Gas Exchange Capacity Research Articles

The Effects of Diabetes on Gas Transfer Capacity, Lung Volumes, Muscle Strength, and Cardio-pulmonary Responses During Exercise.

Diabetes is a risk factor for the development of vascular disease, chronic kidney disease, retinopathy, and neuropathy. Diabetes is a co-morbid condition commonly present in patients with respiratory disorders but the extent to which it influences ventilatory capacity, gas exchange, and functional capacity is not well known. Research question Does the presence of diabetes contribute to impairment in spirometry, gas transfer, and exercise capacity? Retrospective analysis of all subjects who performed incremental cardio-pulmonary exercise testing (CPET) between 1988 and 2012 at McMaster University Medical Centre. The impact of diabetes on physiological outcomes and maximum power output (MPO) was assessed using stepwise multiple additive linear regression models including age, height, weight, sex, muscle strength, and previous myocardial infarct as co-variates, and was also stratified based on BMI categories. 40,776 subjects were included in the analysis; 1938 (5%, 66% male) had diabetes. Diabetics were older (59 vs. 53 years), heavier (88.3 vs.78.0 kg), and had a higher BMI (31 vs. 27kg/m2). The presence of diabetes was independently associated with a reduction in FEV1 (-130ml), FVC (-220ml), DLCO (-1.52ml/min/mmHg), and VA (-340ml) but not KCO. Patients with diabetes achieved a lower % predicted MPO[diabetic subjects 70% predicted (670 kpm/min ± 95% CI 284) vs. 80% in non-diabetics (786 kpm/min ± 342), p < 0.001]. With the exception of KCO, these differences persisted across BMI categories and after adjusting for MI. The presence of diabetes is independently associated with weaker muscles, lower ventilatory and gas transfer capacity and translates to a lower exercise capacity. These differences are independent of age, height, weight, sex, and previous MI.

Effects of Salinity on ‘Fino 95’ Lemon Trees Inoculated with Arbuscular Mycorrhizal Fungi

An experiment was conducted with two-year-old ‘Fino 95’ lemon plants (Citrus limon Burm. f. cv. Fino) grafted on C. macrophylla (Citrus macrophylla Wester) to study the effects of salinity on plants inoculated with arbuscular mycorrhizal fungi (AMF). Half of the inoculated (+AM) and non-inoculated (−AM) plants were irrigated with half-strength Hoagland solution, and the remainder were inoculated with half-strength Hoagland solution + 30 mM NaCl. Ninety-eight days later, results showed that AMF had alleviated the negative effect of salinity on growth. Inoculation with AMF provided some protection against the damage that salinity caused on cellular membranes and improved the plant water status and turgor under saline conditions (Ψx and Π increased by 16% and 48%, respectively). The responses of mineral nutrition to salinity and AMF treatments were complex. P concentrations in the leaves and roots of +AM plants were lower than in those of −AM plants, but inoculation improved Ca2+ (by 20%), Mg2+ (24%), Fe2+ (21%), and Zn2+ (7%) nutrition in roots and also the Mg2+/Na+ ratio in leaves (33%), reducing the antagonistic effect of Na+ on Mg2+ nutrition in salt-treated plants. AMF could protect plants against salt stress through the maintenance of the gas exchange capacity and due to a better antioxidant response. All these positive effects of AMF contributed to mitigating the harmful effects of salinity stress on the plant growth performance of lemon trees grafted on C. macrophylla rootstock under salinity conditions.

Application of deep learning for the analysis of stomata: a review of current methods and future directions.

Plant physiology and metabolism rely on the function of stomata, structures on the surface of above-ground organs that facilitate the exchange of gases with the atmosphere. The morphology of the guard cells and corresponding pore that make up the stomata, as well as the density (number per unit area), are critical in determining overall gas exchange capacity. These characteristics can be quantified visually from images captured using microscopy, traditionally relying on time-consuming manual analysis. However, deep learning (DL) models provide a promising route to increase the throughput and accuracy of plant phenotyping tasks, including stomatal analysis. Here we review the published literature on the application of DL for stomatal analysis. We discuss the variation in pipelines used, from data acquisition, pre-processing, DL architecture, and output evaluation to post-processing. We introduce the most common network structures, the plant species that have been studied, and the measurements that have been performed. Through this review, we hope to promote the use of DL methods for plant phenotyping tasks and highlight future requirements to optimize uptake, predominantly focusing on the sharing of datasets and generalization of models as well as the caveats associated with utilizing image data to infer physiological function.

Effects of Long-Term High Temperatures in the Root Zone on the Physiological Characteristics of Grapevine Leaves and Roots: Implications for Viticulture Practices

Ridging cultivation and root restriction cultivation are beneficial due to their improvement of the soil permeability in the root zone of grapevine, and they are widely used in southern China, Japan, and other countries. However, with the intensification of global warming, when using ridging or root restriction cultivation, the soil temperature in the root zone can often reach 30 °C or even more than 35 °C during the summer, which is not conducive to the growth of grapevines. The aim of this study was to explore the effects of high root zone temperatures on the photosynthetic fluorescence characteristics of grapevine leaves, root respiration, and degree of lignification of roots and shoots, as well as to provide a theoretical foundation for the management of grapevine production and cultivation. One-year-old potted ‘Kyoho’ was used as the study material. Three root temperature treatments were implemented for 15 days (9:00–16:00): 25 °C (CK), 30 °C (T1), and 35 °C (T2). The results showed that the malondialdehyde and H2O2 levels in leaves increased, while the chlorophyll content decreased. The oxygen-evolving complex was inactivated, and PSII donor and acceptor sides were blocked, thus reducing the photosynthetic gas exchange capacity at high root zone temperatures. The grapevine root activity and root/shoot ratio decreased. Simultaneously, the lignin content in the roots and shoots increased. In addition, there was a significant increase in the expression of key genes (PAL, C4H, 4CL, F5H, COMT, CCR, and CAD) in the root lignin synthesis pathway. Heightened root zone temperatures increased cyanide-resistant respiration in roots and heat release in the PPP pathway to alleviate stress damage. Therefore, it is recommended to use grass, mulching, and other cultivation management methods to maintain root zone temperatures below 30 °C in order to ensure the normal growth of grapevines and promote a high and stable yield.

Outcomes of oncological intended thoracic surgery after lung transplantation.

Lung cancer following lung transplantation (LT) may require thoracic surgery (TS). There is an urgent need for data on surgical feasibility, clinical and surgical characteristics, as well as outcome data. We reviewed the medical records of LT patients who had undergone TS at the University Hospital Leipzig between the years 2000 and 2022. Data on medical and surgical history, pulmonary function test, arterial blood gas analysis, six-minute walking distance test, and surgical approach, perioperative management, anesthesiologic, and surgical procedures were analyzed. Among 248 LT patients, 13 patients (5.2%) developed lung cancer after 4.2 years on average and on 6 of them (46.2%), major TS procedure was performed for the resection of lung cancer. In one patient who underwent TS for a suspicious pulmonary nodule, it turned out to be a parenchymal scar. TS was carried out in 57.1% on the native lung and 42.9% on the transplant lung. Pneumonia and acute renal failure were predominantly observed postoperative complications. We found that the capacity of gas exchange either before or after TS was related to the degree of postoperative complications. The in-hospital survival was 71.4%. Incidence of lung cancer is increased after LT. Follow-up care allows early diagnosis with a comparably high share of operable tumor stage. Cancer as well as postoperative complications were more likely after single lung transplantation (SLT). Postoperative morbidity and mortality are higher in this scarce group of patients and hence, warrants a centered and experienced interdisciplinary approach.

Integrated physio-biochemical and transcriptomic analyses reveal the mechanism underlying ABA-mediated alleviation of salt stress in Limonium bicolor seedlings

Abscisic acid (ABA) plays an important role in regulating plant stress responses. However, there are currently no reports on ABA in regulating the salt tolerance of Limonium bicolor. Here, we analyzed the effects of exogenous ABA on growth, photosynthesis, salt secretion, and physiological and transcriptome changes of L. bicolor seedlings under 300 mM NaCl. Exogenous 10 µM ABA treatment in L. bicolor seedlings treated with salt upregulated the expression of genes related to stomatal development, increased the density and number of stomata, and improved plant gas exchange capacity, thereby increasing the net photosynthesis rate. Exogenous ABA treatment in L. bicolor seedlings under salt stress also upregulated the expression of genes related to salt gland development, promoted salt glands development, increased salt glands density, increased the salt secretion capacity of leaves, and reduced the accumulation of Na+ in the plant. ABA application enhanced salt tolerance of L. bicolor seedlings by increasing content of soluble solutes, enhancing antioxidant enzymes activities, decreasing accumulation of reactive oxygen species, and increasing ABA and indole acetic acid contents. Transcriptome sequencing revealed that genes differentially expressed in L. bicolor seedlings during ABA-induced salt tolerance are involved in many metabolic pathways, including plant hormone signal transduction, proline metabolism, endocytosis and protein processing in the endoplasmic reticulum. Furthermore, some transcription factors, MYB, bHLH, and WRKY, might contribute to the improved salt stress tolerance of L. bicolor conferred by ABA. These results provide a basis for further clarifying the salt tolerance mechanism mediated by exogenous ABA in L. bicolor seedlings.

Leaf photosynthetic performance is not a key factor affecting grain yield in spring wheat subjected to heat and combined heat and drought stresses

AbstractThe yield traits and physiological responses of three wheat genotypes were studied when subjected to heat and combined heat and drought stress at anthesis under either aCO2 (400 ppm) or eCO2 (800 ppm) in a greenhouse. The heat treatment was 7‐days at day/night 35/28°C, and the combined heat and drought was withholding irrigation from the heat‐stressed plants until the photosynthetic rate reached &lt;5 μmol m−2 s−1. The LM62 genotype had higher photosynthetic rate compared with LM19, though no significant difference in grain yield was found. eCO2 increased photosynthesis at 35°C and significantly lowered the electron transport rate at high intercellular CO2 concentrations. Maximum velocity of Rubisco carboxylation (Vcmax) and the maximum velocity of RuBP regeneration in leaves (Jmax) increased in 35°C compared with 25°C, though when normalized to 25°C both Vcmax and Jmax decreased in the heat‐stressed plants, indicating that an inhibition had occurred. The maximum photochemical efficiency of photosystem II (Fv/Fm) decreased under heat, which correlated with the yield loss caused by the stress. Fv/Fm also decreased under combined heat and drought, though it did not related to the declined yield. A small leaf area prolonged the drying period of Gladius, and it was the genotype with the lowest decrease in yield because of stress. It is concluded that the effects of heat and combined heat and drought stress on the gas exchange and photosynthetic capacity on leaf area basis are not directly linked to the yield performance among wheat genotypes, while the morphological characteristics of the plants are important determinants of grain yield in response to those abiotic stresses.

Drought Stress Alleviator Melatonin Reconfigures Water-Stressed Barley (Hordeum vulgare L.) Plants' Photosynthetic Efficiency, Antioxidant Capacity, and Endogenous Phytohormone Profile.

The production of crops is severely limited by water scarcity. We still do not fully understand the underlying mechanism of exogenous melatonin (MT)-mediated water stress tolerance in barley. This study is the first of its kind to show how MT can potentially mitigate changes in barley's physio-biochemical parameters caused by water deficiency. Barley was grown under three irrigation levels (100%, 70%, and 30% of field capacity) and was foliar sprayed with 70 μM MT. The results showed that exogenously applied MT protected the photosynthetic apparatus by improving photosynthetic pigment content, photochemical reactions of photosynthesis, Calvin cycle enzyme activity, gas exchange capacity, chlorophyll fluorescence system, and membrane stability index. Furthermore, the increased levels of salicylic acid, gibberellins, cytokinins, melatonin, and indole-3-acetic acid, as well as a decrease in abscisic acid, indicated that foliar-applied MT greatly improved barley water stress tolerance. Additionally, by increasing the activity of antioxidant enzymes such as superoxide dismutase, catalase, ascorbate peroxidase, monodehydroascorbate reductase, dehydroascorbate reductase, and glutathione reductase and decreasing hydrogen peroxide content, lipid peroxidation, and electrolyte leakage, MT application lessened water stress-induced oxidative stress. According to the newly discovered data, MT application improves barley water stress tolerance by reprogramming endogenous plant hormone production and antioxidant activity, which enhances membrane stability and photosynthesis. This study unraveled MT's crucial role in water deficiency mitigation, which can thus be applied to water stress management.

An Inverse Scaling Relationship between Stomatal Density and Mean Nearest Neighbor Distance: Evidence from a Photinia Hybrid and One of Its Parents.

Stomata are involved in transpiration and CO2 uptake by mediating gas exchange between internal plant tissues and the atmosphere. The capacity for gas exchange depends on stomatal density (SD), stomatal size, and pore dimensions. Most published work on stomatal quantification has assumed that stomatal distribution and stomatal density are spatially homogeneous across the leaf, but this assumption has been seldom tested. We selected 32 leaves from a Photinia hybrid, Photinia × fraseri 'Red Robin', and one of its parents, P. serratifolia. For each leaf, the leaf surface was divided into three or four equidistant layers along the apical-basal axis, and, in each layer, two positions, one closer to the midrib and the other closer to the leaf margin, were further selected. We calculated SD and mean nearest neighbor distance (MNND) for each lamina section and tested the scaling relationship between SD and MNND of the sampled stomatal centers using reduced major axis protocols. In addition, we calculated the stomatal aggregation index (SAI) for each lamina section to examine the spatial arrangement of stomata at the given size of field of view of 1.2 mm × 0.9 mm. We observed that SD decreased from the lamina apex towards the base for central lamina areas but varied little at leaf margins. An inverse scaling relationship between SD and MNND was observed for both species. This relationship could be used for SD estimation using the rapidly estimated trait, MNND. SAI did not vary significantly throughout leaf lamina, and the numerical values of SAI for all fields of view were greater than one, which indicates significant spatial repulsion between stomata. The study suggests that SD varies across leaf lamina to fine-tune plant water use and maximize carbon gain. However, spatial structures of stomata from different lamina sections exhibit similar patterns (i.e., spatial inhibition between stomata at small scales), probably due to hierarchical leaf vein patterns.

Flow and mass transfer prediction in anisotropic TPMS-structures as extracorporeal oxygenator membranes using reduced order modeling

Currently, hollow fiber membranes are the standard technology for extracorporeal membrane oxygenators. Apart from the inevitable contact of the circulating blood with the artificial material, a suboptimal flow distribution within the oxygenator favors thrombus formation which leads to a rapid loss of gas exchange capacity. The current advancement in additive manufacturing allows the design of three-dimensional membrane-structures, based on triply periodic minimal surfaces (TPMS). One of their unique advantages is local geometry variation to manipulate the flow distribution. But how this anisotropy influences the overall device performance is non-trivial and requires numerical simulation. The aim of this study was to develop a reduced order model (ROM) that is able to efficiently predict three-dimensional flow distribution and gas transfer inside TPMS-structures. We performed a parametric study using a validated micro scale computational fluid dynamics (CFD) model. Afterwards, two different modeling approaches of Sherwood-correlations and artificial neural networks (NN) were compared to characterize flow and mass transfer from the simulated data. To create the ROM, the NN modeling strategy was then implemented into a porous medium CFD model. The developed ROM was also validated. Finally, an anisotropic TPMS-membrane-structure was compared numerically with an isotropic predicate. The NN fitting strategy showed superior accuracy over the Sherwood-correlations for characterizing mass transfer in TPMS-structures. With the ROM, the gas transfer rates of oxygen and carbon dioxide from the micro CFD model could be predicted within relative root mean squared errors (RRMSE) of 2.7% and 5.1%. The pressure drop in the experiments was predicted with an RRMSE accuracy of 7.6%. In comparison with the isotropic TPMS-structure, the anisotropic structure showed a homogenized flow distribution and increased gas transfer rates of 4% to 5% for oxygen and 2.3% to 7.4% for carbon dioxide at the simulated flow rates.

The alveolar-capillary unit in the physiopathological conditions of heart failure: identification of a potential marker.

In this review, we describe the structure and function of the alveolar-capillary membrane and the identification of a novel potential marker of its integrity in the context of heart failure (HF). The alveolar-capillary membrane is indeed a crucial structure for the maintenance of the lung parenchyma gas exchange capacity, and the occurrence of pathological conditions determining lung fluids accumulation, such as HF, might significantly impair lung diffusion capacity altering the alveolar-capillary membrane protective functions. In the years, we found that the presence of immature forms of the surfactant protein-type B (proSP-B) in the circulation reflects alterations in the alveolar-capillary membrane integrity. We discussed our main achievements showing that proSP-B, due to its chemical properties, specifically binds to high-density lipoprotein, impairing their antioxidant activity, and likely contributing to the progression of the disease. Further, we found that immature proSP-B, not the mature protein, is related to lung abnormalities, more precisely than the lung function parameters. Thus, to the list of the potential proposed markers of HF, we add proSP-B, which represents a precise marker of alveolar-capillary membrane dysfunction in HF, correlates with prognosis, and represents a precocious marker of drug therapy.

Responses of salicylic acid encapsulation on growth, photosynthetic attributes and ROS scavenging system in Lactuca sativa exposed to polycyclic aromatic hydrocarbon pollution

Salicylic acid (SA) is a phytohormone that plays a key role in the regulation of the defense response against environmental variables in plants, and it provides increased yield and stress tolerance when exogenously applied to plants as a growth regulator. The role of SA-mediated signals in abiotic stress tolerance varies according to the species, stressor, application method, and dose. This study investigated the effects of salicylic acid (SA, 0.1 mg ml−1) or β-cyclodextrin encapsulated salicylic acid (e-SA, 0.1 mg ml−1) treatments on growth parameters, gas exchange, photosynthesis efficiency, and antioxidant capacity in lettuce seedlings exposed to polycyclic aromatic hydrocarbon pollution. Fluorene (FLN, 100 mg L−1) contamination resulted in a 27% growth rate and a 14% water content reduction in lettuce leaves. Significant suppressions of stomatal conductance, carbon assimilation, and PSII photochemistry were detected in plants under stress. FLN + SA and FLN + e-SA treatments regulated plant-water relations by stimulating proline accumulation and relieving stomatal limitations. As indicated by the high Fv/Fm ratio, photosynthesis efficiency was recovered in FLN + SA and FLN + e-SA group plants. FLN stress caused high oxidative stress in lettuce leaves and increased lipid peroxidation level by 40%. However, especially e-SA application to plants under stress, increased SOD activity by 3-fold and CAT activity by 80% and was successful in preventing H2O2 accumulation and lipid peroxidation. Both SA and e-SA treatments partially activated the AsA-GSH cycle. As a result, direct SA application was effective in mitigating stress-induced physiological limitations with high SA accumulation in the tissues, while encapsulated SA treatment was more effective in regulating photosynthetic and biochemical reactions, alleviating oxidative damage by activating the antioxidant defense, and promoting growth under stress with moderate SA accumulation.

Excised leaves show limited and species-specific effects on photosynthetic parameters across crop functional types.

Photosynthesis is increasingly becoming a recognized target for crop improvement. Phenotyping photosynthesis-related traits on field-grown material is a key bottleneck to progress here due to logistical barriers and short measurement days. Many studies attempt to overcome these challenges by phenotyping excised leaf material in the laboratory. To date there are no demonstrated examples of the representative nature of photosynthesis measurements performed on excised leaves relative to attached leaves in crops. Here, we tested whether standardized leaf excision on the day prior to phenotyping affected a range of common photosynthesis-related traits across crop functional types using tomato (C3 dicot), barley (C3 monocot), and maize (C4 monocot). Potentially constraining aspects of leaf physiology that could be predicted to impair photosynthesis in excised leaves, namely leaf water potential and abscisic acid accumulation, were not different between attached and excised leaves. We also observed non-significant differences in spectral reflectance and chlorophyll fluorescence traits between the treatments across the three species. However, we did observe some significant differences between traits associated with gas exchange and photosynthetic capacity across all three species. This study represents a useful reference for those who perform measurements of this nature and the differences reported should be considered in associated experimental design and statistical analyses.

Settleable atmospheric particulate matter affects the swimming performance and aerobic metabolic rate of Nile tilapia (Oreochromis niloticus)

Atmospheric particulate matter (APM) produced by the steel industry comprises a complex mixture of particles that includes a wide variety of metals and metallic nanoparticles. These particles settle out onto areas surrounding the industries. There is evidence that this ‘settleable’ APM (SePM) may cause air-to-water cross-contamination with significant effects on aquatic biota. Recent investigations have reported sublethal impacts on the gill structure and blood oxygen-carrying capacity of fishes, which raises the hypothesis that there will be consequences for gas exchange capacity and ability to support aerobic activities. Therefore, we investigated the effects of an environmentally relevant level of SePM contamination on swimming performance and associated aerobic metabolic rates in Nile tilapia, Oreochromis niloticus. Short-term exposure (96 h) to SePM reduced critical swimming speed, energetic efficiency of aerobic swimming, standard metabolic rate, maximum metabolic rate, and aerobic scope. The compromised swimming performance could have adverse ecological effects by limiting foraging ability, predator evasion, territorial protection, and migration. The impairments to aerobic capacity could also affect overall fish performance by influencing long-term energy balance and allocation to growth and reproduction. Thus, despite being sublethal, SePM contamination is considerably debilitating, and if its limiting effects are not compensated for in the longer term, this may reduce the survival and fitness of fish populations.

PULM2: Combining Extracorporeal Lung and Kidney Support: Evaluation of Fibre Configurations on Gas Exchange Preservation for the Development of a Novel Highly Integrated Device (RenOx)

Background: Combined lung and kidney dysfunction are frequent in extracorporeal membrane oxygenation (ECMO) patients affecting up to 70% of them. Current treatment relies on the use of two separate circuits combining ECMO and renal replacement therapy, increasing infection risks and the use of artificial surfaces. Therefore, we aim to develop a novel artificial lung that integrates lung and kidney support in a single device combining oxygenation and hemodialysis fibers. Thus, we analyzed how many oxygenation fibers could be substituted by hemodialysis fibers while still maintaining 90% of the oxygenator’s gas exchange capacity and the effect fiber configuration has on oxygen (O2) and carbon dioxide (CO2) transfer. Methods: Fiber bundles were composed of oxygenation fiber mats (Oxyplus™ 90/200, 3M) stacked perpendicularly at a 90° angle and/or crossed at a 24° angle on top of each other. We manufactured bundles with all oxygenation fibers open and bundles with oxygenation fibers closed in a way that they could not contribute to gas exchange, simulating hemodialysis fibers. Bundles in perpendicular configuration had 100% of fibers open (Oxy100P), 50% of fibers closed (Oxy50P), or 25% of fibers closed (Oxy75P), Figure 1. Bundles in crossed configuration had all fibers open (Oxy100C) or 33% of fibers closed (Oxy67C). Bundles were tested for gas exchange performance following in-vitro blood tests according to ISO 7199:2016. Results: Our results show that bundles with 25% of oxygenation fibers closed in perpendicular configuration were able to still maintain 90% of the O2 exchange and 80% of the CO2 exchange capacity of our oxygenator. Bundles with 25% oxygenation fibers closed had no statistically significant difference in O2 or CO2 transfer compared to a fully open oxygenator with the same fiber configuration, Figure 2. Additionally, Oxy75P bundles were able to keep O2 delivery above 55 mL/LBlood flow and CO2 removal above 52 mL/LBlood flow up to 140 mL/min. Fiber configuration did not affect gas exchange for fully open bundles, however, configuration significantly influenced O2 and CO2 exchange for bundles with closed fiber layers. Closing fibers in perpendicular configuration resulted in a lower decrease in gas transfer. Below 140 mL/min, this was demonstrated by a similar decrease in O2 transfer of 20% when 50% of perpendicular fibers or 33% of crossed fibers were closed Conclusions: We analyzed the effect of replacing oxygenation fibers with hemodialysis fibers on gas exchange efficiency. Our results demonstrate that 25% of oxygenation fibers in a perpendicular configuration could be replaced by hemodialysis fibers while still maintaining 90% of the O2 exchange of our oxygenator. Moreover, this type of bundle kept O2 delivery above 55 mL/LBlood flow up to 140 mL/min. This shows that gas exchange can be preserved to a desirable extent when oxygenation fiber layers are replaced. This is a step towards combining lung and kidney support in a single device.Figure 1. Illustration of a device combining extracorporeal lung and kidney support. Oxygen flows through the lumen of oxygenation fibers and dialysate flows inside hemodialysis fibers. In this work, fiber bundles were manufactured with a perpendicular and/or crossed configuration having a varying number of oxygenation fiber layers closed, simulating hemodialysis fibers (open fibers in white and closed fibers in blue). Perpendicular bundles had 50% of fibers closed (Oxy50P), 25% of fibers closed (Oxy75P), or 100% of fibers open (Oxy100P), while crossed bundles had 33% of fibers closed (Oxy67C), or all fibers open (Oxy100C).Figure 2. Oxygen exchange performance mL/LBlood flow ± standard deviation from the mean (n = 10) for bundles with different fiber configurations. We found no statistically significant difference in mean oxygen exchange between Oxy75P and the fully open oxygenator Oxy100P (ANOVA p > 0.38).

Combined Pulmonary Fibrosis and Emphysema: When Scylla and Charybdis Ally.

Combined pulmonary fibrosis and emphysema (CPFE) is a recently recognized syndrome that, as its name indicates, involves the existence of both interstitial lung fibrosis and emphysema in one individual, and is often accompanied by pulmonary hypertension. This debilitating, progressive condition is most often encountered in males with an extensive smoking history, and is presented by dyspnea, preserved lung volumes, and contrastingly impaired gas exchange capacity. The diagnosis of the disease is based on computed tomography imaging, demonstrating the coexistence of emphysema and interstitial fibrosis in the lungs, which might be of various types and extents, in different areas of the lung and several relative positions to each other. CPFE bears high mortality and to date, specific and efficient treatment options do not exist. In this review, we will summarize current knowledge about the clinical attributes and manifestations of CPFE. Moreover, we will focus on pathophysiological and pathohistological lung phenomena and suspected etiological factors of this disease. Finally, since there is a paucity of preclinical research performed for this particular lung pathology, we will review existing animal studies and provide suggestions for the development of additional in vivo models of CPFE syndrome.

Effects of Exogenous ALA on Leaf Photosynthesis, Photosynthate Transport, and Sugar Accumulation in Prunus persica L.

Peaches/nectarines (Prunus persica L.) are widely cultivated worldwide. As with other species, the sugar content is the most important trait for fruit quality, especially for precocious cultivars. Most fruits need to improve their sugar content in order to be more profitable under fierce market competition. 5-Aminolevulinic acid (ALA), a naturally occurring δ-amino acid, has been shown to improve leaf photosynthesis and fruit quality, especially sugar content. However, the mechanisms are not clear. The objective of this study is to determine the effects of exogenous ALA on leaf photosynthesis, assimilate transport, and sugar accumulation during fruit development. We used the field-cultivated precocious nectarine ‘Zhongyoutao 4’ and potted cultivated peach ‘Zhongai 33’ as materials, whereas in the second experiment, we used 14C radiolabeling to trace 14C fixation in leaves, transport in branches, and distribution in different organs. The results showed that ALA significantly enhanced the photosynthetic gas exchange capacity, and the effects were maintained for at least one month. The results of the 14C radiolabel experiment showed that ALA enhanced 14C fixation in leaves, promoted the transport to fruits, and reduced the allocation rate of young leaves. This suggests that ALA enlarges “source” volume and strengthens “sink” competition; therefore, assimilate translocation to fruits is promoted. It was observed that sucrose contributed the main saccharide for peach fruit quality at maturity, which might not be converted from glucose or fructose but from starch degradation. ALA improved starch accumulation in the young fruits as well as degradation during maturity. The RT-qPCR showed that the expression of most genes involved in sugar metabolism did not correlate or even negatively correlate with fruit sucrose content. However, the expressions of SWEET1/6/7/8/15/16/17 were highly correlated with the sucrose content, and exogenous ALA treatment up-regulated the gene expression at fruit maturity, suggesting they might play an important role in fruit sugar accumulation. These results provide important theoretical support for ALA application in fruit quality improvement, as well as a regulatory mechanism study on sugar accumulation in fruits.

Cultivating the Mediterranean Wild Edible Species Cichorium spinosum L. in Aquaponics: Functional and Growth Responses to Minimal Nutrient Supplementation

Aquaponics is a plant and fish co-cultivation system with high sustainability, yet sub-optimal concentrations of Fe and K often compromise crop yields. We cultivated the Mediterranean wild edible Cichorium spinosum L. (Greek name: stamnagathi) in an aquaponics setup following a minimal supplementation approach that focused on Fe and K. Stamnagathi and tilapia fish were co-cultivated under (i) solely Fe, (ii) Fe+K input and (iii) no-input Control treatments. We aimed to evaluate the feasibility of aquaponics for stamnagathi cultivation, identify the system’s bottlenecks, and propose optimization measures. Several plant’s growth and functional parameters were monitored throughout the 35-day experimental period, notably instantaneous gas exchange and photosynthetic capacity via light response curves, state and efficiency of the photosynthetic machinery, pigment content, and yield and morphometric assessments. Fish growth characteristics and survival rates remained unaffected. Fe deficiency was crucial in shaping the responses of Control stamnagathi, which showed inferior performance in terms of photochemistry, chlorophylls content, light use efficiency and, subsequently, photosynthetic activity. Fe and Fe+K-treated plants exhibited similarly high performance in all studied parameters and achieved 4.5- and 4-fold increased yields, respectively, compared to Control. The results demonstrate that aquaponics is an advantageous cropping system for stamnagathi and solely Fe supplementation is adequate to promote excellent performance and yield of this oligotrophic species.

Anatomical responses of leaf and stem of Catalpa bungei C.A.Mey. to nitrogen application and Rhizophagus intraradices inoculation

Plant morphology and anatomical structure are closely related to plant function, and their changes may affect physiological processes and may also be altered by nutrient availability or arbuscular mycorrhizal fungi (AMF) inoculation. To our knowledge, studies on the effect of AMF on plant anatomical characteristics under different nitrogen (N) levels are very scarce, especially in trees. Here, a pot experiment was carried out to evaluate the response of leaf and stem anatomy of Catalpa bungei using a two-factor completely randomized block design, including mycorrhizal inoculation (inoculation with Rhizophagus intraradices or not) and N application (low, medium, high). Regardless of the inoculation status, moderate N addition promoted leaf and stem development, while excessive N had a significant negative impact on the anatomical structure of seedlings. Compared with the non-inoculated treatments, AMF inoculation increased most of the leaf stomatal characteristic parameters and stem structural parameters of C. bungei seedlings, while significantly reduced leaf upper epidermis thickness (UET), lower epidermis thickness (LET), spongy tissue thickness (STT), and leaf thickness (LT) at low to medium N levels. In addition, the lenticel density (LD) at low N levels and the lenticel length (LL), width (LW), and area (SLA) at medium N levels in mycorrhizal seedlings were significantly higher than those in non-mycorrhizal seedlings. We concluded that AMF inoculation may significantly improve the water and gas exchange capacity of seedlings at least at low to medium N levels.

Intratracheally injected human-induced pluripotent stem cell-derived pneumocytes and endothelial cells engraft in the distal lung and ameliorate emphysema in a rat model

ObjectivesPulmonary emphysema is characterized by the destruction of alveolar units and reduced gas exchange capacity. In the present study, we aimed to deliver induced pluripotent stem cell-derived endothelial cells and pneumocytes to repair and regenerate distal lung tissue in an elastase-induced emphysema model. MethodsWe induced emphysema in athymic rats via intratracheal injection of elastase as previously reported. At 21 and 35 days after elastase treatment, we suspended 80 million induced pluripotent stem cell-derived endothelial cells and 20 million induced pluripotent stem cell-derived pneumocytes in hydrogel and injected the mixture intratracheally. On day 49 after elastase treatment, we performed imaging, functional analysis, and collected lungs for histology. ResultsUsing immunofluorescence detection of human-specific human leukocyte antigen 1, human-specific CD31, and anti--green fluorescent protein for the reporter labeled pneumocytes, we found that transplanted cells engrafted in 14.69% ± 0.95% of the host alveoli and fully integrated to form vascularized alveoli together with host cells. Transmission electron microscopy confirmed the incorporation of the transplanted human cells and the formation of a blood–air barrier. Human endothelial cells formed perfused vasculature. Computed tomography scans revealed improved vascular density and decelerated emphysema progression in cell-treated lungs. Proliferation of both human and rat cell was higher in cell-treated versus nontreated controls. Cell treatment reduced alveolar enlargement, improved dynamic compliance and residual volume, and improved diffusion capacity. ConclusionsOur findings suggest that human induced pluripotent stem cell-derived distal lung cells can engraft in emphysematous lungs and participate in the formation of functional distal lung units to ameliorate the progression of emphysema.