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1.
Nature ; 615(7950): 50-55, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36859583

RESUMO

The newly discovered nickelate superconductors so far only exist in epitaxial thin films synthesized by a topotactic reaction with metal hydrides1. This method changes the nickelates from the perovskite to an infinite-layer structure by deintercalation of apical oxygens1-3. Such a chemical reaction may introduce hydrogen (H), influencing the physical properties of the end materials4-9. Unfortunately, H is insensitive to most characterization techniques and is difficult to detect because of its light weight. Here, in optimally Sr doped Nd0.8Sr0.2NiO2H epitaxial films, secondary-ion mass spectroscopy shows abundant H existing in the form of Nd0.8Sr0.2NiO2Hx (x ≅ 0.2-0.5). Zero resistivity is found within a very narrow H-doping window of 0.22 ≤ x ≤ 0.28, showing unequivocally the critical role of H in superconductivity. Resonant inelastic X-ray scattering demonstrates the existence of itinerant interstitial s (IIS) orbitals originating from apical oxygen deintercalation. Density functional theory calculations show that electronegative H- occupies the apical oxygen sites annihilating IIS orbitals, reducing the IIS-Ni 3d orbital hybridization. This leads the electronic structure of H-doped Nd0.8Sr0.2NiO2Hx to be more two-dimensional-like, which might be relevant for the observed superconductivity. We highlight that H is an important ingredient for superconductivity in epitaxial infinite-layer nickelates.

2.
Nature ; 605(7909): 262-267, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35546188

RESUMO

The scaling of silicon metal-oxide-semiconductor field-effect transistors has followed Moore's law for decades, but the physical thinning of silicon at sub-ten-nanometre technology nodes introduces issues such as leakage currents1. Two-dimensional (2D) layered semiconductors, with an atomic thickness that allows superior gate-field penetration, are of interest as channel materials for future transistors2,3. However, the integration of high-dielectric-constant (κ) materials with 2D materials, while scaling their capacitance equivalent thickness (CET), has proved challenging. Here we explore transferrable ultrahigh-κ single-crystalline perovskite strontium-titanium-oxide membranes as a gate dielectric for 2D field-effect transistors. Our perovskite membranes exhibit a desirable sub-one-nanometre CET with a low leakage current (less than 10-2 amperes per square centimetre at 2.5 megavolts per centimetre). We find that the van der Waals gap between strontium-titanium-oxide dielectrics and 2D semiconductors mitigates the unfavourable fringing-induced barrier-lowering effect resulting from the use of ultrahigh-κ dielectrics4. Typical short-channel transistors made of scalable molybdenum-disulfide films by chemical vapour deposition and strontium-titanium-oxide dielectrics exhibit steep subthreshold swings down to about 70 millivolts per decade and on/off current ratios up to 107, which matches the low-power specifications suggested by the latest International Roadmap for Devices and Systems5.

3.
Nanotechnology ; 35(24)2024 Mar 27.
Artigo em Inglês | MEDLINE | ID: mdl-38387088

RESUMO

The recombination of photoexcited electron-hole pairs greatly limits the degradation performance of photocatalysts. Ultrasonic cavitation and internal electric field induced by the piezoelectric effect are helpful for the separation of electron-hole pairs and degradation efficiency. The activated foam carbon (AFC) owing to its high surface area is often used as the substrate to grow catalysts to provide more reactive active sites. In this work, CuO@BaTiO3(CuO@BTO) heterostructure is prepared by hydrothermal method on the surface of AFC to investigate the ultrasonic piezoelectric catalysis effect. X-ray diffraction (XRD), Raman spectroscopy, energy dispersive x-ray spectroscopy (EDS) and scanning electron microscopy (SEM) were used to analyze the structure and morphology of CuO-BTO/AFC composite. It is found that the CuO-BTO/AFC composite exhibits excellent piezo-catalytic performance for the degradation of organics promoted by ultrasonic vibration. The CuO-BTO/AFC composite can decompose methyl orange and methylene blue with degradation efficiency as high as 93.9% and 97.6% within 25 min, respectively. The mechanism of piezoelectricity enhanced ultrasound supported catalysis effect of system CuO-BTO/AFC is discussed. The formed heterojunction structure between BTO and CuO promotes the separation of positive and negative charges caused by the piezoelectric effect.

4.
Neuromodulation ; 2024 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-38878054

RESUMO

INTRODUCTION: The International Neuromodulation Society convened a multispecialty group of physicians based on expertise and international representation to establish evidence-based guidance on the mitigation of neuromodulation complications. This Neurostimulation Appropriateness Consensus Committee (NACC)® project intends to update evidence-based guidance and offer expert opinion that will improve efficacy and safety. MATERIALS AND METHODS: Authors were chosen on the basis of their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to October 2023. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant. RESULTS: The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process. CONCLUSIONS: The NACC recommends best practices regarding the mitigation of complications associated with neurostimulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be used as a guide to assist decision-making when clinically appropriate.

5.
Small ; 19(10): e2206648, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36538737

RESUMO

Bi2 O2 Se is the most promising 2D material due to its semiconducting feature and high mobility, making it propitious channel material for high-performance electronics that demands highly crystalline Bi2 O2 Se at low-growth temperature. Here, a low-temperature salt-assisted chemical vapor deposition approach for growing single-domain Bi2 O2 Se on a millimeter scale with thicknesses of multilayer to monolayer is presented. Because of the advantage of thickness-dependent growth, systematical scrutiny of layer-dependent Raman spectroscopy of Bi2 O2 Se from monolayer to bulk is investigated, revealing a redshift of the A1g mode at 162.4 cm-1 . Moreover, the long-term environmental stability of ≈2.4 nm thick Bi2 O2 Se is confirmed after exposing the sample for 1.5 years to air. The backgated field effect transistor (FET) based on a few-layered Bi2 O2 Se flake represents decent carrier mobility (≈287 cm2  V-1 s-1 ) and an ON/OFF ratio of up to 107 . This report indicates a technique to grow large-domain thickness controlled Bi2 O2 Se single crystals for electronics.

6.
Bioinformatics ; 38(17): 4220-4222, 2022 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-35801945

RESUMO

SUMMARY: Missense mutations that change protein stability are strongly associated with human genetic disease. With the recent availability of predicted structures for all human proteins generated using the AlphaFold2 prediction model, genome-wide assessment of the stability effects of genetic variation can, for the first time, be easily performed. This facilitates the interrogation of personal genetic variation for potentially pathogenic effects through the application of stability metrics. Here, we present a novel tool to prioritize variants predicted to cause strong instability in essential proteins. We show that by filtering by ΔΔG values and then prioritizing by StabilitySort Z-scores, we are able to more accurately discriminate pathogenic, protein-destabilizing mutations from population variation, compared with other mutation effect predictors. AVAILABILITY AND IMPLEMENTATION: StabilitySort is available as a web service (https://www.stabilitysort.org), as a data download for integration with other tools (https://www.stabilitysort.org/download) or can be deployed as a standalone system from source code (https://gitlab.com/baaron/StabilitySort). SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Assuntos
Genoma , Software , Humanos , Proteínas/genética , Estabilidade Proteica , Mutação , Variação Genética
7.
Neuromodulation ; 26(5): 1039-1046, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35643846

RESUMO

OBJECTIVES: Pain score, functional disability, and health-related quality of life (HRQoL) are core outcome domains for chronic pain clinical trials. Although greater levels of pain reduction have been shown to be linked to larger gains in HRQoL, little is known of the association between HRQoL and disability in the setting of chronic pain. The aims of this study were to 1) investigate the association between functional disability and HRQoL and 2) estimate the utility values associated with levels of functional disability in patients treated with evoked compound action potential (ECAP) spinal cord stimulation (SCS) for chronic pain. MATERIALS AND METHODS: Data on functional disability assessed using the Oswestry Disability Index (ODI) and HRQoL (EQ-5D-5L) were collected from 204 patients with an Evoke ECAP-SCS device and followed up to 12 months. SF-6D utility scores also were retrieved for 134 of these patients. Multivariable linear regression models adjusted for baseline utility values and patient demographics were used to compare differences in utility values across ODI categories. RESULTS: Significant improvements in functional disability and HRQoL were observed at three- and 12-month follow-up after SCS. Patients reporting "minimum disability," "moderate disability," "severe disability," and "crippled" had mean EQ-5D scores of 0.82, 0.73, 0.59, and 0.45, respectively. The mean change in EQ-5D score was 0.007 per unit change in total ODI score. The R2 statistic showed a moderate level association (49%-64% of variance in EQ-5D explained by ODI). CONCLUSION: ECAP-SCS results in significant improvements in functional disability and HRQoL. This study shows that improvement in function of people with chronic pain before and after ECAP-SCS is associated with improvement in HRQoL.


Assuntos
Dor Crônica , Estimulação da Medula Espinal , Humanos , Dor Crônica/terapia , Estimulação da Medula Espinal/métodos , Qualidade de Vida , Potenciais de Ação , Medição da Dor/métodos , Inquéritos e Questionários
8.
Neuromodulation ; 26(7): 1295-1308, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37632517

RESUMO

OBJECTIVE: Emerging spinal cord stimulation (SCS) remote monitoring and programming technologies provide a unique opportunity to address challenges of in-person visits and improve patient care, although clinical guidance on implementation is needed. The goal of this document is to establish best clinical practices for integration of remote device management into the care of patients with SCS, including remote monitoring and remote programming. MATERIALS AND METHODS: A panel of experts in SCS met in July 2022, and additional experts contributed to the development of recommendations after the meeting via survey responses and correspondence. RESULTS: Major goals of remote SCS device management were identified, including prompt identification and resolution of SCS-related issues. The panel identified metrics for remote monitoring and classified them into three categories: device-related (eg, stimulation usage); measurable physiologic or disease-related (eg, patient physical activity or pedometry); and patient-reported (eg, sleep quality and pain intensity). Recommendations were made for frequency of reviewing remote monitoring metrics, although providers should tailor follow-up to individual patient needs. Such periodic reviews of remote monitoring metrics would occur separately from automatic monitoring system notifications (if key metrics fall outside an acceptable range). The guidelines were developed in consideration of reimbursement processes, privacy concerns, and the responsibilities of the care team, industry professionals, manufacturers, patients, and caregivers. Both existing and needed clinical evidence were covered, including outcomes of interest for future studies. CONCLUSIONS: Given the expansion of SCS device capabilities, this document provides critical guidance on best practices for using remote device management, although medical necessity should drive all remote monitoring decisions, with individualized patient care. The authors also describe the potential of these emerging technologies to improve outcomes for patients with SCS, although more clinical evidence is needed.


Assuntos
Dor Crônica , Estimulação da Medula Espinal , Humanos , Dor Crônica/terapia , Manejo da Dor , Medula Espinal
9.
Neuromodulation ; 26(5): 1030-1038, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36437161

RESUMO

OBJECTIVE: Spinal cord stimulation (SCS) is considered an effective interventional nonpharmacologic treatment option for several chronic pain conditions. Here we present the effects of the novel evoked compound action potential (ECAP) controlled closed-loop (ECAP-CL) SCS system on long-term sleep quality outcomes from the EVOKE study. MATERIALS AND METHODS: The EVOKE study is a double-blind, randomized, controlled clinical trial conducted at 13 sites in the United States (N = 134 patients). The clinical trial utilized SCS to manage chronic pain and compared novel ECAP-CL technology to open-loop SCS. Additionally, sleep quality data was collected using the Pittsburgh Sleep Quality Index (PSQI) at baseline and all study visits. RESULTS: The mean PSQI global score for ECAP-CL patients at baseline was 14.0 (n = 62; ± 0.5, SD 3.8), indicating poor sleep quality. Clinically meaningful and statistically significant reductions (p < 0.001) in the global PSQI scores were noted at 12 months (n = 55; 5.7 ± 0.6, SD 4.2). A total of 76.4% of ECAP-CL patients met or exceeded Minimal Clinically Important Difference from baseline in PSQI at 12 months. Additionally, 30.9% of ECAP-CL patients achieved "good sleep quality" scores (PSQI ≤ 5), and 29.1% achieved sleep quality remission. "Normative" sleep scores were observed in 29.6% of ECAP-CL patients at 12 months, and these scores were better than the US general population. Additionally, ECAP-CL patients achieved statistically significant changes from baseline (p < 0.01) across all seven subcomponent scores of PSQI at 12 months. CONCLUSIONS: ECAP-CL SCS elicits consistent neural activation of the target leading to less variability in long-term therapy delivery. In the EVOKE study, this resulted in ECAP-CL patients demonstrating clinically superior and sustained pain relief. Results from this study provide new evidence of long-term improvement in sleep quality and quantity in patients with chronic pain resulting from the use of this novel ECAP-CL SCS technology. CLINICAL TRAIL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT02924129.


Assuntos
Dor Crônica , Estimulação da Medula Espinal , Humanos , Dor Crônica/terapia , Dor Crônica/etiologia , Potenciais de Ação/fisiologia , Qualidade do Sono , Estimulação da Medula Espinal/métodos , Potenciais Evocados/fisiologia , Resultado do Tratamento , Medula Espinal/fisiologia
10.
Neuromodulation ; 26(7): 1400-1411, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37589641

RESUMO

OBJECTIVE: This study aimed to assess the safety and effectiveness of a new charge-distributed multiphase stimulation paradigm during an extended spinal cord stimulation (SCS) trial. MATERIALS AND METHODS: This prospective, multicenter, randomized, single-blind, feasibility study included participants with chronic low back and/or leg pain and baseline numerical rating scale (NRS) for overall pain intensity ≥6. After a successful commercial SCS trial, participants were randomized to multiphase SCS therapy A (approximately 600-1500 Hz) or B (approximately 300-600 Hz), delivered via an investigational external pulse generator and existing leads during an 11-to-12-day testing period. Primary end points were mean NRS change from baseline to final in-office visit for each multiphase therapy and between therapies. Secondary end points included mean NRS change from end of commercial trial to final study visit and incidence of device-related adverse events (AEs). Additional measures included patient-reported outcomes collected at home through electronic watches and written diaries. Power usage was compared between multiphase and commercial therapies. RESULTS: A total of 122 participants initiated a commercial trial; 77 were randomized to a multiphase arm, and 65 completed the study. Reductions in mean NRS scores from baseline to final study visit were significant for multiphase therapy A and B (-4.3 and -4.7, respectively; both p < 0.0001). There was no statistically significant difference in mean NRS reduction or percent pain relief between multiphase therapies. In an additional analysis, 63.9% of participants reported greater pain relief with multiphase than with commercial SCS therapy in the at-home setting. On average, multiphase required less power than did commercial devices. One non-serious device-related AE was reported, and no infections occurred during the extended trial. CONCLUSIONS: Multiphase SCS effectively reduced pain in participants with chronic low back and/or leg pain during a trial, with no unanticipated device-related AEs reported. Future studies should evaluate long-term effectiveness of multiphase stimulation. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT03594266.


Assuntos
Dor Crônica , Estimulação da Medula Espinal , Humanos , Estimulação da Medula Espinal/efeitos adversos , Estimulação da Medula Espinal/métodos , Dor Crônica/diagnóstico , Dor Crônica/terapia , Perna (Membro) , Estudos Prospectivos , Método Simples-Cego , Resultado do Tratamento , Medula Espinal
11.
Opt Express ; 30(20): 35807-35816, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36258523

RESUMO

Neutron irradiation induced degradation of porous silica film is studied by Molecular Dynamics and Density-Functional theory-based methods. The degradation of microscopic structure, thermal property, and optical property of porous silica film are systematically investigated. Low-energy recoil is used to simulate the neutron irradiation effect. The pair and bond angle distributions, and coordination number distributions reveal that, under neutron irradiation, the microscopic structure of porous silica film is obviously modified, and the coordination defects are induced. We find that the higher recoil energy, the more coordination defects are formed in the film. The increased defects lead to a decrease in thermal conductivity. In addition, neutron irradiation induces additional optical absorption peaks in UV region and increasement in refractive index, resulting in a noticeable reduction in light transmittance. The detailed calculation of density of states reveals that these optical absorption peaks originate from the irradiation induced defect states in band gap. Our work shows that low-energy neutron irradiation can induce obvious defect density and degrade thermal and optical properties of porous silica film, which are responsible for subsequent laser-induced damage.

12.
Opt Express ; 29(20): 31849-31858, 2021 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-34615268

RESUMO

As a high-performance optical material, fused silica is widely applied in high-power laser and photoelectric systems. However, laser induced damage (LID) of fused silica severely limits the output power and performance of these systems. Due to the values in strong field physics and improving the load capacity and performance of high power systems at UV laser, LID at 355 nm of fused silica has attracted much attention. It has been found that, even be treated by advanced processing technologies, the actual damage threshold of fused silica at 355 nm is far below the intrinsic threshold. It means that there is an absorption source near 355 nm in fused silica. However, to date, the absorption source is still unknown. In this paper, a absorption source near 355 nm is found by first-principles calculations. We find that the absorption source near 355 nm is neutral oxygen-vacancy defect (NOV, ≡Si-Si≡) and this defect originates from the oxygen deficiency of fused silica. Our results indicate that NOV defect can be taken as a damage precursor for 355 nm UV laser, and this precursor can be obviously reduced by increasing the ratio of oxygen to silicon. Present work is valuable for exploring damage mechanisms and methods to improve the damage threshold of fused silica at UV laser.

13.
Phys Rev Lett ; 126(17): 176401, 2021 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-33988439

RESUMO

Improving the efficiency of charge separation (CS) and charge transport (CT) is essential for almost all optoelectronic applications, yet its maximization remains a big challenge. Here we propose a conceptual strategy to achieve CS efficiency close to unity and simultaneously avoid charge recombination (CR) during CT in a ferroelectric polar-discontinuity (PD) superlattice structure, as demonstrated in (BaTiO_{3})_{m}/(BiFeO_{3})_{n}, which is fundamentally different from the existing mechanisms. The competition of interfacial dipole and ferroelectric PD induces opposite band bending in BiFeO_{3} and BaTiO_{3} sublattices. Consequently, the photoexcited electrons (e) and holes (h) in individual sublattices move forward to the opposite interfaces forming electrically isolated e and h channels, leading to a CS efficiency close to unity. Importantly, the spatial isolation of conduction channels in (BaTiO_{3})_{m}/(BiFeO_{3})_{n} enable suppression of CR during CT, thus realizing a unique band diagram for spatially orthogonal CS and CT. Remarkably, (BaTiO_{3})_{m}/(BiFeO_{3})_{n} can maintain a high photocurrent and large band gap simultaneously. Our results provide a fascinating illumination for designing artificial heterostructures toward ideal CS and CT in optoelectronic applications.

14.
Pain Med ; 22(3): 548-560, 2021 03 18.
Artigo em Inglês | MEDLINE | ID: mdl-33616178

RESUMO

OBJECTIVE: Lumbar radiofrequency ablation is a commonly used intervention for chronic back pain. However, the pain typically returns, and though retreatment may be successful, the procedure involves destruction of the medial branch nerves, which denervates the multifidus. Repeated procedures typically have diminishing returns, which can lead to opioid use, surgery, or implantation of permanent neuromodulation systems. The objective of this report is to demonstrate the potential use of percutaneous peripheral nerve stimulation (PNS) as a minimally invasive, nondestructive, motor-sparing alternative to repeat radiofrequency ablation and more invasive surgical procedures. DESIGN: Prospective, multicenter trial. METHODS: Individuals with a return of chronic axial pain after radiofrequency ablation underwent implantation of percutaneous PNS leads targeting the medial branch nerves. Stimulation was delivered for up to 60 days, after which the leads were removed. Participants were followed up to 5 months after the start of PNS. Outcomes included pain intensity, disability, and pain interference. RESULTS: Highly clinically significant (≥50%) reductions in average pain intensity were reported by a majority of participants (67%, n = 10/15) after 2 months with PNS, and a majority experienced clinically significant improvements in functional outcomes, as measured by disability (87%, n = 13/15) and pain interference (80%, n = 12/15). Five months after PNS, 93% (n = 14/15) reported clinically meaningful improvement in one or more outcome measures, and a majority experienced clinically meaningful improvements in all three outcomes (i.e., pain intensity, disability, and pain interference). CONCLUSIONS: Percutaneous PNS has the potential to shift the pain management paradigm by providing an effective, nondestructive, motor-sparing neuromodulation treatment.


Assuntos
Ablação por Radiofrequência , Estimulação Elétrica Nervosa Transcutânea , Dor nas Costas , Humanos , Nervos Periféricos , Estudos Prospectivos , Resultado do Tratamento
15.
Ann Plast Surg ; 86(5S Suppl 3): S379-S383, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33976066

RESUMO

BACKGROUND: Total parotidectomy with facial nerve sacrifice creates 2 challenging reconstructive problems: restoration of facial contour and facial nerve rehabilitation. Strong evidence suggesting that vascularized nerve grafts are superior to nonvascularized nerve grafts motivated our team to develop a chimeric scapulodorsal flap combining the usual harvestable local tissues with the vascularized latissimus dorsi motor nerve (SD-LDVxN). We present our experiences developing a new program at University of California, San Diego, highlighting our first case here, and present preliminary retrospective results focusing on the functional outcomes of facial nerve reanimation. MATERIALS AND METHODS: The first case performed in the United States was a 57-year-old woman with stage IVA left parotid adenoid cystic carcinoma and House-Brackmann grade 6 facial palsy. She underwent total parotidectomy with facial nerve sacrifice and a free chimeric SD-LDVxN flap reconstruction. She had an unremarkable postoperative course, and 3- and 6-month follow-up functional results are reported. Preliminary functional results from our total series of 25 patients were reported. RESULTS: At her 3-month follow-up, she was a House-Brackmann 5 with a static eFACE score of 37, dynamic eFACE score of 31, and smile eFACE score of 48. At her 6-month follow-up, she was a House-Brackmann 5 with a static eFACE score of 50, dynamic eFACE score of 27, and smile eFACE score of 53. Preliminary results from our total series of 25 patients with an average of 5 years of follow-up were a House-Brackmann 2.5 and eFACE scores of 83.1 for static facial symmetry, 67.5 for dynamic facial symmetry, and 77.7 for smile score. Twenty of the 25 patients had postoperative radiotherapy. No local tumor recurrence had been reported. The average reinnervation time was 9 months and ranged from 3 to 15 months. CONCLUSIONS: The SD-LDVxN flap is a highly resourceful solution to reconstruct complex parotid defects, especially those that sacrifice the facial nerve. The vascularized nerve graft allows for primary facial reanimation. Nerve recovery may be superior to what could be expected with a conventional nerve graft.


Assuntos
Paralisia Facial , Neoplasias Parotídeas , Procedimentos de Cirurgia Plástica , Músculos Superficiais do Dorso , Nervo Facial/cirurgia , Paralisia Facial/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Parotídeas/cirurgia , Estudos Retrospectivos , Retalhos Cirúrgicos
16.
Nano Lett ; 20(2): 1262-1271, 2020 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-31877053

RESUMO

Conventional refrigeration methods based on compression-expansion cycles of greenhouse gases are environmentally threatening and cannot be miniaturized. Electrocaloric effects driven by electric fields are especially well suited for implementation of built-in cooling in portable electronic devices. However, most known electrocaloric materials present poor cooling performances near room temperature, contain toxic substances, and require high electric fields. Here, we show that lead-free ferroelectric thin-film bilayers composed of (Bi0.5Na0.5)TiO3-BaTiO3 (BNBT) and Ba(Zr0.2Ti0.8)O3-(Ba0.7Ca0.3)TiO3 (BCZT) display unprecedentedly large electrocaloric effects of ∼23 K near room temperature under moderate electric bias. The giant electrocaloric effect observed in BNBT/BCZT bilayers, which largely surpasses the sum of the individual caloric responses measured in BNBT and BCZT, is originated from the presence of compositional bound charges at their interface. Our discovery of interface charge-induced giant electrocaloric effects indicates that multilayered oxide heterostructures hold tremendous promise for developing highly efficient and scalable solid-state cooling applications.

17.
J Reconstr Microsurg ; 37(3): 282-291, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33142333

RESUMO

BACKGROUND: Cancer involving the parotid gland region may originates from parotid parenchyma itself or from locoregional organs and in rare cases, the facial nerve (FN) has to be sacrificed during tumor resection. In these cases, cancer extension often goes beyond the parotid compartment and requires extensive local resection responsible for complex multitissular defects. The goals of reconstruction may be summarized in the following two components: (1) restoration of the volumetric tissue defect and (2) FN reconstruction. The aim of this study is to describe our surgical technique and our cosmetic results using the chimeric scapulodorsal vascularized nerve (SDVN) flap to reconstruct extensive maxillofacial defects associated with FN sacrifice. METHODS: All patients undergone an extensive maxillofacial resection with FN sacrifice and primarily reconstructed with a SDVN flap were included. We classified the maxillofacial defects into six groups based on the type of resection. Intraoperative data including flap composition, topography of FN injury, length of nerve gap, and number of nervous anastomosis were recorded. RESULTS: Twenty-nine patients were included. Mean follow-up was 38.7 months. The harvested flaps included the SDVN combined with different components according to the defect group. A satisfactory volumetric restoration was obtained in 93% of cases. The mean number of distal nervous anastomosis was 4.5. The length of the vascularized grafted nerve ranged from 7 to 10 cm. CONCLUSION: This is largest series presented in literature on primary FN reconstruction utilizing a vascularized nerve graft. We believe that the chimeric SDVN flap should be highly considered for these cases due to its versatility. The surgeon is able to use single donor site available soft and hard tissues components along with a vascular motor nerve graft, which offers a great length and number of distal branches, and easily matches with the extracranial FN trunk and its peripheral ramifications.


Assuntos
Retalhos de Tecido Biológico , Procedimentos de Cirurgia Plástica , Face , Nervo Facial/cirurgia , Humanos , Região Parotídea
18.
Pain Pract ; 21(1): 45-53, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615017

RESUMO

BACKGROUND: Chronic pelvic pain (CPP) is a debilitating condition that often leads to disability and does not respond to conventional treatments. This study was conducted to evaluate the effects of paresthesia-independent 10-kHz spinal cord stimulation (SCS) in subjects with CPP. METHODS: This prospective, single-arm pilot study enrolled subjects with clinical diagnoses of CPP and mean pain scores of ≥ 5.0 cm on a 10-cm VAS. Subjects underwent trial stimulations with 10-kHz SCS, and those who had successful trial stimulations (≥40% pain relief) received permanently implanted devices and were followed for 12 months. RESULTS: Of the 21 subjects who underwent the 10-kHz SCS trial, 17 were successful and 14 subjects received permanent implants. No neurological deficits were observed in any subjects and all adverse events (AEs) were resolved without sequelae during the study period. Over 12 months, mean VAS scores decreased by 72% from baseline, and 10 of 13 subjects (77%) were responders (≥50% pain relief). Pain remission (VAS score ≤ 3.0 cm) was reported by 8 of 13 subjects (62%), and mean pain scores on the short-form McGill Pain Questionnaire 2 decreased as well. Pain Disability Index scores declined by 29 points, and 85% of the subjects reported satisfaction. CONCLUSIONS: Paresthesia-independent stimulation with 10-kHz SCS reduced pelvic pain in subjects with CPP and was not associated with any unexpected AEs. While larger, controlled studies are needed, results of this study suggest that this therapeutic modality could potentially treat patients with CPP while improving their quality of life.


Assuntos
Manejo da Dor/métodos , Dor Pélvica/terapia , Estimulação da Medula Espinal/métodos , Adulto , Dor Crônica/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Estudos Prospectivos , Qualidade de Vida , Resultado do Tratamento
19.
Pain Pract ; 21(8): 898-906, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34251751

RESUMO

BACKGROUND: The goal of this study was to demonstrate that the paresthesia-independent 10 kHz spinal cord stimulation (SCS) can provide long-term pain relief in patients with peripheral polyneuropathy (PPN). Clinically diagnosed subjects with PPN refractory to conventional medical management were enrolled in this prospective, multicenter study between November 2015 and August 2016, after institutional review board approval and patient informed consent were obtained. METHODS: Subjects underwent trial stimulation utilizing 2 epidural leads, and if successful, were implanted with a permanent 10 kHz SCS system and followed up for 12 months post-implant. Outcome measures included adverse events, pain, neurological assessments, disability, function, quality of life, pain interference, sleep, satisfaction, and global impression of change. Data are presented as descriptive statistics. Permanent implant population results are reported as mean ± standard error. RESULTS: Twenty-one of the 26 trialed subjects had a successful trial and 18 received a permanent implant. All subjects had the leads placed anatomically without the need for paresthesia. Subjects experienced significant and sustained pain relief (at least 65% at all timepoints) whereas physicians noted improvements in neurological function. Significant improvements in disability, function, sleep, sensory, and affective dimensions of pain were reported at all timepoints. All adverse events were resolved without sequelae. CONCLUSION: Findings from this study suggest that 10 kHz SCS may provide sustained pain relief and disability improvements in patients suffering from PPN.


Assuntos
Dor Crônica , Polineuropatias , Estimulação da Medula Espinal , Humanos , Projetos Piloto , Estudos Prospectivos , Qualidade de Vida , Medula Espinal , Resultado do Tratamento
20.
Pain Pract ; 21(8): 877-889, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34216103

RESUMO

BACKGROUND: The objective of this prospective, multicenter study is to characterize responses to percutaneous medial branch peripheral nerve stimulation (PNS) to determine if results from earlier, smaller single-center studies and reports were generalizable when performed at a larger number and wider variety of centers in patients recalcitrant to nonsurgical treatments. MATERIALS & METHODS: Participants with chronic axial low back pain (LBP) were implanted with percutaneous PNS leads targeting the lumbar medial branch nerves for up to 60 days, after which the leads were removed. Participants were followed long-term for 12 months after the 2-month PNS treatment. Data collection is complete for visits through end of treatment with PNS (primary end point) and 6 months after lead removal (8 months after start of treatment), with some participant follow-up visits thereafter in progress. RESULTS: Clinically and statistically significant reductions in pain intensity, disability, and pain interference were reported by a majority of participants. Seventy-three percent of participants were successes for the primary end point, reporting clinically significant (≥30%) reductions in back pain intensity after the 2-month percutaneous PNS treatment (n = 54/74). Whereas prospective follow-up is ongoing, among those who had already completed the long-term follow-up visits (n = 51), reductions in pain intensity, disability, and pain interference were sustained in a majority of participants through 14 months after the start of treatment. CONCLUSION: Given the minimally invasive, nondestructive nature of percutaneous PNS and the significant benefits experienced by participants who were recalcitrant to nonsurgical treatments, percutaneous PNS may provide a promising first-line neurostimulation treatment option for patients with chronic axial back pain.


Assuntos
Dor Lombar , Estimulação Elétrica Nervosa Transcutânea , Dor nas Costas/tratamento farmacológico , Humanos , Dor Lombar/terapia , Estudos Prospectivos , Resultado do Tratamento
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