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81.
Helicobacter pylori (HP) is an accepted cause of chronic active gastritis and has a major causative role in peptic ulcers. It is a gastric carcinogen. Its role in nonulcer dyspepsia (NUD) is less clear, yet 50% of patients with NUD are infected with HP, and some recent literature demonstrates long-term improvement of symptoms following eradication. HP has been investigated in several other organ systems, but has not been investigated to any major degree in laryngeal disorders, a region that could be directly exposed to the bacterium from pharyngolaryngeal reflux. This study represents one arm of a larger study designed to investigate such a relationship. Of 101 patients with nonmalignant voice disorders presenting to our voice clinics, 54.5% tested positive for the H. pylori organism. Of the controls, 47.1% tested positive. When striated into age groups of < 45 years, 46–61 years, and > 62 years, and then age-matched with the controls, the likelihood of infection with the H. pylori organism was greater in both the experimental middle group, and in the middle group when combined with the elder group, than in the matched controls, and this difference demonstrated a trend approaching statistical significance. This finding is discussed in the light of other studies on HP and on gastroesophageal reflex (GER). 相似文献
82.
We critically review the ΛΛ dynamics by examining Λ - Λ and Λ-nucleon phenomenological potentials in the study of the bound
state properties of double-Λ hypernuclei
ΛΛ
6
He,
ΛΛ
10
Be,
ΛΛ
14
C,
ΛΛ
18
O,
ΛΛ
22
Ne,
ΛΛ
26
Mg,
ΛΛ
30
Si,
ΛΛ
34
S,
ΛΛ
38
Ar,
ΛΛ
42
Ca,
ΛΛ
46
Ti,
ΛΛ
50
Cr,
ΛΛ
54
Fe,
ΛΛ
58
Ni,
ΛΛ
62
Zn,
ΛΛ
66
Ge,
ΛΛ
70
Se,
ΛΛ
74
Kr,
ΛΛ
78
Sr,
ΛΛ
82
Zr,
ΛΛ
86
Mo,
ΛΛ
90
Ru,
ΛΛ
94
Pd,
ΛΛ
98
Cd,
ΛΛ
102
Sn in the frame work of (core+Λ+Λ) three body model. An effective ΛN potential is obtained by folding the phenomenological ΛN potential into the density distribution of the core nuclei. The former two cases (i.e.
ΛΛ
6
He and
ΛΛ
10
Be) are revisited to justify the correctness of the present potential model. Assuming the same potential model we predicted
some of the structural properties of heavier doubly Λ-hypernuclei. The hyperspherical harmonics expansion method, which is
an essentially exact method has been employed for the three body system. A convergence in binding energy up to 0.15% for K
max=20 has been achieved. In our calculation we have made no approximation in restricting the allowed l-values of the interacting pairs. 相似文献
83.
84.
We describe a simple means of assessing the condition of the superficial lamina propria during endoscopy, which we use in our practice as an adjunct to careful stroboscopic examination. An intake of breath against partially adducted vocal folds serves to draw the mucosa inferomedially into the glottis, which reveals areas of diminished mobility, the relationship of mucosal lesions to deeper tissues of the vocal folds, and subtle submucosal lesions. This is possible because of the unique geometry of the glottis that renders the vector forces of airflow different at inspiration and expiration. Because the integrity of the superficial lamina propria is essential to healthy phonation, we have found the inspiratory maneuver useful across a wide variety of mucosal pathologic conditions. 相似文献
85.
A detail study involving flow visualization, Laser Doppler Velocimeter (LDV) measurements and numerical prediction is presented. The visualization experiments revealed striking results of a pulsatile motion in the separated flow region associated with the formation and passage of large eddy structures. Measurements of mean velocities and turbulence intensity profiles across the separated flow field, provided information about the separated shear layer development and the recirculating flow pattern. The numerical predictions, obtained with a two-layer turbulence model in conjunction with the SIMPLE algorithm, failed to reproduce the coherent eddies and the pulsatile motion, but the mean velocities are reasonably reproduced. 相似文献
86.
Sonia Latorre Ibério de P. R. Moreira Dr. Belén Villacampa Dr. Lluís Julià Dr. Dolores Velasco Dr. Josep Maria Bofill Prof. Dr. Francisco López‐Calahorra Prof. Dr. 《Chemphyschem》2010,11(4):912-919
A detailed study of the “blocked” amino–imino tautomers derived from N‐acridine‐substituted 2‐aminobenzothiazole—and their effect on the nonlinear optical response—is presented. The synthesis, characterization, and nonlinear optical properties of these frozen tautomers, namely, N‐methyl‐N‐(2‐nitroacridin‐6‐yl)‐2‐aminobenzothia‐zole and 3‐methyl‐N‐(7‐nitroacridin‐3‐yl)‐2‐iminobenzothiazole, are reported. A theoretical model based on valence–bond theory is also proposed and used to analyze the effects of the nuclear configuration corresponding to each frozen tautomer structure. In the present case, the aromatic form and the allylic‐anion‐like system of the ? N? C? N? group inherent to each isomer are crucial for understanding and analyzing the different responses of each “blocked” tautomer. 相似文献
87.
Bardají M Calhorda MJ Costa PJ Jones PG Laguna A Reyes Pérez M Villacampa MD 《Inorganic chemistry》2006,45(3):1059-1068
The gold(I) thiolate complexes [Au(2-SC6H4NH2)(PPh3)] (1), [PPN][Au(2-SC6H4NH2)2] (2) (PPN = PPh3=N=PPh3), and [{Au(2-SC6H4NH2)}2(mu-dppm)] (3) (dppm = PPh2CH2PPh2) have been prepared by reaction of acetylacetonato gold(I) precursors with 2-aminobenzenethiol in the appropriate molar ratio. All products are intensely photoluminescent at 77 K. The molecular structure of the dinuclear derivative 3 displays a gold-gold intramolecular contact of 3.1346(4) A. Further reaction with the organometallic gold(III) complex [Au(C6F5)3(tht)] affords dinuclear or tetranuclear mixed gold(I)-gold(III) derivatives with a thiolate bridge, namely, [(AuPPh3){Au(C6F5)3}(mu2-2-SC6H4NH2)] (4) and [(C6F5)3Au(mu2-2-SC6H4NH2)(AudppmAu)(mu2-2-SC(6)H4NH2)Au(C6F5)3] (5). X-ray diffraction studies of the latter show a shortening of the intramolecular gold(I)-gold(I) contact [2.9353(7) or 2.9332(7) A for a second independent molecule], and short gold(I)-gold(III) distances of 3.2812(7) and 3.3822(7) A [or 3.2923(7) and 3.4052(7) A] are also displayed. Despite the gold-gold interactions, the mixed derivatives are nonemissive compounds. Therefore, the complexes were studied by DFT methods. The HOMOs and LUMOs for gold(I) derivatives 1 and 3 are mainly centered on the thiolate and phosphine (or the second thiolate for complex 2), respectively, with some gold contributions, whereas the LUMO for derivative 4 is more centered on the gold(III) fragment. TD-DFT results show a good agreement with the experimental UV-vis absorption and excitation spectra. The excitations can be assigned as a S --> Au-P charge transfer with some mixture of LLCT for derivative 1, an LLCT mixed with ILCT for derivative 2, and a S --> Au...Au-P charge transfer with LLCT and MC for derivative 3. An LMCT (thiolate --> Au(III) mixed with thiolate --> Au-P) excitation was found for derivative 4. The differing nature of the excited states [participation of the gold(III) fragment and the small contribution of sulfur] is proposed to be responsible for quenching the luminescence. 相似文献
88.
Thuy-Kieu Truong Ji Hyun Park MD Asiqur Rahman Martin Urbanski Eun Sung Kim Giusy Scalia Dongseok Suh 《Current Applied Physics》2019,19(2):162-167
The use of a highly aligned carbon nanotube (CNT) sheet as a multifunctional constituent for liquid crystal (LC) displays and electro-optic LC applications is assessed. The CNT sheet can perform a dual function: one is an alignment layer for LCs, replacing the commonly used rubbed polyimide film, and the other is a transparent conductive layer, taking the place of indium tin oxide. The hydrophobic treatment improved the adhesion quality between aligned CNT bundles and the glass substrate, which helps to preserve the inherently aligned nanogroove morphology of transparent CNT sheets. The test LC display cells, comprising 4-cyano-4′-pentylbiphenyl molecules sandwiched between CNT-sheet-on-glass substrates, demonstrate the operation characteristics comparable to that of the conventional cell under temperature variation and ac electric field of 1?kHz. The results offer a possibility of deploying multifunctional CNT-sheet alignment layers in LC-based devices, especially in the future flexible display applications. 相似文献
89.
90.
A nearlattice S is a meet semilattice together with the property that any two elements possessing a common upper bound have a supremum. Here the authors have introduced the notion of sectionally semicomplemented distributive nearlattices and given several characterizations of them. The skeleton SCon(S) of Con(S), the congruence lattice, consists of all those nearlattice congruences which are the pseudocomplements of members of Con(S). The relationship between skeletal congruences and kernel of skeletal congruences leads to numerous characterizations of sectionally semicomplemented distributive nearlattices and semiboolean algebras. For example we prove, for a distributive nearlattice S with 0, the following conditions are equivalent:
AMS Subject Classifications (1991): 06A12, 06A99, 06B10. 相似文献
(i) | S is sectionally semicomplemented |
(ii) | The map Θ Θ ̸ker Θ of SCon(S) onto KSCon(S) is one-to-one. |
(iii) | The map Θ Θ ̸ker Θ of SCon(S) onto KSCon(S) preserves finite joins. |
(iv) | The map Θ Θ ker ̸Θ is a lattice isomorphism of SCon(S) onto KSCon(S), whose inverse is the map J ̸ Θ(J)**. |