Efficient molecular doping of polymeric semiconductors driven by anion exchange.

The efficiency with which polymeric semiconductors can be chemically doped-and the charge carrier densities that can thereby be achieved-is determined primarily by the electrochemical redox potential between the π-conjugated polymer and the dopant species1,2. Thus, matching the electron affinity of one with the ionization potential of the other can allow effective doping3,4. Here we describe a different process-which we term 'anion exchange'-that might offer improved doping levels. This process is mediated by an ionic liquid solvent and can be pictured as the effective instantaneous exchange of a conventional small p-type dopant anion with a second anion provided by an ionic liquid. The introduction of optimized ionic salt (the ionic liquid solvent) into a conventional binary donor-acceptor system can overcome the redox potential limitations described by Marcus theory5, and allows an anion-exchange efficiency of nearly 100 per cent. As a result, doping levels of up to almost one charge per monomer unit can be achieved. This demonstration of increased doping levels, increased stability and excellent transport properties shows that anion-exchange doping, which can use an almost infinite selection of ionic salts, could be a powerful tool for the realization of advanced molecular electronics.

Nitrogen-Containing Perylene Diimides: Molecular Design, Robust Aggregated Structures, and Advances in n-Type Organic Semiconductors.

ConspectusOrganic semiconductors (OSCs) have attracted much attention because of their potential applications for flexible and printed electronic devices and thus have been extensively investigated in a variety of research fields, such as organic chemistry, solid-state physics, and device physics and engineering. Organic thin-film transistors (OTFTs), a class of OSC-based devices, have been expected to be an alternative of silicon-based metal oxide semiconductor field-effect transistors (MOSFETs), which is the indispensable element for most of the current electronic devices. However, the noncovalently aggregated, van der Waals solid nature of the OSCs, by contrast to covalently bound silicon, conventionally exhibits lower carrier mobilities, limiting the practical applications of OTFTs. In particular, electron-transporting (i.e., n-type) OSCs lag behind their hole-transporting (p-type) counterparts in carrier mobility and ambient stability as OTFTs. This is primarily because of the difficulty in achieving compatibility between the aggregated structure exhibiting excellent carrier mobility and that with enough electron affinity. Recent understandings of carrier transport in OSCs explain that large and two-dimensionally isotropic transfer integrals coupled with small fluctuations are crucial for high carrier mobilities. In addition, from a practical point of view, the compatibility with practical device processes is highly required. Rational molecular design principles, therefore, are still demanded for developing OSCs and OTFTs toward high-end device applications.Herein, we will show our recent progress in the development of n-type OSCs with the key π-electron core (π-core) of benzo[de]isoquinolino[1,8-gh]quinolinetetracarboxylic diimide (BQQDI) on the basis of single-crystal OTFT technologies and the band-transport model enabled by two-dimensional molecular packing arrangements. The critical point is the introduction of electronegative nitrogen atoms into the π-core: the nitrogen atoms in BQQDI not only deepen the molecular orbital energies but also allow hydrogen-bonding-like attractive intermolecular interactions to control the aggregated structures, unlike the conventional role of the nitrogen introduced into OSCs only for the former role. Hence, the BQQDI analogues exhibit air-stable OTFT behavior and two-dimensional brickwork packing structures. Specifically, phenethyl-substituted analogue (PhC2-BQQDI) has been shown as the first principal BQQDI-based material, demonstrating solution-processable thin-film single crystals, fewer anisotropic transfer integrals, and an effective suppression of molecular motions, leading to band-like electron-transport properties and stress-durable n-channel OTFT performances, in conjunction with the support of computational calculations. Insights into more fundamental points of view have been found by side-chain derivatization and OTFT studies on polycrystalline and single-crystal films. We hope that this Account provides readers with new strategies for designing high-performance OSCs by two-dimensional control of the aggregated structures.

Individual and synergetic charge transport properties at the solid and electrolyte interfaces of a single ultrathin single crystal of organic semiconductors.

The chemical structures and morphologies of organic semiconductors (OSCs) and gate dielectrics have been widely investigated to improve the electrical performances of organic thin-film transistors (OTFTs) because the charge transport therein is a phenomenon at the semiconductor-dielectric interfaces. Here, solid and ionic gel gate dielectrics were adopted on the lower and upper surfaces, respectively, of a single, two molecule-thick single crystals of p-type OSCs to study the charge transport properties at individual interfaces between the morphologically compatible OSC surface and different gate dielectrics. Using the four-probe method, the solid and ionic gel interfaces were found to exhibit hole mobilities of 9.3 and 2.2 cm2 V-1 s-1, respectively, which revealed the crucial impact of the gate dielectric materials on the interfacial charge transport. Interestingly, when gate biases are applied through both dielectrics, i.e., under the solid/ionic gel dual-gate transistor operation, the hole mobility at the solid gate interface is improved up to 14.7 cm2 V-1 s-1, which is 1.5 times greater than that assessed without the ionic gel gate. This improvement can be attributed to the electric double layer formed at the ionic gel/uniform crystal surface, which provides a close-to-ideal charge transport interface through dramatic trap-filling. Therefore, the present dual-gate transistor technique will be promising for investigating the intrinsic charge-transport capabilities of OSCs.

High-performance, semiconducting membrane composed of ultrathin, single-crystal organic semiconductors.

Thin film transistors (TFTs) are indispensable building blocks in any electronic device and play vital roles in switching, processing, and transmitting electronic information. TFT fabrication processes inherently require the sequential deposition of metal, semiconductor, and dielectric layers and so on, which makes it difficult to achieve reliable production of highly integrated devices. The integration issues are more apparent in organic TFTs (OTFTs), particularly for solution-processed organic semiconductors due to limits on which underlayers are compatible with the printing technologies. We demonstrate a ground-breaking methodology to integrate an active, semiconducting layer of OTFTs. In this method, a solution-processed, semiconducting membrane composed of few-molecular-layer-thick single-crystal organic semiconductors is exfoliated by water as a self-standing ultrathin membrane on the water surface and then transferred directly to any given underlayer. The ultrathin, semiconducting membrane preserves its original single crystallinity, resulting in excellent electronic properties with a high mobility up to 12 [Formula: see text] The ability to achieve transfer of wafer-scale single crystals with almost no deterioration of electrical properties means the present method is scalable. The demonstrations in this study show that the present transfer method can revolutionize printed electronics and constitute a key step forward in TFT fabrication processes.

Electron-Deficient Benzo[de]isoquinolino[1,8-gh]quinoline Diamide π-Electron Systems.

Synthetically versatile electron-deficient π-electron systems are urgently needed for organic electronics, yet their design and synthesis are challenging due to the low reactivity from large electron affinities. In this work, we report a benzo[de]isoquinolino[1,8-gh]quinoline diamide (BQQDA) π-electron system. The electron-rich condensed amide as opposed to the generally-employed imide provides a suitable electronic feature for chemical versatility to tailor the BQQDA π-electron system for various electronic applications. We demonstrate an effective synthetic method to furnish the target BQQDA parent structure, and highly selective functionalization can be performed on bay positions of the π-skeleton. In addition, thionation of BQQDA can be accomplished under mild conditions. Fine-tuning of fundamental properties and supramolecular packing motifs are achieved via chemical modifications, and the cyanated BQQDA organic semiconductor demonstrates a high air-stable electron-carrier mobility.

Mixed-Orbital Charge Transport in N-Shaped Benzene- and Pyrazine-Fused Organic Semiconductors.

The hole-carrier transport of organic semiconductors is widely known to occur via intermolecular orbital overlaps of the highest occupied molecular orbitals (HOMO), though the effect of other occupied molecular orbitals on charge transport is rarely investigated. In this work, we first demonstrate evidence of a mixed-orbital charge transport concept in the high-performance N-shaped decyl-dinaphtho[2,3-d:2',3'-d']benzo[1,2-b:4,5-b']dithiophene (C10-DNBDT-NW), where electronic couplings of the second HOMO (SHOMO) and third HOMO (THOMO) also contribute to the charge transport. We then present the molecular design of an N-shaped bis(naphtho[2',3':4,5]thieno)[2,3-b:2',3'-e]pyrazine (BNTP) π-electron system to induce more pronounced mixed-orbital charge transport by incorporating the pyrazine moiety. An effective synthetic strategy for the pyrazine-fused extended π-electron system is developed. With substituent engineering, the favorable two-dimensional herringbone assembly can be obtained with BNTP, and the decylphenyl-substituted BNTP (C10Ph-BNTP) demonstrates large electronic couplings involving the HOMO, SHOMO, and THOMO in the herringbone assembly. C10Ph-BNTP further shows enhanced mixed-orbital charge transport when the electronic couplings of all three occupied molecular orbitals are taken into consideration, which results in a high hole mobility up to 9.6 cm2 V-1 s-1 in single-crystal thin-film organic field-effect transistors. The present study provides insights into the contribution of HOMO, SHOMO, and THOMO to the mixed-orbital charge transport of organic semiconductors.

Two-dimensional hole gas in organic semiconductors.

A highly conductive metallic gas that is quantum mechanically confined at a solid-state interface is an ideal platform to explore non-trivial electronic states that are otherwise inaccessible in bulk materials. Although two-dimensional electron gases have been realized in conventional semiconductor interfaces, examples of two-dimensional hole gases, the counterpart to the two-dimensional electron gas, are still limited. Here we report the observation of a two-dimensional hole gas in solution-processed organic semiconductors in conjunction with an electric double layer using ionic liquids. A molecularly flat single crystal of high-mobility organic semiconductors serves as a defect-free interface that facilitates two-dimensional confinement of high-density holes. A remarkably low sheet resistance of 6 kΩ and high hole-gas density of 1014 cm-2 result in a metal-insulator transition at ambient pressure. The measured degenerate holes in the organic semiconductors provide an opportunity to tailor low-dimensional electronic states using molecularly engineered heterointerfaces.

Lung thermography during the initial reperfusion period to assess pulmonary function in cellular ex vivo lung perfusion.

BACKGROUND: Thermography is a noninvasive technology to detect low temperatures in poorly circulated areas. In ex vivo lung perfusion (EVLP), lungs are rewarmed to body temperature during the initial 1 h. Currently, the effect of graft thermal changes during the rewarming phase on pulmonary function is unknown. In this study, we evaluated the correlation of lung surface temperature with physiological parameters, wet/dry ratio, and transplant suitability in Lund-type EVLP. METHODS: Fifteen pigs were divided into three groups: control group (no warm ischemia) or donation after circulatory death groups with 60 or 90 min of warm ischemia (n = 5, each). Thermal images of the lower lobes were continuously collected from the bottom of an organ chamber using infrared thermography throughout EVLP. RESULTS: At 8 min, lung surface temperatures of nonsuitable cases were significantly lower than in suitable cases (25.1 ± 0.6 vs. 27.8 ± 1.2°C, p < 0.001), while there was no difference in lung surface temperatures between the two groups at 0-4 min and 12-120 min. There was a significant negative correlation between lung surface temperatures at 8 min and wet/dry ratio at 2 h in the lower lobes (R = -0.769, p < 0.001, cutoff = 26°C, area under the curve = 1.0). A lung surface temperature of <26°C was significantly correlated with poor pulmonary function and transplant nonsuitability. CONCLUSION: A lung surface temperature of ≥26°C at 8 min is a good early predictor of transplant suitability in cellular EVLP and might be applicable in clinical EVLP.

Prone ex vivo lung perfusion protects human lungs from reperfusion injury.

BACKGROUND: We previously reported beneficial effects of prone positioning during ex vivo lung perfusion (EVLP) using porcine lungs. In this study, we sought to determine if prone positioning during EVLP was beneficial in human donor lungs rejected for clinical use. METHODS: Human double lung blocs were randomized to prone EVLP (n = 5) or supine EVLP (n = 5). Following 16 h of cold storage at 4°C and 2 h of cellular EVLP in either the prone or supine position. Lung function, compliance, and weight were evaluated and transplant suitability determined after 2 h of EVLP. RESULTS: Human lungs treated with prone EVLP had significantly higher partial pressure of oxygen/fraction of inspired oxygen (P/F) ratio [348 (291-402) vs. 199 (191-257) mm Hg, p = 0.022] and significantly lower lung weight [926(864-1078) vs. 1277(1029-1483) g, p = 0.037] after EVLP. 3/5 cases in the prone group were judged suitable for transplant after EVLP, while 0/5 cases in the supine group were suitable. When function of upper vs. lower lobes was evaluated, prone EVLP lungs showed similar P/F ratios and inflammatory cytokine levels in lower vs. upper lobes. In contrast, supine EVLP lungs showed significantly lower P/F ratios [68(59-150) vs. 467(407-515) mm Hg, p = 0.012] and higher tissue tumor necrosis factor alpha levels [100.5 (46.9-108.3) vs. 39.9 (17.0-61.0) ng/ml, p = 0.036] in lower vs. upper lobes. CONCLUSIONS: Prone lung positioning during EVLP may optimize the outcome of EVLP in human donor lungs, possibly by improving lower lobe function.

Establishing an economical and widely accessible donation after circulatory death animal abattoir model for lung research using ex vivo lung perfusion.

BACKGROUND: Ex vivo lung perfusion (EVLP), is a platform that allows simultaneous testing and treatment of the lungs. However, use of EVLP is costly and requires access to lab animals and accompanying facilities. To increase the use of EVLP for research, we developed a method to perform EVLP using abattoir procured lungs. Furthermore, we were also able to significantly decrease costs. METHODS: Six pair of lungs were procured from abattoir sheep. The lungs were then flushed and stored in ice for 3 h. A low-flow (20% of cardiac output) approach, a tidal volume of 6 ml/kg bodyweight and total perfusion time of 3 h were chosen. Perfusion fluids and circuits were self-made. Lung biopsies, perfusate collection, respiratory values, circulatory pressures were recorded and hourly blood gas analyses were performed. RESULTS: Mean pO2 remained stable from 60 min (49.3 ± 7.1 kPa) to 180 min (51.5 kPa ± 8.0), p = 0.66. Pulmonary artery pressure remained ≤15 mm Hg and the left atrial pressure remained between 3 and 5 mm Hg and peak respiratory pressures ≤20 cmH2 O. Lactate dehydrogenase increased from start (96.3 ± 56.4 U/L) to the end of perfusion (315.8 ± 85.0 U/L), p < 0.05. No difference was observed in ATP between procurement and post-EVLP, 129.7 ± 37.4 µmol/g protein to 132.0 ± 23.4 µmol/g, p = 0.92. CONCLUSIONS: Sheep lungs, acquired from an abattoir, can be ex vivo perfused under similar conditions as lab animal lungs with similar results regarding e.g., oxygenation and ATP restoration. Furthermore, costs can be significantly reduced by making use of this abattoir model. By increasing accessibility and lowering costs for experiments using lung perfusion, more results may be achieved in the field of lung diseases.

Airway Compromise in Mandibular Fracture.

ABSTRACT: Airway compromise is life threatening complication in the maxillofacial fracture. However, the incident of the airway compromise following mandibular fracture was little known. Maxillofacial fractures during the past 3 years from 2017 to 2020 were investigated retrospectively. There were 154 patients with maxillofacial fractures were noted in the past 3 years. Mandibular fractures accounted for 93% of the maxillofacial fracture. The most common cause of injury was falls (75%), followed by sports (12%). Of these, 3 cases (1.9%) needed an airway management at the time of initial treatment, and all were mandibular fractures. The average age was 55.7 ±â€Š10 years and all were male. The cause of the injury was high-energy trauma including traffic accident and work-related injury. Endotracheal intubation was performed at the time of initial treatment. All cases were communicated mandibular fracture included symphysis and para-symphysis region, and the bone fragments including the genial tubercle were largely displaced inward.

Low-Background Tip-Enhanced Raman Spectroscopy Enabled by a Plasmon Thin-Film Waveguide Probe.

Tip-enhanced Raman spectroscopy (TERS) is a nano-optical approach to extract spatially resolved chemical information with nanometer precision. However, in the case of direct-illumination TERS, which is often employed in commercial TERS instruments, strong fluorescence or far-field Raman signals from the illuminated areas may be excited as a background. They may overwhelm the near-field TERS signal and dramatically decrease the near-field to far-field signal contrast of TERS spectra. It is still challenging for TERS to study the surface of fluorescent materials or a bulk sample that cannot be placed on an Au/Ag substrate. In this study, we developed an indirect-illumination TERS probe that allows a laser to be focused on a flat interface of a thin-film waveguide located far away from the region generating the TERS signal. Surface plasmon polaritons are generated stably on the waveguide and eventually accumulated at the tip apex, thereby producing a spatially and energetically confined hotspot to ensure stable and high-resolution TERS measurements with a low background. With this thin-film waveguide probe, TERS spectra with obvious contrast from a diamond plate can be acquired. Furthermore, the TERS technique based on this probe exhibits excellent TERS signal stability, a long lifetime, and good spatial resolution. This technique is expected to have commercial potential and enable further popularization and development of TERS technology as a powerful analytical method.

Significance of Lung Weight in Cellular Ex Vivo Lung Perfusion.

BACKGROUND: Currently, pulmonary edema is evaluated via surgical inspection and palpation in donor lungs, and there is no quantitative standard diagnostic tool for evaluating pulmonary edema in donor procurement and ex vivo lung perfusion (EVLP). The purpose of this study was to investigate the significance of lung weight at the donor hospital and lung weight during EVLP as a complementary parameter of transplant suitability in EVLP. MATERIALS AND METHODS: Twenty-one of rejected human lungs were perfused in cellular EVLP. Transplant suitability was evaluated at 2 h as per standard criteria of Lund-protocol EVLP. RESULTS: Lung weight at donor hospital was significantly correlated with PaO2/FiO2 (P/F) ratio in EVLP (r = -0.44). There was a significant difference in lung weight at donor hospital between suitable cases (n = 13) and nonsuitable cases (n = 8). Light lung group (lung weight at donor hospital < 1280 g; n = 17) was suitable for transplant in 76%, whereas none of heavy lung group (lung weight at donor hospital ≥ 1280 g; n = 4) was suitable (P < 0.05). Lung weight at 2 h and lung weight change during EVLP were significantly associated with P/F ratio at 2 h and transplant suitability (P < 0.05, each). CONCLUSIONS: Our findings demonstrate that lung weight at donor hospital, lung weight change, and lung weight at 2 h of EVLP might be a predictor of P/F ratio and transplant suitability in cellular EVLP.

Accidental Insertion of a Piercing Needle in Tongue.

ABSTRACT: Tongue piercing causes various complications, including bleeding, pain and infection and it cause potential life-threatening complications. An 18-year-old woman presents with losing a needle in mouth. She attempted to perform tongue piercing using piercing needle by herself at home, and it was lost in mouth. The patient showed speech difficulty, but no active bleeding and edema of the floor of mouth. Computed tomography showed approximately 50 mm needle like structure in tongue. General anesthesia was performed with nasal intubation using video laryngoscope. The surgeon found the needle could be hold in the tongue by fingers. The needle in the tongue was holding by left fingers, and 10 mm skin incision was made by right hand. The needle tip was pushed to the incision line and it was removed. There was no bleeding immediate after needle removal. She could speak immediate after surgery. Two days after surgery, the patient discharged with no complications.

Mandibular Fracture in a Patient Taking a Direct Oral Anticoagulant.

ABSTRACT: A 74-year-old man presented with hemorrhage from the mandible after an injury caused by a 5 × 3 × 3-cm metal square column flying from a 45-ton press machine that struck the right side of his face. He is a known atrial fibrillation patient and is on rivaroxaban, a direct oral anticoagulant. An approximately 8-cm Y-shaped wound with persistent hemorrhage was observed in the right mandible, and the mandible was displaced between the right mandibular canine and first premolar. Although the patient showed no dyspnea, the sublingual region showed a slight dark purple swelling; fiberoptic nasal intubation was performed. Computed tomography at 3.5 hours after the injury revealed a comminuted fracture of the right mandibular body, edema at the floor of the mouth, nasal cavity, upper pharynx to hypopharynx, and the pharyngeal airway around the endotracheal tube. Open reduction and internal fixation were performed. Rivaroxaban was started again 3 days after surgery.

Efficacy of oral myofunctional therapy in middle-aged to elderly patients with obstructive sleep apnoea treated with continuous positive airway pressure.

BACKGROUND: Oral myofunctional therapy (MFT) is an effective treatment for mild-to-moderate obstructive sleep apnoea (OSA) in middle-aged patients. However, few reports have described its use in elderly patients with moderate and severe OSA. Moreover, no studies have examined the relationship between changes in tongue pressure with MFT and the severity of OSA. OBJECTIVE: We conducted an interventional study using MFT to evaluate the effect of MFT on middle-to-senior-aged patients with moderate or severe OSA and compared changes in apnoea-hypopnea index (AHI) and tongue pressure. METHODS: Thirty-two OSA patients (≥45 years) treated with continuous positive airway pressure (CPAP) were included. MFT was performed in parallel with CPAP. Three days after CPAP discontinuation, polysomnographies were performed and tongue pressures were measured before and after MFT. RESULTS: Patients were 69.3 ± 1.5 years old. After 6 months of MFT, AHI decreased significantly from 34.7 to 29.0/h (P = .03), while tongue pressure significantly increased from 35.9 to 45.6 kPa (P < .01). Seven patients (22%), including 6 of the 12 patients with moderate OSA (50%), experienced successful CPAP discontinuation. CONCLUSIONS: MFT can be a useful intervention even among middle-aged to elderly patients with OSA. Increased tongue pressure may have contributed to the AHI improvement. Clinical trials: Trial registration at www.umin.ac.jp UMIN000027547.

Manipulations of Chiroptical Properties in Belt-Persistent Cycloarylenes via Desymmetrization with Heteroatom Doping.

A desymmetrization strategy has been devised in the design of molecular cylinders to maximize the dissymmetry factor relevant to circularly polarized light. Although the highest dissymmetry factor of organic molecules was previously achieved with a chiral belt-persistent cycloarylene having magnetic and electric transition dipole moments in parallel, we noticed that an unbalanced magnitude of two moments was detrimental for higher dissymmetry factors. In this study, a molecular cylinder was desymmetrized by arraying doped and undoped panels via stereoselective cross-coupling macrocyclization. The desymmetrization succeeded in balancing two moments by reducing the electric transition moment at the global minimum but failed to maximize the dissymmetry factor. Structural studies revealed that the dissymmetry factor is sensitive to subtle structural fluctuations, while the rotatory strength is not affected. This study is important for the development of chiroptical materials.

Bent-Shaped p-Type Small-Molecule Organic Semiconductors: A Molecular Design Strategy for Next-Generation Practical Applications.

Significant progress has been made in both molecular design and fundamental scientific understanding of organic semiconductors (OSCs) in recent years. Suitable charge-carrier mobilities (µ) have been obtained by many high-performance OSCs (µ > 10 cm2 V-1 s-1), but drawbacks remain, including low solution processability and poor thermal durability. In addition, since aggregation of OSCs involves weak intermolecular interactions, the molecules are perpetually in thermal motion, even in the solid state, which disrupts charge-carrier transport. These issues limit potential applications of OSCs. The present work examines a molecular design for hole-transporting (p-type) OSCs based on the "bent-shaped" geometry with specific molecular orbital configurations, which aims to enhance effective intermolecular orbital overlaps, stabilize crystal phases, suppress detrimental molecular motions in the solid state, and improve solution processability. The results indicated that such OSCs have high µ and suitable solution processability, and are resistant to ambient and thermal conditions, making them suitable for practical applications.

Alkyl-Substituted Selenium-Bridged V-Shaped Organic Semiconductors Exhibiting High Hole Mobility and Unusual Aggregation Behavior.

Toward the development of high-performance organic semiconductors (OSCs), carrier mobility is the most important requirement for next-generation OSC-based electronics. The strategy is that OSCs consisting of a highly extended π-electron core exhibit two-dimensional (2D) aggregated structures to offer effective charge transport. However, such OSCs, in general, show poor solubility in common organic solvents, resulting in limited solution processability. This is a critical trade-off between the development of OSCs with simultaneous high carrier mobility and suitable solubility. To address this issue, herein, five-membered ring-fused selenium-bridged V-shaped binaphthalene with decyl substituents (C10-DNS-VW) is developed and synthesized by an efficient method. C10-DNS-VW exhibits significantly high solubility for solution processes. Notably, C10-DNS-VW forms a one-dimensional π-stacked packing motif (1D motif) and a 2D herringbone (HB) packing motif (2D motif), depending on the crystal growth condition. On the other hand, the fabrication of thin films by means of both solution process and vacuum deposition techniques forms only the 2D HB motif. External stress tests such as heating and exposure to solvent vapor indicated that 1D and 2D motifs could be synergistically induced by the total balance of intermolecular interactions. Finally, the single-crystalline films of C10-DNS-VW by solution process exhibit carrier mobility up to 11 cm2 V-1 s-1 with suitable transistor stability under ambient conditions for more than two months, indicating that C10-DNS-VW is one of the most promising candidates for breaking the trade-off in the field of solution-processed technologies.

Hyperinflation With Pulmonary Dysfunction in Donor Lungs With Smoking History During Lung Perfusion.

BACKGROUND: Donor lungs with smoking history are perfused in ex vivo lung perfusion (EVLP) to expand donor lung pool. However, the impact of hyperinflation of perfused lungs in EVLP remains unknown. The aim of this study was to investigate the significance of hyperinflation, using an ex vivo measurement delta VT, during EVLP in smoker's lungs. MATERIALS AND METHODS: Seventeen rejected donor lungs with smoking history of median 10 pack-years were perfused for 2 h in cellular EVLP. Hyperinflation was evaluated by measuring delta VT = inspiratory - expiratory tidal volume (VT) difference at 1 h. All lungs were divided into two groups; negative delta VT (n = 11, no air-trapping pattern) and positive delta VT (n = 6, air-trapping pattern). Transplant suitability was judged at 2 h. By using lung tissue, linear intercept analysis was performed to evaluate the degree of hyperinflation. RESULTS: The positive delta VT group had significantly lower transplant suitability than the negative delta VT group (16 versus 81%, P = 0.035). The positive delta VT group was significantly associated with lower partial pressure of oxygen/fraction of inspired oxygen ratio ratio (278 versus 356 mm Hg, P = 0.049), higher static compliance (119 versus 98 mL/cm H2O, P = 0.050), higher lung weight ratio (1.10 versus 0.96, P = 0.014), and higher linear intercept ratio (1.52 versus 0.93, P = 0.005) than the negative delta VT group. CONCLUSIONS: Positive delta VT appears as an ex vivo marker of ventilator-associated lung hyperinflation of smoker's lungs during EVLP.