Publications by authors named "Sierra R"

Background: While studies have shown that postoperative wound complications can predispose to deep infection following orthopedic surgery, the best form of skin closure has not been elucidated. Furthermore, the unique risks and benefits of each type of wound closure have not been studied. The goal of this study is to present the diagnosis and treatment of patients with allergic contact dermatitis (ACD) from 2-octyl cyanoacrylate, a skin adhesive commonly used in wound closure.

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Background: Helicobacter valdiviensis is a recently described enterohepatic species isolated from wild bird's fecal samples. Currently, its pathogenic potential and clinical significance are unknown mainly due to the lack of whole-genome sequences to compare with other helicobacters and the absence of specific screenings to determine its prevalence in humans.

Materials And Methods: The species type strain (WBE14 ) was whole-genome-sequenced, and comparative analyses were carried out including the genomes from other Helicobacter species to determine the exact phylogenetic position of H.

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Cytochrome oxidase (CO), the terminal enzyme in the electron transfer chain, translocates protons across the inner mitochondrial membrane by harnessing the free energy generated by the reduction of oxygen to water. Several redox-coupled proton translocation mechanisms have been proposed, but they lack confirmation, in part from the absence of reliable structural information due to radiation damage artifacts caused by the intense synchrotron radiation. Here we report the room temperature, neutral pH (6.

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Background: Revision total hip arthroplasty (THA) is challenging specially in the presence of severe acetabular bone deficiency. We report the use of a highly porous revision shell augmented by structural allograft to provide structural support and coverage to the acetabular component.

Methods: We identified 56 patients (58 hips) undergoing revision THA, where a trabecular metal revision cup was supported by structural allograft.

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Using an X-ray laser, we investigated the crystal structure of ice formed by homogeneous ice nucleation in deeply supercooled water nanodrops (r ≈ 10 nm) at ∼225 K. The nanodrops were formed by condensation of vapor in a supersonic nozzle, and the ice was probed within 100 μs of freezing using femtosecond wide-angle X-ray scattering at the Linac Coherent Light Source free-electron X-ray laser. The X-ray diffraction spectra indicate that this ice has a metastable, predominantly cubic structure; the shape of the first ice diffraction peak suggests stacking-disordered ice with a cubicity value, χ, in the range of 0.

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Article Synopsis
  • Ecologists face challenges in selecting appropriate methods for estimating migration and this study tests and compares several of these methods using large-scale datasets from South America.
  • Five methods were assessed for their accuracy in estimating migration in spatially implicit and semi-explicit simulations, revealing that while most methods performed well in the former, accuracy in the latter depended on the balance of migration sources.
  • The study concludes that migration estimates are better viewed as approximations reflecting community resemblance and regional species pool dynamics, rather than direct measurements, emphasizing the complex relationship between migration and beta diversity.
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Cordyceps sensu lato is a genus of arthropod-pathogenic fungi, which have been used traditionally as medicinal in Asia. Within the genus, Ophiocordyceps sinensis is the most coveted and expensive species in China. Nevertheless, harvesting wild specimens has become a challenge given that natural populations of the fungus are decreasing and because large-scale culture of it has not yet been achieved.

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Clinical and microbiological characteristics of patients with prosthetic joint infection (PJI) have not been well described in the literature. The aim of this retrospective cohort study was to assess the outcome of patients with PJI and to review risk factors associated with failure of therapy. Between 1/1969 and 12/2012, 20 episodes of PJI in 17 patients were identified at our institution.

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The outcome of patients with prosthetic joint infection (PS PJI) has not been well studied. The aim of this retrospective cohort study was to assess the outcome of patients with PJI and to review risk factors associated with failure of therapy. Between 1/1969 and 12/2012, 102 episodes of PS PJI in 91 patients were identified.

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The human glucagon receptor, GCGR, belongs to the class B G-protein-coupled receptor family and plays a key role in glucose homeostasis and the pathophysiology of type 2 diabetes. Here we report the 3.0 Å crystal structure of full-length GCGR containing both the extracellular domain and transmembrane domain in an inactive conformation.

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Background: The use of a trabecular metal revision shell with metal augmentation to fill segmental or irregular defects during complex revision hip arthroplasty has been shown to provide good short-term results in prior published series. Longer-term results of the several cup-augment constructs used clinically are not known. The objective of this study was to report, with minimum 5-year radiographic and clinical follow-up, the outcome of these various constructs in revision total hip arthroplasty.

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Background: Pelvic discontinuity is uncommon and presents the surgeon with complex reconstructive challenges. The objective of this study is to report the results of current strategies used in the treatment of pelvic discontinuity.

Methods: We retrospectively analyzed prospectively collected data on 113 consecutive revision total hip arthroplasties performed for the treatment of unilateral pelvic discontinuity at a single institution.

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We provide a detailed description of selenobiotinyl-streptavidin (Se-B SA) co-crystal datasets recorded using the Coherent X-ray Imaging (CXI) instrument at the Linac Coherent Light Source (LCLS) for selenium single-wavelength anomalous diffraction (Se-SAD) structure determination. Se-B SA was chosen as the model system for its high affinity between biotin and streptavidin where the sulfur atom in the biotin molecule (CHNOS) is substituted with selenium. The dataset was collected at three different transmissions (100, 50, and 10%) using a serial sample chamber setup which allows for two sample chambers, a front chamber and a back chamber, to operate simultaneously.

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Background: A potential cause of persistent groin pain after total hip arthroplasty is impingement of the iliopsoas tendon. Treatment options include conservative management, tenotomy, and acetabular revision, but the literature, to our knowledge, has been limited to small case series on each technique. We present a series of patients with iliopsoas impingement after total hip arthroplasty and evaluate efficacy and risk factors for success or failure of each treatment strategy.

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Background: There is a paucity of data examining metal ion levels over time.

Methods: We retrospectively reviewed 59 patients (69 hips) with an articular surface replacement total hip arthroplasty. We reviewed prerevision cobalt and chromium concentrations over time.

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Early methods of tattoo removal ultimately resulted in unacceptable cosmetic outcomes. While the introduction of laser technology was an improvement over the existing chemical, mechanical, and surgical procedures, the use of nonselective tattoo removal with carbon dioxide and argon lasers led to scarring. Q-switched lasers with nanosecond (10-9) pulse domains were considered to have revolutionized tattoo treatment, by selectively heating the tattoo particles, while reducing the adverse sequelae to adjacent normal skin.

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The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of pre-Columbian impacts on Amazonian forests by overlaying known archaeological sites in Amazonia with the distributions and abundances of 85 woody species domesticated by pre-Columbian peoples. Domesticated species are five times more likely than nondomesticated species to be hyperdominant.

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X-ray crystallography at X-ray free-electron laser sources is a powerful method for studying macromolecules at biologically relevant temperatures. Moreover, when combined with complementary techniques like X-ray emission spectroscopy, both global structures and chemical properties of metalloenzymes can be obtained concurrently, providing insights into the interplay between the protein structure and dynamics and the chemistry at an active site. The implementation of such a multimodal approach can be compromised by conflicting requirements to optimize each individual method.

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Background: Prior studies comparing unicompartmental knee arthroplasty (UKA) with total knee arthroplasty (TKA) in the elderly are limited by heterogeneity in arthritic disease patterns and patient selection. We report the results of UKA and TKA in patients 75 years and older with isolated medial compartmental arthritis, with special emphasis on immediate postoperative recovery, complications, reoperation rates, and implant survivorship at midterm follow-up.

Methods: A retrospective review was performed of all patients 75 years and older who underwent UKA or TKA at our institution between 2002 and 2012.

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Systems consolidation is a time-dependent reorganization process involving neocortical and hippocampal networks underlying memory storage and retrieval. The involvement of the hippocampus during acquisition is well described; however we know much less about the concomitant contribution of cortical activity levels to the formation of stable remote memories. Here, after a reversible pharmacological inhibition of the anterior cingulate cortex (ACC) during the acquisition of a contextual fear conditioning, retrieval of both recent and remote memories were impaired, an effect that was reverted by a single memory reactivation session 48 h after training, through a destabilization-dependent mechanism interpreted as reconsolidation, that restored the normal course of systems consolidation in order to rescue a remote memory.

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Background: We postulated that a hyperthermic treatment using a 1,060 nm laser can cause a controlled adipocyte injury resulting in non-invasive fat reduction. This three-part study identified treatment parameters for a safe and tolerable treatment, demonstrated short- and long-term tissue response, and assessed the potential of this treatment for non-invasive fat reduction.

Methods: In vivo temperature measurements were conducted prior to abdominoplasty via a thermal camera (for surface readings) and thermocouple needle (for subcutaneous readings).

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Systems consolidation has been described as a time-dependent reorganization process involving the neocortical and hippocampal networks underlying memory storage and retrieval. Previous studies of our lab were able to demonstrate that systems consolidation is a dynamic process, rather than a merely passive, time-dependent phenomenon. Here, we studied the influence of sequential learning in contextual fear conditioning (CFC) with different training intensities in the time-course of hippocampal dependency and contextual specificity.

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Background: Periacetabular osteotomy (PAO) is an established treatment for symptomatic acetabular dysplasia, which is a well-recognized cause of hip pain, functional limitations, and secondary osteoarthritis. The purpose of this study was to describe the demographics of patients undergoing PAO, the baseline patient-reported outcome measures for this population, and the types of adjunctive procedures performed at the time of PAO surgery.

Methods: Demographics, disease characteristics, and patient-reported functional measures were prospectively collected from all patients who underwent PAO performed by 12 surgeons from 2008 to 2013.

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Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified.

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