1,891 research outputs found
Left gastric vein on the dorsal side of the splenic artery: a rare anatomic variant revealed during gastric surgery
PURPOSE: The left gastric vein (LGV) is an important blood vessel requiring dissection during gastric surgery. We describe a rare anatomic variant of the LGV. METHODS: The LGV drainage pattern was analyzed relative to intraoperative vascular anatomy in 2,111 patients with gastric cancer who underwent radical resection from May 2007 to September 2012. The incidence of the anatomic variant was determined, and the diameter and length of the LGV and the distances from the end of the LGV to the splenoportal confluence and the root of the left gastric artery (LGA) were measured by abdominal CT reconstruction. RESULTS: In 6 of the 2,111 (0.28 %) gastric cancer patients who underwent radical resection, the LGV descended on the left side of the gastropancreatic fold, ran across the dorsal side of the splenic artery and drained into the splenic vein. The mean diameter and length of the LGV were 5.10 ± 0.40 and 37.40 ± 5.19 mm, respectively, and the mean distance from the end of the LGV to the splenoportal confluence was 13.05 ± 0.86 mm. The closer the LGV and LGA were to the root, the greater the distance between them, with a mean 13.85 ± 1.02 mm between the end of the LGV and the root of the LGA. CONCLUSIONS: In this rare anatomic variant, the LGV descends along the gastropancreatic fold, runs across the dorsal side of the splenic artery and drains into the splenic vein. Knowledge of this rare anatomic variant will help avoid damage to the LGV during gastric surgery
Localization of interacting electrons in quantum dot arrays driven by an ac-field
We investigate the dynamics of two interacting electrons moving in a
one-dimensional array of quantum dots under the influence of an ac-field. We
show that the system exhibits two distinct regimes of behavior, depending on
the ratio of the strength of the driving field to the inter-electron Coulomb
repulsion. When the ac-field dominates, an effect termed coherent destruction
of tunneling occurs at certain frequencies, in which transport along the array
is suppressed. In the other, weak-driving, regime we find the surprising result
that the two electrons can bind into a single composite particle -- despite the
strong Coulomb repulsion between them -- which can then be controlled by the
ac-field in an analogous way. We show how calculation of the Floquet
quasienergies of the system explains these results, and thus how ac-fields can
be used to control the localization of interacting electron systems.Comment: 7 pages, 6 eps figures V2. Minor changes, this version to be
published in Phys. Rev.
Efficacy of traditional Chinese herbs on squamous cell carcinoma of the esophagus: histopathologic analysis of 240 cases.
Three types of traditional Chinese herb medicine were used to treat 98 patients with advanced esophageal squamous cell carcinoma prior to surgical treatment. Forty-two patients with the same diagnosis were treated with these herbs plus cyclophosphamide (endoxan). One hundred similar patients received surgical treatment without herbs or endoxan treatment as controls. Histologic examinations of surgical specimens were made on all of these patients. Stromal lymphoid-cell infiltration and cancer tissue degeneration were more prominent in Menispernum dehuricum DC- or Chelidonium majus L-treated patients, and were less clear in patients treated with herbs plus endoxan and the controls. The antitumor action of herbs is thought to be brought about by the activation of an immunological rejection mechanism. Herbs plus endoxan may result in the masking of the immunological response of hosts without obviously damaging cancer tissues.</p
(E)-Ethyl N′-(3-hydroxybenzylidene)hydrazinecarboxylate dihydrate
The asymmetric unit of the title compound, C10H12N2O3·2H2O, contains two organic molecules with similar conformations and four water molecules. Each organic molecule is close to planar (r.m.s. deviations = 0.035 and 0.108 Å) and adopts a trans conformation with respect to its C=N bond. In the crystal, the components are linked into a three-dimensional network by N—H⋯O, O—H⋯O, O—H⋯N and C—H⋯O hydrogen bonds, some of which are bifurcated. An R
2
2(8) loop occurs between adjacent organic molecules
Mid-infrared octave-spanning supercontinuum and frequency comb generation in a suspended germanium-membrane ridge waveguide
Stable octave-spanning supercontinuum (SC) in the mid-infrared (MIR) region finds extensive applications in spectroscopy, metrology, biochemistry, etc. The absorption of conventional silicon- or silicon oxide-dominated nonlinear media makes SC generation in MIR region technically challenging. In this paper, we propose ultra-broadband MIR-SC generation using a suspended germanium-membrane ridge waveguide. We theoretically showed that when pump pulses centered at 4.8 um with pulse width at 180 fs and peak power at 800 W are injected into a 4-mm long proposed ridge waveguide, the SC generated ranges from 1.96 ~ 12 um (about 2.6 octaves), extending deep into the “fingerprint” region. The first-order coherence is calculated to confirm the stability of the generated SC. The performance of the SC-based frequency comb is also investigated by assuming a 100-pulses pump source at a repetition rate of 100 KHz
Polarization-dependent intermodal four-wave mixing in a birefringent multimode photonic crystal fiber
(E)-Methyl N′-[1-(4-methoxyphenyl)ethylidene]hydrazinecarboxylate
The molecule of the title compound, C11H14N2O3, adopts a trans configuration with respect to the C=N bond. The dihedral angle between the benzene ring and the hydrazinecarboxylate plane is 12.06 (9)°. Molecules are linked into a one-dimensional network by N—H⋯O hydrogen bonds and C—H⋯π interactions. The benzene rings of inversion-related molecules are stacked with their centroids separated by 3.777 (1) Å, indicating π–π interactions
(E)-Methyl N′-[(1H-indol-3-yl)methylidene]hydrazinecarboxylate 0.25-hydrate
The asymmetric unit of the title compound, C11H11N3O2·0.25H2O, contains two independent organic molecules and a water molecule, which lies on a twofold rotation axis. The side chains of the two molecules have slightly different orientations, the C=N—N—C torsion angle being −163.03 (15)° in one and −177.52 (14)° in the other, with each adopting a trans configuration with respect to the C=N bond. In the crystal, molecules are linked into chains extending along b by N—H⋯O, O—H⋯N and O—H⋯O hydrogen bonds and in addition, four intermolecular C—H⋯π interactions are present
(E)-Methyl N′-(2,4,5-trimethoxybenzylidene)hydrazinecarboxylate
The title molecule, C12H16N2O5, adopts a trans configuration with respect to the C=N bond. In the crystal, intermolecular N—H⋯O hydrogen bonds link the molecules into chains in [001], and weak intermolecular C—H⋯O interactions further link the chains into corrugated layers parallel to the bc plane
N′-(4-Hydroxy-3-methoxybenzylidene)acetohydrazide monohydrate
In the title compound, C10H12N2O3·H2O, the Schiff base molecule is approximately planar [within 0.189 (1) Å]. The interplanar angle between the benzene and acetohydrazide planes is 8.50 (10)°. In the crystal, molecules are linked into a three-dimensional network by strong and weak O—H⋯O and strong N—H⋯O hydrogen bonds. The hydroxy H atom deviates from the 4-hydroxy-3-methoxyphenyl mean plane by 0.319 (2) Å, probably due to the involvement of this H atom in the O—H⋯O hydrogen bond. The weak O—H⋯O hydrogen bond is involved in a bifurcated hydrogen bond with R
1
2(4) motif. A weak C—H⋯π interaction is also present
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