Publications by authors named "David Weeks"

Background: Juxta-papillary duodenal diverticulum (JPDD) has been associated with obstructive jaundice and ascending cholangitis. Potential mechanisms include periampullary colonization of pathogenic bacteria and mechanical obstruction. However, the relation of JPDD with pyogenic liver abscess (PLA) has not been reported.

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A method for calculating the analytic nonadiabatic derivative coupling terms (DCTs) for spin-orbit multi-reference configuration interaction wavefunctions is reviewed. The results of a sample calculation using a Stuttgart basis for KHe are presented. Additionally, the DCTs are compared with a simple calculation based on the Nikitin's 3 × 3 description of the coupling between the Σ and Π surfaces, as well as a method based on Werner's analysis of configuration interaction coefficients.

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Analytic gradients of electronic eigenvalues require one calculation per nuclear geometry, compared to at least 3n + 1 calculations for finite difference methods, where n is the number of nuclei. Analytic nonadiabatic derivative coupling terms (DCTs), which are calculated in a similar fashion, are used to remove nondiagonal contributions to the kinetic energy operator, leading to more accurate nuclear dynamics calculations than those that employ the Born-Oppenheimer approximation, i.e.

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The potential energy curves (PECs) of the ground and excited states that correlate in the atomic limit with Ar([Ne]3 3 ,S), Ar([Ne]3 3 4 , P, P), and Ar([Ne]3 3 4 , D, P, S, D, P, S) are calculated at the multireference configuration interaction (MRCI+Q) theoretical level with extrapolations to the complete basis set limit using all-electron correlation consistent triple-, quadruple-, and quintuple-zeta basis sets. Scalar relativistic corrections are calculated using second-order Douglas-Kroll-Hess Hamiltonian with the corresponding basis sets contracted for scalar relativistic Hamiltonians. For these calculations, the 3s orbitals of the Ar atom are not included in the active space but are correlated through single and double excitations.

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The excited state interatomic potential energy surfaces for Rb + He are computed at the spin-orbit multi-reference configuration interaction level of theory using all-electron basis sets of triple and quadruple-zeta quality that have been contracted for Douglas-Kroll-Hess (DKH) Hamiltonian and includes core-valence correlation. Davidson-Silver corrections (MRCI+Q) are employed to ameliorate size consistency error. An extrapolation of CASSCF energies is performed using the procedure of Karton and Martin whereas extrapolation of correlation energy is performed using an expression involving the inverse powers of (lmax + 1/2), the highest angular momentum value present in the basis set.

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Importance: Long-term exposure to solar radiation produces deleterious photoaging of the skin. It is not known if diet can influence skin photoaging.

Objectives: To study the influence of a calorie-restricted diet and an obesity diet in mice exposed to long-term UV-B irradiation to assess if there is an association between diet and histopathological response to UV-B irradiation.

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Scattering matrix elements of the inelastic fine structure transition M(P) + Ng ↔ M(P) + Ng are computed using the channel packet method (CPM) for alkali-metal atoms M = K, Rb, and Cs, as they collide with noble-gas atoms Ng = He, Ne, and Ar. The calculations are performed within the block Born-Oppenheimer approximation where excited state V(R), V(R), and V(R) adiabatic potential energy surfaces are used together with a Hund's case (c) basis to construct a 6 × 6 diabatic representation of the electronic Hamiltonian. Matrix elements of the angular kinetic energy of the nuclei incorporate Coriolis coupling and, together with the diabatic representation of the electronic Hamiltonian, yield a 6 × 6 effective potential energy matrix.

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Purpose: To report the lifetime activities and accomplishments of Jules Stein, MD.

Design: Retrospective review.

Methods: Assessment of published and unpublished biographical material.

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Beauty in a multicultural world.

Facial Plast Surg Clin North Am

August 2014

The increased demand for facial cosmetic surgery has come from a more diverse, informed, and selective patient population from all walks of life. Virtually no two patients have the same background or cosmetic objectives. However, the classic tenets of beauty including phi, symmetry, averageness, youthfulness, and sexual dimorphism can be applied to persons of all ethnicities to assist in objectifying the abstract concept.

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Article Synopsis
  • The study aimed to compare the effects of Z-plasty and spreader grafts on the nasal valve surface area using cadaver samples.
  • The results indicated that Z-plasty led to a 65% average increase in nasal valve surface area, significantly more than the 31% increase observed with spreader grafts.
  • Both techniques improved nasal airflow, but Z-plasty was more effective in increasing the surface area of the nasal valve.
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The X(2)Σ(1/2)(+), A(2)Π(1∕2), A(2)Π(3∕2), and B(2)Σ(1/2)(+) potential energy curves and associated dipole matrix elements are computed for M + Ng at the spin-orbit multi-reference configuration interaction level, where M = K, Rb, Cs and Ng = He, Ne, Ar. Dissociation energies and equilibrium positions for all minima are identified and corresponding vibrational energy levels are computed. Difference potentials are used together with the quasistatic approximation to estimate the position of satellite peaks of collisionally broadened D2 lines.

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The purpose of this study was to examine the impact of surgical pathology, anesthesiologist experience, and airway technique on surgically relevant outcomes in patients identified by preoperative laryngoscopy to have a difficult airway due to head and neck pathology. We prospectively recorded a series of 152 difficult airway cases due to head and neck pathology out of 2,145 direct laryngoscopies undertaken between November 2005 and June 2008. One of two senior anesthesiologists specializing in head and neck procedures intubated 101 (66.

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Lemierre Syndrome (LS) is relatively rare, and its clinical features are potentially confusing. Without proper therapy, LS is associated with significant morbidity and is potentially fatal. Recognition of the imaging features of LS in the chest and the neck may permit a timely diagnosis and lead to prompt institution of appropriate therapy.

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Objectives: Because oxidation affects platelet and coagulation factors, hemoglobin auto-oxidation in HBOCs results in the transformation to methemoglobin, which may have additive adverse effects on coagulation. The risk of coagulopathy after different dilutions of HBOC-200 with low and high methemoglobin concentrations was studied.

Design: A laboratory study on donor blood using thromboelastography (TEG; Haemoscope, Niles, IL).

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The objective of this study was to determine if coagulation is different between 6% hetastarch in normal saline (NS) and 6% hetastarch in lactated Ringer's solution (LR), with use of an ex vivo thromboelastography (TEG) model with healthy donated volunteer blood. We simulated hemodilution that occurs during clinical resuscitation of hemorrhagic or hypovolemic shock, using healthy human donor whole blood (WB) ex vivo. Coagulopathy related to low, medium, high, or very high dilution of WB with NS or a high-molecular-weight hetastarch-based plasma expander, 6% hetastarch in NS (HSNS) or 6% hetastarch in lactated Ringer's [Hextend (HSLR)], was analyzed by thromboelastography (TEG).

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Objectives: Because hetastarches have deleterious effects on coagulation that increase with molecular weight (MWt), risk of coagulopathy associated with a high MWt hemoglobin-based oxygen carrier (HBOC) was studied.

Design: Preliminary laboratory study of donor blood using thromboelastography (TEG).

Setting: University laboratory.

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Inelastic scattering matrix elements for the nonadiabatic collision B(2P1/2)+H2(1Sigmag+,j)<-->B(2P3/2)+H2(1Sigmag+,j') are calculated using the time dependent channel packet method (CPM). The calculation employs 1 2A', 2 2A', and 1 2A" adiabatic electronic potential energy surfaces determined by numerical computation at the multireference configuration-interaction level [M. H.

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Introduction: Complaints of poor water quality and skin rashes among workers at a US cardboard manufacturing facility were investigated to determine potential causes.

Methods: Employees were interviewed regarding work duties and health symptoms. Areas of dermatitis in affected employees were visually examined.

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Decreased myocardial attenuation on contrast-enhanced multidetector computed tomography (MDCT) images can be observed in subjects with myocardial infarctions (MIs). It was hypothesized that myocardial hypoattenuation in MDCT can accurately detect the presence of a healed MI as determined by cardiac magnetic resonance delayed hyperenhancement (CMR-DH). Coronary MDCT and CMR-DH were performed in 42 subjects.

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Helicobacter pylori is a Gram-negative neutralophile associated with peptic ulcers and gastric cancer. It has a unique ability to colonize the human stomach by acid acclimation. It uses the pH-gated urea channel, UreI, to enhance urea access to intrabacterial urease and a membrane-anchored periplasmic carbonic anhydrase to regulate periplasmic pH to approximately 6.

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Dendritic cell (DC) administration to CD8alpha knock-out (CD8alphaKO) mice results in a strong antigen-non-specific protection to a B16 murine melanoma tumor challenge. This response is mediated by lytic NK cells and cytokine-producing CD4 cells. We aimed to determine the signals that guide tumor targeting of this response.

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