1,891 research outputs found

    Left gastric vein on the dorsal side of the splenic artery: a rare anatomic variant revealed during gastric surgery

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    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

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    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.

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    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

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    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

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    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

    (E)-Methyl N′-[1-(4-methoxy­phen­yl)ethyl­idene]hydrazinecarboxyl­ate

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    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

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    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

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    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

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    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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