Photocurable self-healing elastomers are promising candidates for producing complex soft devices that can mend damage. However, the practicality of these materials is limited by reliance on external stimuli, custom synthesis, manual realignment, and multihour healing cycles. This paper introduces a tough 3D-printable hybrid acrylate/thiol-ene elastomer (prepared with commercially available precursors) that exhibits nearly instantaneous damage repair in the absence of external stimuli.
View Article and Find Full Text PDFThe Qin and Western Han dynasties (221 BCE to 24 CE) represent an era of societal prosperity in China. However, due to a lack of high-resolution paleoclimate records it is still unclear whether the agricultural boost documented for this period was associated with more favorable climatic conditions. Here, multiparameter analysis of annually resolved tree-ring records and process-based physiological modeling provide evidence of stable and consistently humid climatic conditions during 270 to 77 BCE in northern China.
View Article and Find Full Text PDFRepairable adhesive elastomers are emerging materials employed in compelling applications such as soft robotics, biosensing, tissue regeneration, and wearable electronics. Facilitating adhesion requires strong interactions, while self-healing requires bond dynamicity. This contrast in desired bond characteristics presents a challenge in the design of healable adhesive elastomers.
View Article and Find Full Text PDFThe Arctic is warming faster than any other region on Earth. Putting this rapid warming into perspective is challenging because instrumental records are often short or incomplete in polar regions and precisely-dated temperature proxies with high temporal resolution are largely lacking. Here, we provide this long-term perspective by reconstructing past summer temperature variability at Yamal Peninsula - a hotspot of recent warming - over the past 7638 years using annually resolved tree-ring records.
View Article and Find Full Text PDFAsian summer monsoon (ASM) variability and its long-term ecological and societal impacts extending back to Neolithic times are poorly understood due to a lack of high-resolution climate proxy data. Here, we present a precisely dated and well-calibrated tree-ring stable isotope chronology from the Tibetan Plateau with 1- to 5-y resolution that reflects high- to low-frequency ASM variability from 4680 BCE to 2011 CE. Superimposed on a persistent drying trend since the mid-Holocene, a rapid decrease in moisture availability between ∼2000 and ∼1500 BCE caused a dry hydroclimatic regime from ∼1675 to ∼1185 BCE, with mean precipitation estimated at 42 ± 4% and 5 ± 2% lower than during the mid-Holocene and the instrumental period, respectively.
View Article and Find Full Text PDFFacial Plast Surg Aesthet Med
August 2021
The risk of hematoma formation after rhytidectomy is gender associated and can lead to postoperative complications. The literature to help explain and elucidate the mechanism behind this gender-associated risk is poorly developed and requires further investigation. The objective of this study was to compare facial skin micro-vessel density of female and male-to-female (MTF) transgender patients undergoing rhytidectomy to better understand the mechanism of gender-correlated hematoma risk factors.
View Article and Find Full Text PDFCRU TS (Climatic Research Unit gridded Time Series) is a widely used climate dataset on a 0.5° latitude by 0.5° longitude grid over all land domains of the world except Antarctica.
View Article and Find Full Text PDFJ Oral Biol Craniofac Res
December 2017
Purpose: To evaluate 10-year patient data related to mandibular reconstruction with NVBG at a tertiary academic center.
Patients And Methods: Sixty patients with mandibular mandibular reconstruction were included. Patients were divided to continuity defect and non-continuity defect.
Purpose Of Review: Management of headache disorders is not part of most craniomaxillofacial surgery practices; however there are certain indications for surgical management of headaches by the craniomaxillofacial surgeon.
Recent Findings: Migraine headaches are the most amenable to surgical management and while the exact mechanism of migraine is unknown, a central or peripheral trigger such as compressive neuropathy of trigeminal nerve branches leading to neurogenic inflammation has been suggested. The primary management for episodic migraine headache should be lifestyle modification and medication, whereas for chronic migraine (>15 headache days/month) use of medication and botulinum neurotoxin is effective, whereas some patients may choose to explore surgical options.
Objective: The aim of this article is to review the mechanism of action, physiological effects, and therapeutic applications of botulinum neurotoxins in the head and neck area.
Study Design: An extensive literature search was performed using keywords. The resulting articles were analyzed for relevance in four areas: overview on botulinum neurotoxins, the role of botulinum neurotoxins in the management of salivary secretory disorders, the role of botulinum neurotoxins in the management of facial pain, and the role of botulinum neurotoxins in head and neck movement disorders.
Proc Natl Acad Sci U S A
February 2014
An annually resolved and absolutely dated ring-width chronology spanning 4,500 y has been constructed using subfossil, archaeological, and living-tree juniper samples from the northeastern Tibetan Plateau. The chronology represents changing mean annual precipitation and is most reliable after 1500 B.C.
View Article and Find Full Text PDFWe combine satellite and ground observations during 1950-2011 to study the long-term links between multiple climate (air temperature and cryospheric dynamics) and vegetation (greenness and atmospheric CO(2) concentrations) indicators of the growing season of northern ecosystems (>45°N) and their connection with the carbon cycle. During the last three decades, the thermal potential growing season has lengthened by about 10.5 days (P < 0.
View Article and Find Full Text PDFBackground: Clinical experience with surgical decompression of specific peripheral nerves in the head and neck for the relief of migraine headache symptoms has proven to be effective in most patients. Some patients, however, continue to have residual symptoms after these procedures. In an effort to better understand potential etiologies for failure of treatment, an investigation was performed to determine whether or not vascular-mediated peripheral trigger points exist that have heretofore been undescribed that may be contributing to persistent symptomatology.
View Article and Find Full Text PDFBackground: Adenosine regulates pain transmission by actions at spinal, supraspinal, and peripheral sites. A few studies have suggested that administration of adenosine might be associated with anesthetic- and analgesic-sparing effects. The primary aim of this multicenter study was to determine the dose-response profile of adenosine with respect to perioperative analgesia.
View Article and Find Full Text PDFOral Maxillofac Surg Clin North Am
August 2008
Reconstruction of congenital, developmental, or acquired head and neck defects remains a significant challenge for the oral and maxillofacial surgeon. Microvascular free tissue transfer has several advantages over nonvascularized bone grafts and pedicled soft tissue flaps that currently make it the modality of choice for the reconstruction of extirpative defects of the head and neck. Preoperative planning must include detailed attention to the technical aspects of the microvascular procedure.
View Article and Find Full Text PDFOral Maxillofac Surg Clin North Am
August 2008
Knowledge of the management of infections of the deep spaces of the neck is essential to the daily practice of oral and maxillofacial surgery. Timely decisions must be made through the acute course of the disease. Interventions must be performed with the appropriate surgical skill.
View Article and Find Full Text PDFBackground: Improvements in imaging technology, particularly computed tomographic angiography (CTA), have altered the management of patients with penetrating injuries in the neck. The purpose of this retrospective study is to evaluate our 5-year experience with the management of penetrating injuries to the neck, to the further elucidate the role of CTA in clinical decision making, and to assess treatment outcome.
Methods: Clinical variables were collected and evaluated on all patients with penetrating injuries to the neck presenting to the Legacy Emanuel Hospital Trauma Service from 2000 to 2005.
J Oral Maxillofac Surg
April 2007
Purpose: Improvements in imaging technology, particularly computed tomographic angiography (CTA), have altered the management of patients with penetrating neck injuries. Although some centers still advocate routine exploration for all zone 2 neck injuries penetrating the platysma, many civilian centers in the United States have adopted a policy of selective exploration based on clinical and radiographic examination. The purpose of this retrospective study is to evaluate our 5-year experience with the management of penetrating neck injuries, to further elucidate the role of CTA in clinical decision-making, and to assess treatment outcome.
View Article and Find Full Text PDFPeriods of widespread warmth or cold are identified by positive or negative deviations that are synchronous across a number of temperature-sensitive proxy records drawn from the Northern Hemisphere. The most significant and longest duration feature during the last 1200 years is the geographical extent of warmth in the middle to late 20th century. Positive anomalies during 890 to 1170 and negative anomalies during 1580 to 1850 are consistent with the concepts of a Medieval Warm Period and a Little Ice Age, but comparison with instrumental temperatures shows the spatial extent of recent warmth to be of greater significance than that during the medieval period.
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