, one [Tp*W(µ(3)-S)(3)Cu(3)(MeCN)](2+) dication and one [Tp*W(µ(3)-S)(3)Cu(3)Br](+) cation are linked via a µ(4)-Br(-) and two µ-Br(-) bridges. For 5, the two [Tp*W(µ(3)-S)(3)Cu(3)](2+) dications are bridged by a linear [(µ-I)(2)Cu(µ(3)-I)(2)Cu(µ-I)(2)](4+) species. For 6 and 7, two [Tp*W(µ(3)-S)(3)Cu(3)X](+) cations are linked by a µ(4)-X(-) and two µ-X(-) bridges (X = Cl, Br). In addition, the third-order nonlinear optical (NLO) properties of 2-7 in MeCN/CH(2)Cl(2) were investigated by using femtosecond degenerate four-wave mixing (DFWM) technique.


Asunto(s)
Boratos/síntesis química , Halógenos/química , Profármacos/síntesis química , Pirazoles/síntesis química , Tungsteno/química , Cobre/química , Cristalografía por Rayos X , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Imitación Molecular , Estructura Molecular , Nitrogenasa/química , Compuestos de Plata/química , Espectrometría de Masa por Ionización de Electrospray , Sulfuros/química
7.
J Phys Chem A ; 115(50): 14495-501, 2011 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-22040158

RESUMEN

Studies on the molecular geometries, electronic properties and second-order nonlinearities of a series of mono- and binuclear chromium carbazole complexes: (N-vinylcarbazole)Cr(CO)(3) (M1), (N-vinylcarbazole)Cr(CO)(2)PPh(3) (M2), (CO)(3)Cr(N-vinylcarbazole)Cr(CO)(3) (B1), and (CO)(3)Cr(N-vinylcarbazole)Cr(CO)(2)PPh(3) (B2) were carried out, using the density functional theory (DFT) at the B3LYP//LanL2DZ/6-31G(d) level. The experimental singlet metal-to-ligand charge transfer ((1)MLCT) spectra of these complexes can also be well simulated and discussed by the time-dependent DFT (TDDFT) at the B3LYP//LanL2DZ/6-311+G(d) level associated with the polarizable continuum model (PCM). The computational results show that an unusual characteristic of chromium carbazole structures is explained in terms of interaction between frontier molecular orbitals of the metal and its ligands. The highest occupied molecular orbitals (HOMOs) of these complexes are composed of a set of distorted degenerated Cr 3d orbitals, whereas the lowest unoccupied molecular orbitals (LUMOs) are predominantly the N-vinylcarbazole ligand π* orbitals. The HOMO-LUMO energy gaps decrease in the order NVC > M1 > B1 > M2 > B2. The considerable coupling between the carbazole and (CO)(3) in M1 creates an asymmetric environment about the chromium atom, leading to modest second-order responses. The PPh(3) ligand is acting as a donor which increases the donating strength of the d(π) orbitals in chromium carbazole species, resulting in the large electronic asymmetry in M2. As for the binuclear chromium carbazole chromophores, a wide-range (1)MLCT band and large oscillator strength are found, allowing for the electronic interactions between two metal centers which can be modified by altering the ligand bound to the metals to induce peculiar asymmetry. Essentially, Cr(CO)(3) acceptor and Cr(CO)(2)PPh(3) donor units in B2 make significant contribution to the charge-transfer process or NLO responses via conventional push-pull chromophoric architecture.

8.
Zhonghua Yi Xue Za Zhi ; 91(21): 1486-9, 2011 Jun 07.
Artículo en Zh | MEDLINE | ID: mdl-21914286

RESUMEN

OBJECTIVE: To explore the application of intracranial electrodes (IE) for temporal lobe epilepsy (TLE) surgery and assess the clinical utility of intracranial video electroencephalography (IVEEG). METHODS: The clinical data of 60 TLE patients undergoing implantation of IE were reviewed retrospectively. Cortical subdural strip, grids and depth electrodes were implanted by sphenotresia, bone disc craniotomy or stereotactic technology. RESULTS: The implanted electrodes were as follows: frontal-temporal lobe cortical strip (n = 34), frontal-anterior temporal-occipitotemporal lobe cortical strip (n = 7), bilateral temporal lobe cortical strip (n = 7), combined temporal lobe strip & depth (n = 7), anterior temporal-occipitotemporal junction cortical strip (n = 3) and combined strip & grid (n = 2). The following procedures were performed: anterior temporal lobectomy (ATL) (n = 50), combined ATL & frontal focal cortical resection (n = 7), combined ATL & callosotomy (n = 1) and combined neocortex epileptogenic focus resection & amygdalohippocampectomy (n = 2). CONCLUSION: IVEEG is effective and important for the localization of epileptogenic focus in patients with intractable temporal lobe epilepsy.


Asunto(s)
Electroencefalografía/métodos , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/cirugía , Adolescente , Adulto , Niño , Electrodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Adulto Joven
9.
Guang Pu Xue Yu Guang Pu Fen Xi ; 30(1): 83-6, 2010 Jan.
Artículo en Zh | MEDLINE | ID: mdl-20302087

RESUMEN

Monkey cerebral cortex, an important part in the brain to control action and thought activities, is mainly composed of grey matter and nerve cell. In the present paper, the in situ Raman spectra of the cerebral cortex of the birth, teenage and aged monkeys were achieved for the first time. The results show that the Raman spectra for the different age monkey cerebral cortex exhibit most obvious changes in the regions of 1000-1400 and 2800-3000 cm(-1). With monkey growing up, the relative intensities of the Raman bands at 1313 and 2885 cm(-1) mainly assigned to CH2 chain vibrational mode of lipid become stronger and stronger whereas the relative intensities of the Raman bands at 1338 and 2932 cm(-1) mainly assigned to CH3 chain vibrational mode of protein become weaker and weaker. In addition, the two new Raman bands at 1296 and 2850 cm(-1) are only observed in the aged monkey cerebral cortex, therefore, the two bands can be considered as a character or "marker" to differentiate the caducity degree with monkey growth In order to further explore the changes, the relative intensity ratios of the Raman band at 1313 cm(-1) to that at 1338 cm(-1) and the Raman band at 2885 cm(-1) to that at 2 932 cm(-1), I1313/I1338 and I2885/I2932, which are the lipid-to-protein ratios, are introduced to denote the degree of the lipid content. The results show that the relative intensity ratios increase significantly with monkey growth, namely, the lipid content in the cerebral cortex increases greatly with monkey growth. So, the authors can deduce that the overmuch lipid is an important cause to induce the caducity. Therefore, the results will be a powerful assistance and valuable parameter to study the order of life growth and diagnose diseases.


Asunto(s)
Corteza Cerebral/química , Haplorrinos , Lípidos/química , Proteínas/química , Espectrometría Raman , Envejecimiento , Animales
10.
Guang Pu Xue Yu Guang Pu Fen Xi ; 28(11): 2574-8, 2008 Nov.
Artículo en Zh | MEDLINE | ID: mdl-19271493

RESUMEN

Luxiancao is a new medicine for liver cancer, and is purely natural botanical It has good curative effects and few side effects. The curative mechanism of Luxiancao is unknown. In the present paper, the authors used a 514. 5 nm laser to measure the changes in the Raman spectrum of liver cancer cells (SMMC-7721) treated by Luxiancao at different concentrations. The study can help us know more about the mechanism, efficiency and side effects of Luxiancao. The results show that significant changes were observed in the cells' Raman spectra after reacting with Luxiancao. The intensities at 785 and 1 092 cm(-1), corresponding to DNA phosphate backbone vibration, were reduced; and the Raman bands for the bases A and G at 1 312 and 1585 cm(-1) also decreased, indicating that Luxiancao may be inserted in DNA bases and influence the DNA replications, resulting in the reduction in DNA content and breaking of the DNA strands. Besides, the intensity of 1 360 cm(-1), belonging to Trp, decreased gradually and disappeared in the end, indicating the Trp of cancer cells began to be exposed when adding in Luxiancao. The bands at 1 004 cm(-1) for Phe and 1 656 cm(-1) for proteins alpha-helix also decreased, suggesting that there were changes in the structure of protein and circumstance of amino acid. Moreover, the effects on cancer cells were enhanced gradually with the HCPT concentration increasing. Since a Raman spectrum is a chemical fingerprint of a sample, the different concentration dependent changes in the Raman spectra of individual cells due to reacting with Luxiancao can overcome the limitations of other detection systems used for quantitative and qualitative analysis of the drug.


Asunto(s)
Antineoplásicos/farmacología , Medicamentos Herbarios Chinos/farmacología , Neoplasias Hepáticas/metabolismo , Espectrometría Raman , Línea Celular Tumoral , ADN/química , ADN/efectos de los fármacos , Humanos
11.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(1): 5-7, 2007 Jan.
Artículo en Zh | MEDLINE | ID: mdl-17390635

RESUMEN

Nonlinear optical properties of Er+ doped heavy metal telluride glass were studied by picosecond laser pulses. The optical limiting response was measured by a transmission technique, and the reverse saturable absorption (RSA) by a Z-scan technique. When the incident power reached the threshold, the tranmitted power did not grow rapidly with the incident power as before, but remained almost constant. It means that the Er3+ -doped glass possesses an optical limiting effect. The experimental results show that the excited absorption is responsible for the measured RSA, resulting in optical limiting response. The measured data can be well simulated by a rate equation model to obtain the absorption cross sections of the excited state.

12.
Guang Pu Xue Yu Guang Pu Fen Xi ; 27(10): 2038-41, 2007 Oct.
Artículo en Zh | MEDLINE | ID: mdl-18306790

RESUMEN

Micro-Raman spectroscopy was employed to identify gastritis tissues and gastric ulcer tissues. The primary spectral differences between the two types of samples include, for gastric ulcer tissues, (1) the intensity of the peak at 781 cm(-1) ascribed to cytosine decreases, while the peaks ascribed to adenine and thymine respectively at 793 and 823 cm(-1) become stronger; (2) the bands of amide I and amide III at 1654 and 1320-1270 cm(-1) respectively, characteristic of alpha-helix structural protein, lose their intensities, and the tryptophan band at 1332 cm(-1) and phenylalanine band at 1003 cm(-1) reduced significantly, while the tryptophan marker at 1554 cm(-1) up shiftes to 1556 cm(-1) with increasing intensity; (3) a blue shift of 1073 cm(-1) line, the characteristic Raman band of lipid, and a reduction in the ratio of 1303 cm(-1) assigned to in-phase CH2 twisting motion to 1268 cm(-1) from =CH in-plane deformation were observed; (4) statistic analysis shows that the ratio of Raman intensities at bands 1449 cm(-1) originating from CH2 group to 1660 cm(-1) from amide I provides a promising standard to distinguish the two tissues.


Asunto(s)
Gastritis/patología , Espectrometría Raman/métodos , Úlcera Gástrica/patología , Amidas/análisis , Gastritis/diagnóstico , Humanos , Úlcera Gástrica/diagnóstico
13.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(6): 977-9, 2006 Jun.
Artículo en Zh | MEDLINE | ID: mdl-16961210

RESUMEN

By laser excitation at the wavelength of 980 nm, efficient upconversion emission at 550 nm was observed in Er3+ doped telluride glass. The upconversion intensity varies nonlinearly with the excitation power with a threshold of 44 mW. The photon response time, of the order of tens of milliseconds, is much longer than the emission lifetimes. Moreover, the response time decreases with the increase in excitation power. The power dependence of the intensity and response time indicates that the green emission is generated through photon avalanche upconversion. Compared with 690 or 579 nm excitation wavelength, 980 nm is more efficient.

14.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(3): 460-2, 2006 Mar.
Artículo en Zh | MEDLINE | ID: mdl-16830755

RESUMEN

Raman spectra of human serum albumin (HSA) and HSA-3-picolylamine complex were obtained. The spectra indicate the configuration and structural transformations of HSA. The results show that the secondary structure is main alpha-helix, and the binding of 3-picolylamine doesn't change the secondary structure. However, the binding changes the configuration of disulfide bonds, transforms a single tryptophan residue from exposed tryptophan residues to hydrophobic environment, and alters the microenvironment of tyrosine.


Asunto(s)
Picolinas/química , Albúmina Sérica/química , Sitios de Unión , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Unión Proteica , Estructura Secundaria de Proteína , Espectrometría Raman
15.
Guang Pu Xue Yu Guang Pu Fen Xi ; 26(8): 1392-5, 2006 Aug.
Artículo en Zh | MEDLINE | ID: mdl-17058929

RESUMEN

The authors achieved the temporal coherent control in an Er(3+)-doped telluride glass, one kind of disordered solids. The upconversion at 670 nm was modulated and the dephasing time was simulated as 300 fs. Moreover, the photon echo signal gave the dephasing time due to the phonon interaction. The agreement between the two data indicates that the interaction between the wavepacket and the phonon leads to the fast disappearance of wavepackets interference, which is helpful for the technique to be applied to the disordered solids.

16.
Zhonghua Yi Xue Za Zhi ; 85(46): 3286-8, 2005 Dec 07.
Artículo en Zh | MEDLINE | ID: mdl-16409821

RESUMEN

OBJECTIVE: To explore the clinical features of hippocampal lesions. METHODS: the clinical data of 21 patients with hippocampal lesions, 15 males and 6 females, aged 19 (8-42), with a duration of mesial temporal lobe epilepsy (MTLE), underwent resection of the anterior temporal lobe, amygdaloid nucleus, and hippocampus. The resected hippocampal tissues were examined pathologically. Before the operation 24-hour EEG and MRI scan were performed. The patients were followed up for 1-2 years. RESULTS: The clinical manifestations included complex partial seizure (11 cases), absence seizure (5 cases), tonic-clonic seizure (4 cases), and simple partial seizure (1 case). EEG showed spike waves in 18 patients. MRI scan showed full hippocampus and long T2 signal in 10 cases, enlarged temporal horn, hyperintense signal in T2, and decreased volume of hippocampus in 8 cases, long T1 and T2 signals and obvious space-occupying lesion in hippocampus in one case, and normal images in 2 cases. Pathological examination revealed sclerosis of hippocampus in 11 cases, astrocytoma in 6 cases, paraganglioma in 1 case, embryonic tumor of neuroepithelial tissue in 1 case, atypical hyperplasia in 1 case, and radiation necrosis in 1 case. Sixteen of the eighteen followed-up patients remained seizure-free. Statistical analysis demonstrated significant difference in MRI between hippocampal tumor and hippocampal sclerosis. CONCLUSION: MTLE patients with T2 signal and hippocampus larger than that of the contralateral side should be considered as with hippocampal tumor and as indication of operation.


Asunto(s)
Epilepsia del Lóbulo Temporal/patología , Hipocampo/patología , Adolescente , Adulto , Niño , Electroencefalografía , Epilepsia del Lóbulo Temporal/fisiopatología , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Estudios de Seguimiento , Hipocampo/fisiopatología , Hipocampo/cirugía , Humanos , Imagen por Resonancia Magnética , Masculino , Esclerosis
17.
Guang Pu Xue Yu Guang Pu Fen Xi ; 25(12): 2009-11, 2005 Dec.
Artículo en Zh | MEDLINE | ID: mdl-16544494

RESUMEN

A new method for preparing SERS-active substrate was reported. After being exposed, developed and fixed, the commercially available holographic plate can be used to generate attractive SERS-active silver surface. The obtained silver film was characterized by UV-Vis spectroscopy and scanning electron microscope (SEM) observation. The absorption spectrum locates at around 420 nm with a narrow half-width due to the surface plasmon resonance, which implies that there are silver particles on the prepared substrate with uniform sizes. And the silver particles distribute uniformly anywhere on the holographic plate with a diameter of about 100 nm by SEM observation. Furthermore, the measurements of the SERS spectrum of crystal violet indicate that such substrate has the features of satisfactory reproducibility, long term stability and high SERS activity. The prepared silver film keeps high SERS activity even if it was stored for several months in the air at room temperature.

18.
Dalton Trans ; 44(1): 130-7, 2015 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-25353691

RESUMEN

We herein describe a coordination polymer system built upon the reactions of a W/Cu/S cluster precursor [Et4N][Tp*WS3(CuBr)3] (1, Tp* = hydridotris(3,5-dimethylpyrazol-1-yl)borate) with three equivalents of CuCN through solvent modulation. Four coordination polymers, namely, [Tp*WS3Cu3(µ3-DMF)(CN)3Cu(Py)] (2), [Tp*WS3Cu3(µ3-DMF)(CN)3Cu] (3), [Tp*WS3Cu3(µ3-DMF)(CN)3Cu]·4aniline (4·4aniline) and [Tp*WS3Cu3(µ3-DMF)(CN)3Cu]·2(DMF)0.5 (5·2(DMF)0.5), are isolated in different solvent systems and characterized by means of elemental analysis, FT-IR, UV-Vis, ESI-MS and single-crystal X-ray diffraction. Compounds 2-5 feature µ3-DMF association with the nest-shaped [WS3Cu3] cluster cores, yielding cubane-type [WS3Cu3O] clusters which are further linked to single Cu(I) ions through CN bridges to provide 1D or 2D structures. Compounds 3-5 have identical chemical compositions in their main fragments but with distinctively different structural features, and are therefore topological isomers. Compound 2 has a ladder-type structure in which the side rails contain alternately linked cluster cores and Cu(I) ions. Compound 3 has a 2D (6,3) network with alternately arranged cluster cores and Cu(I) ions. Both 4 and 5 have 2D structures with 4·8(2) topology. In 4, a pair of cluster cores and Cu(I) ions form a 4-membered ring which is further linked to four equivalent rings through four CN ligands via a cluster core-to-Cu arrangement; while in the structure of 5, the same 4-membered rings as those in 4 are extended to equivalent rings via a cluster core-to-cluster and Cu-to-Cu arrangement. The hyperpolarizabilities (γ) of the polymeric networks exhibit an enhancement of more than 10 times compared to their parent cluster, 1.


Asunto(s)
Cobre/química , Cianuros/química , Polímeros/química , Compuestos de Azufre/química , Tungsteno/química , Boratos/química , Cristalografía por Rayos X , Modelos Moleculares , Compuestos Organometálicos/química , Solventes/química , Análisis Espectral
19.
Guang Pu Xue Yu Guang Pu Fen Xi ; 24(4): 385-7, 2004 Apr.
Artículo en Zh | MEDLINE | ID: mdl-15766136

RESUMEN

In the Pr3+ -doped Y2SiO5, the population in 1D2 of Pr3+ can be transferred to 3P0 state via non-radiative energy transfer by the laser excitation in resonance with 3H4-->1D2 , and we can experimentally study the Stark splitting of 3H4 energy level via 3P0 -->3H4 anti-Stokes emission spectra. Because the anti-Stokes emission spectra can avoid the energy transfer between different crystallographic site 1D2 energy levels, the above splitting lines attribution is more accurate than the assignment via 1D2-->3H4 Stokes spectra by the laser excitation in resonance with 3H4-->1D2. In addition, the character of the anti-Stokes fluorescence decay time was observed.

20.
Seizure ; 23(2): 155-7, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24287079

RESUMEN

PURPOSE: This study aimed to discuss the clinical features of seizure semiology and electroencephalography (EEG) in young children with lesional temporal lobe epilepsy (TLE). METHOD: Children with lesional TLE received presurgical evaluation for intractable epilepsy. They were followed up for more than one year after temporal lobectomy. We reviewed the medical history and video-EEG monitoring of children with TLE to analyze the semiology of seizures and EEG findings and compared the semiology of seizures and EEG findings of childhood TLE and adult TLE. RESULTS: A total of 84 seizures were analyzed in 11 children (aged 23-108 months). The age of seizure onset was from 1 month to 26 months (a mean of 17.6 months). All of the patients exhibited prominent motor manifestations including epileptic spasm, tonic seizure, and unilateral clonic seizure. Seven children manifested behavioral arrest similar to an automotor seizure in adult TLE but with a shorter duration and higher frequency. The automatisms were typically orofacial, whereas manual automatisms were rarely observed. The EEG recordings revealed that diffuse discharge patterns were more common in younger children, whereas focal or unilateral patterns were more typical in older children. All of the patients were seizure-free after temporal lobectomy with more than one-year follow-up. All of the children had a mental development delay or regression; however, there was improvement after surgery, especially in those with surgery performed early. CONCLUSION: In contrast to TLE in adults, young children with lesional TLE probably represent a distinct nosological and probably less homogeneous syndrome. Although they had generalized clinical and electrographic features, resective epilepsy surgery should be considered as early as possible to obtain seizure control and improvement in mental development.


Asunto(s)
Encéfalo/fisiopatología , Electroencefalografía , Epilepsia del Lóbulo Temporal/fisiopatología , Convulsiones/fisiopatología , Encéfalo/cirugía , Niño , Preescolar , Epilepsia del Lóbulo Temporal/etiología , Epilepsia del Lóbulo Temporal/cirugía , Femenino , Humanos , Lactante , Masculino , Monitorización Neurofisiológica , Cuidados Preoperatorios , Convulsiones/etiología , Convulsiones/cirugía , Grabación en Video
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