In implantable bioelectronics, which aim for semipermanent use of devices, biosafe energy sources and packaging materials to protect devices are essential elements. However, research so far has been ...conducted in a direction where they cannot coexist. Here, the development of capacitance‐matched triboelectric implants driven is reported by ultrasound under 500 mW cm−2 safe intensity and realize a battery‐free, miniatured, and wireless neurostimulator with full titanium (Ti) packaging. The triboelectric implant with high dielectric composite, which has ultralow output impedance, can efficiently deliver sufficient power to generate the stimulation pulse without an energy‐storing battery, despite ultrasound attenuation due to the Ti, and has the highest energy transmission efficiency among those reported so far. In vivo study using a rat model demonstrated that the proposed device system is an effective solution for relieving urinary symptoms. These achievements provide a significant step toward permanently implantable devices for controlling human organs and treating various diseases.
The ultrasound‐driven triboelectric nanogenerator using a high‐dielectric composite not only improves the output of the device, but also improves the connectivity between the energy harvester and the circuit, enabling the semipermanent use and miniaturization of implantable medical devices. These triboelectric implants provide a significant step toward permanently implantable devices for controlling human organs and treating various diseases.
Abstract Bioresorbable bioelectronics, with their natural degradation properties, hold significant potential to eliminate the need for surgical removal. Despite notable achievements, two major ...challenges hinder their practical application in medical settings. First, they necessitate sustainable energy solutions with biodegradable components via biosafe powering mechanisms. More importantly, reliability in their function is undermined by unpredictable device lifetimes due to the complex polymer degradation kinetics. Here, we propose an on-demand bioresorbable neurostimulator to address these issues, thus allowing for clinical operations to be manipulated using biosafe ultrasound sources. Our ultrasound-mediated transient mechanism enables (1) electrical stimulation through transcutaneous ultrasound-driven triboelectricity and (2) rapid device elimination using high-intensity ultrasound without adverse health effects. Furthermore, we perform neurophysiological analyses to show that our neurostimulator provides therapeutic benefits for both compression peripheral nerve injury and hereditary peripheral neuropathy. We anticipate that the on-demand bioresorbable neurostimulator will prove useful in the development of medical implants to treat peripheral neuropathy.
Consecutive case series with prospective data collection.
To define and analyze the learning curve for minimally invasive transforaminal lumbar interbody fusion (TLIF).
Minimally invasive TLIF using ...a unilateral approach has recently been gaining popularity because of its potential for minimizing soft-tissue damage and reducing recovery time. However, a steep learning curve has been described for surgeons first performing this technique.
Eighty-six consecutive patients with degenerative lumbar diseases who were treated by TLIF were included in the study. Surgeries were performed using a tubular retractor, and a cage was inserted using a unilateral transforaminal approach by a single surgeon. The corresponding segments were fixed with percutaneous pedicle screws. Eighty-three patients were followed up for more than 1 year, and the average follow-up period was 25 months. Single-level TLIF was performed in 60 cases, single-level TLIF plus adjacent-level decompression was performed in 13 cases, and double-level TLIF was performed in 13 cases. Corrected operative time per level, operative blood loss, postoperative blood drainage, total blood loss, and ambulation recovery time were measured. Transfusion rates and complication incidence were also identified. Clinical results were assessed using the Oswestry Disability Index (ODI) and a visual analogue scale (VAS). The learning curve was assessed using a logarithmic curve-fit regression analysis. In the single-level TLIF group (n = 60), 22 patients were defined as the "early" group (among the first 30 cases of the series), and the subsequent 38 cases were defined as the "late" group for comparison.
Corrected operative time gradually decreased as the series progressed, and an asymptote was reached after about 30 cases. ODI significantly decreased from an average of 24 at the preoperative stage to 10 at the final follow-up. Average VAS scores for lower back pain and radiating pain also significantly decreased from an average of 5.2 to 1.9 and 6.8 to 0.9, respectively. In the single-level TLIF series, operative time was significantly shorter in the late group (183 ± 23 min) than the early group (254 ± 44 min), and blood loss during the operation was significantly reduced in the late group (292 ± 280 mL) compared with the early group (508 ± 278 mL). Ambulation recovery time significantly decreased from 2.4 ± 0.6 days in the early group to 2.0 ± 0.5 in the late group. ODI and VAS scores for lower back pain and radiating pain did not differ between the 2 groups.
Although it is not easy to master the minimally invasive TLIF technique, the surgeon's experience with this operation correlated with reduced operation time and blood loss during surgery. After the initial learning curve, this technique could be an effective and reliable option for the surgical treatment of lumbar degenerative disease.
Lead‐(Pb‐) halide perovskite nanocrystals (NCs) are interesting nanomaterials due to their excellent optical properties, such as narrow‐band emission, high photoluminescence (PL) efficiency, and wide ...color gamut. However, these NCs have several critical problems, such as the high toxicity of Pb, its tendency to accumulate in the human body, and phase instability. Although Pb‐free metal (Bi, Sn, etc.) halide perovskite NCs have recently been reported as possible alternatives, they exhibit poor optical and electrical properties as well as abundant intrinsic defect sites. For the first time, the synthesis and optical characterization of cesium ytterbium triiodide (CsYbI3) cubic perovskite NCs with highly uniform size distribution and high crystallinity using a simple hot‐injection method are reported. Strong excitation‐independent emission and high quantum yields for the prepared NCs are verified using photoluminescence measurements. Furthermore, these CsYbI3 NCs exhibit potential for use in organic–inorganic hybrid photodetectors as a photoactive layer. The as‐prepared samples exhibit clear on–off switching behavior as well as high photoresponsivity (2.4 × 103 A W−1) and external quantum efficiency (EQE, 5.8 × 105%) due to effective exciton dissociation and charge transport. These results suggest that CsYbI3 NCs offer tremendous opportunities in electronic and optoelectronic applications, such as chemical sensors, light emitting diodes (LEDs), and energy conversion and storage devices.
The rare‐earth element ytterbium (Yb) is substituted into the B site of a cubic ABX3 perovskite lattice in place of lead. The resulting CsYbI3 nanocrystals exhibit strong excitonic emission with high quantum yield and the potential for use in hybrid photodetectors as a photoactive layer. Such lead‐free CsYbI3 nanocrystals offer tremendous opportunities in optical and optoelectronic applications.
Particle size distributions (PSDs) of suspended particulate matters in a coastal zone are lognormal and multimodal in general. The multimodal PSD, which is caused by the mixing of multiple particle ...and aggregate size groups under flocculation and erosion/resuspension, is a record of the particle and aggregate dynamics in a coastal zone. Curve‐fitting software was used to decompose the multimodal PSD into subordinate lognormal PSDs of primary particles, flocculi, microflocs, and macroflocs. The curve‐fitting analysis for a time series of multimodal PSDs in the Belgian coastal zone showed the dependency of the multimodality on (1) shear‐dependent flocculation in a flood and ebb tide, (2) breakage‐resistant flocculation in the spring season, and (3) silt‐sized particle erosion and advection in a storm surge. Also, for modeling and simulation purposes, the curve‐fitting analysis and the settling flux estimation for the multimodal PSDs showed the possibility of using discrete groups of primary particles, flocculi, microflocs, and macroflocs as an approximation of a continuous multimodal PSD.
Key Points
Decomposition of the multimodal PSDs to the subordinate unimodal lognormal PSDs
Investigation on particle/floc dynamics in a coastal zone
Identification of primary particles, flocculi, microflocs, and macroflocs
Herein, we developed a fully solution-deposited nanocomposite photoanode based on silver nanoparticle (NP)-impregnated bismuth vanadate (BiVO4) films. The synthesized Ag NPs exhibit diameters of few ...nanometers and uniform matrix dispersion, which were confirmed by high-resolution transmission electron microscopy. The photoanode composed of the Ag NP-incorporated nanocomposite BiVO4 showed a remarkable enhancement in both low potential and the saturated photocatalytic current densities in comparison with the pristine BiVO4 film. The observed experimental results are attributed to the improved carrier generation and enhanced charge separation by the localized surface plasmon resonance-mediated effect as suggested by electrochemical impedance spectroscopy and a numerical simulation.
Background
Two-stage tissue expander/implant-based method has been used predominantly for breast reconstruction. Implant rupture is one of the bothersome complications, inducing additional morbidity ...including reoperation. The present study aimed to identify the independent factors associated with development of implant rupture.
Patients and Methods
Patients who underwent immediate two-stage prosthetic breast reconstruction between 2010 and 2016 were reviewed. Inserted implants were followed up using magnetic resonance imaging every 2 years and/or ultrasound/computed tomography scans every 6 or 12 months that were conducted for cancer surveillance. Associations of perioperative and intraoperative variables with the development of implant rupture were evaluated.
Results
In total, 797 cases (744 patients) were analyzed. During a median follow-up of 43 months after second-stage operation, implant rupture was identified in 22 cases. The 5-year cumulative incidence was 3.1%. Multivariable analyses showed that the interval between the first- and second-stage operations was inversely associated with the risk of implant rupture. Maximal discrimination was observed at the interval of 6.5 months. Cases with an interval ≤ 6 months were associated with higher risks for implant rupture than those with ≥ 7 months, after adjusting for other variables. Type of implant was associated with the development of implant rupture, showing that using two kinds of fourth-generation implant (Allergan Biocell textured round and Allergan smooth round implants) was associated with a significantly increased risk of implant rupture compared with that of Mentor MemoryShape implants (fifth-generation implant).
Conclusion
Several operation-related variables appear to be associated with implant rupture in two-stage prosthetic reconstruction.
Abstract
Photophysical and photochemical properties of graphene quantum dots (GQDs) strongly depend on their morphological and chemical features. However, systematic and uniform manipulation of the ...chemical structures of GQDs remains challenging due to the difficulty in simultaneous control of competitive reactions, i.e., growth and doping, and the complicated post-purification processes. Here, we report an efficient and scalable production of chemically tailored N-doped GQDs (NGs) with high uniformity and crystallinity via a simple one-step solvent catalytic reaction for the thermolytic self-assembly of molecular precursors. We find that the graphitization of N-containing precursors during the formation of NGs can be modulated by intermolecular interaction with solvent molecules, the mechanism of wh ich is evidenced by theoretical calculations and various spectroscopic analyses. Given with the excellent visible-light photoresponse and photocatalytic activity of NGs, it is expected that the proposed approach will promote the practical utilization of GQDs for various applications in the near future.
The hydrophobicity of dissolved organic matter (DOM) affects various aspects of its environmental impacts in terms of water quality, sorption behaviors, interactions with other pollutants, and water ...treatment efficiency. In this study, source tracking of river DOM was conducted separately for hydrophobic acid (HoA-DOM) and hydrophilic (Hi-DOM) fractions using end-member mixing analysis (EMMA) in an agricultural watershed during a storm event. EMMA with optical indices of bulk DOM revealed larger contributions of soil (24 %), compost (28 %), and wastewater effluent (23 %) to riverine DOM under high versus low flow conditions. Molecular level analysis of bulk DOM revealed more dynamic features, showing an abundance of CHO and CHOS formulae in riverine DOM under high- and low flow conditions. CHO formulae originated from soil (78 %) and leaves (75 %) and contributed to the increasing CHO abundance during the storm event, whereas CHOS formulae likely originated from compost (48 %) and wastewater effluent (41 %). The characterization of bulk DOM at the molecular level demonstrated that soil and leaves are the dominant contributors for the high-flow samples. However, in contrast to the results of bulk DOM analysis, EMMA with HoA-DOM and Hi-DOM revealed major contributions from manure (37 %) and leaf DOM (48 %) during storm events, respectively. The results of this study highlight the importance of individual source tracking of HoA-DOM and Hi-DOM for the proper evaluation of the ultimate roles of DOM in affecting river water quality and for a better understanding of DOM dynamics and transformation in natural and engineered systems.
Display omitted
•Source tracking was separately conducted for HoA- and Hi-DOM during a storm event.•Major sources were different between the HoA- and Hi-DOM in agricultural watershed.•Leaves were the major source contributor to Hi-DOM, whereas manure was to HoA-DOM.
BACKGROUND:A closed-suction drain is usually inserted during tissue expander–based breast reconstruction. Prolonged duration of drain retention can disturb patients’ daily lives and affect overall ...sociomedical costs. This study aimed to investigate factors that may influence the drainage and to identify predictors of unusually prolonged drain duration.
METHODS:Patients who underwent delayed-immediate, two-stage breast reconstruction using a tissue expander between January of 2013 and July of 2017 were reviewed. Prolonged drain duration was defined as drain duration for longer than the 75th percentile of that for the entire cohort. Effects of patient- and operation-related variables on drainage and prolonged drain duration were evaluated.
RESULTS:A total of 1056 cases (1002 patients) were analyzed. The median drain duration was 10 days. Drain placement for more than 12 postoperative days was observed in 256 cases (24.2 percent), classified as prolonged drain duration. Multivariate analyses demonstrated that old age, high body mass index, neoadjuvant chemotherapy, insertion of large Siltex textured tissue expanders, and greater volume of initial inflation were independent risk factors of prolonged drain duration. The size and texture of the tissue expanders and initial inflation volume retained their influence, regardless of mastectomy specimen weight. Use of acellular dermal matrix had contradictory effects according to breast size, being protective against prolonged drain duration in cases with mastectomy specimen weight greater than 400 g, and being a significant predictor for it in cases with mastectomy specimen weight less than or equal to 400 g.
CONCLUSION:Several factors, including reconstructive operation-related factors, might influence drain duration following tissue expander–based breast reconstruction.
CLINICAL QUESTION/LEVEL OF EVIDENCE:Risk, III.
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