Simultaneous removal of NOx and SO2 from simulated marine ship flue gas in a novel wet scrubbing system based on divided diaphragm seawater electrolysis technology: efficiency optimization and economic assessment.

This work constructed a divided diaphragm seawater electrolysis system with two tandem packed towers for the synergistic removal of NOx and SO2. The first tower was mainly used to oxidize NO and SO2 by AC (active chlorine), and the second tower was used to further absorb NOx. The factors affecting on NO removal, including ACC (active chlorine concentration), pH value, initial NO concentration and temperature in the oxidation tower were investigated. Moreover, the effect of different inlet gas concentrations and current values were explored. The results showed that with the increase of ACC, the NO and NOx removal efficiency increased rapidly, but when the ACC was higher than 500 mg/L [Cl2], the removal efficiency did not increase further in the oxidation tower. Low pH values in the oxidation tower were favorable for NO removal. NO removal efficiency reached a maximum at 40 °C. Higher NO and SO2 concentrations were favorable for NO removal. The decline of pH in the anode cell was not conducive to the storage of AC in the continuous electrolysis removal process. NOx and SO2 were almost completely removed after being scrubbed in the oxidation and absorption towers. The relationship between current and removal efficiency of NO and SO2 in the oxidation tower was also analyzed. Finally, the removal mechanism and the application prospects were discussed.

Noninvasive ultrasound imaging for assessment of intact microstructure of extracellular matrix in tissue engineering.

Development of artificial tissues or organs is one of the actual tasks in regenerative medicine that requires observation and evaluation of intact volume microstructure of tissue engineering products at all stages of their formation, from native donor tissues and decellularized scaffolds to recipient cell migration in the matrix. Unfortunately in practice, methods of vital noninvasive imaging of volume microstructure in matrixes are absent. In this work, we propose a new approach based on high-frequency acoustic microscopy for noninvasive evaluation and visualization of volume microstructure in tissue engineering products. The results present the ultrasound characterization of native rat diaphragms and lungs and their decellularized scaffolds. Verification of the method for visualization of tissue formation in the matrix volume was described in the model samples of diaphragm scaffolds with stepwise collagenization. Results demonstrate acoustic microscopic sensitivity to cell content concentration, variation in local density, and orientation of protein fibers in the volume, micron air inclusions, and other inhomogeneities of matrixes.

Estimation of Decellularization and Recellularization Quality of Tissue-Engineered Constructions by the Chemiluminescence Method.

It was found that the chemiluminescence intensity in native and recellularized tissues of rat muscular organs as well as in their decellularized scaffolds can serve as an express criterion that, along with ultrastructural analysis, makes it possible to perform quantitative assessment of the viability of cellular structures in biological samples of the diaphragm.

Decellularized Diaphragmatic Muscle Drives a Constructive Angiogenic Response In Vivo.

Skeletal muscle tissue engineering (TE) aims to efficiently repair large congenital and acquired defects. Biological acellular scaffolds are considered a good tool for TE, as decellularization allows structural preservation of tissue extracellular matrix (ECM) and conservation of its unique cytokine reservoir and the ability to support angiogenesis, cell viability, and proliferation. This represents a major advantage compared to synthetic scaffolds, which can acquire these features only after modification and show limited biocompatibility. In this work, we describe the ability of a skeletal muscle acellular scaffold to promote vascularization both ex vivo and in vivo. Specifically, chicken chorioallantoic membrane assay and protein array confirmed the presence of pro-angiogenic molecules in the decellularized tissue such as HGF, VEGF, and SDF-1α. The acellular muscle was implanted in BL6/J mice both subcutaneously and ortotopically. In the first condition, the ECM-derived scaffold appeared vascularized 7 days post-implantation. When the decellularized diaphragm was ortotopically applied, newly formed blood vessels containing CD31⁺, αSMA⁺, and vWF⁺ cells were visible inside the scaffold. Systemic injection of Evans Blue proved function and perfusion of the new vessels, underlying a tissue-regenerative activation. On the contrary, the implantation of a synthetic matrix made of polytetrafluoroethylene used as control was only surrounded by vWF⁺ cells, with no cell migration inside the scaffold and clear foreign body reaction (giant cells were visible). The molecular profile and the analysis of macrophages confirmed the tendency of the synthetic scaffold to enhance inflammation instead of regeneration. In conclusion, we identified the angiogenic potential of a skeletal muscle-derived acellular scaffold and the pro-regenerative environment activated in vivo, showing clear evidence that the decellularized diaphragm is a suitable candidate for skeletal muscle tissue engineering and regeneration.

EPR spectroscopy solutions for assessment of decellularization of intrathoracic organs and tissues.

Using EPR spectroscopy it was established that the determination of the concentration of paramagnetic centers in lyophilized tissues allows indirect evaluation of the quality of decellularization of intrathoracic organs (diaphragm, heart, and lungs), since the content of paramagnetic particles in them can serve as a criterion of cell viability and points to the necessity to repeat decellularization. Experiments in rats showed that the EPR spectra of the native thoracic organs contained paramagnetic centers with g-factor values ranging from 2.007 to 2.011 at a concentration of 10(-8) to 6.62 × 10(-7) mol/g of lyophilized tissue, whereas in all decellularized tissues of the same organs paramagnetic particles were not detected.

IgG anti-Galnac-GD1a antibodies bind to neuromuscular junctions of rat hemidiaphragm.

INTRODUCTION: We investigated the localization of a ganglioside, N-acetylgalactosaminyl GD1a (GalNAc-GD1a), in peripheral nerves with an IgG anti-GalNAc-GD1a antibody, which was produced in rabbits immunized with GalNAc-GD1a. METHODS: Teased fibers from ventral and dorsal roots and hemidiaphragm sections of rats were assessed using fluorescent double- and triple-labeling methods. RESULTS: The nodal and paranodal regions of teased fibers from ventral roots were immunostained with IgG anti-GalNAc-GD1a antibodies. After collagenase treatment, no staining was seen with IgG anti-GalNAc-GD1a or anti-NF200 antibodies, whereas α-bungarotoxin selectively stained nerve terminals. In cross-sectional and longitudinal sections of rat hemidiaphragm, IgG anti-GalNAc-GD1a antibodies overlapped with α-BuTx and anti-NF200 antibodies, indicating that GalNAc-GD1a is localized to the nerve terminal. IgG anti-GalNAc-GD1a antibody staining also overlapped with that of AChR clusters and syntaxin-positive presynaptic nerve terminals. CONCLUSION: GalNAc-GD1 is localized in both pre- and postsynaptic nerve terminals of neuromuscular junctions.

Rapidly progressive diaphragmatic weakness and injury during mechanical ventilation in humans.

RATIONALE: Diaphragmatic function is a major determinant of the ability to successfully wean patients from mechanical ventilation (MV). Paradoxically, MV itself results in a rapid loss of diaphragmatic strength in animals. However, very little is known about the time course or mechanistic basis for such a phenomenon in humans. OBJECTIVES: To determine in a prospective fashion the time course for development of diaphragmatic weakness during MV; and the relationship between MV duration and diaphragmatic injury or atrophy, and the status of candidate cellular pathways implicated in these phenomena. METHODS: Airway occlusion pressure (TwPtr) generated by the diaphragm during phrenic nerve stimulation was measured in short-term (0.5 h; n = 6) and long-term (>5 d; n = 6) MV groups. Diaphragmatic biopsies obtained during thoracic surgery (MV for 2-3 h; n = 10) and from brain-dead organ donors (MV for 24-249 h; n = 15) were analyzed for ultrastructural injury, atrophy, and expression of proteolysis-related proteins (ubiquitin, nuclear factor-κB, and calpains). MEASUREMENTS AND MAIN RESULTS: TwPtr decreased progressively during MV, with a mean reduction of 32 ± 6% after 6 days. Longer periods of MV were associated with significantly greater ultrastructural fiber injury (26.2 ± 4.8 vs. 4.7 ± 0.6% area), decreased cross-sectional area of muscle fibers (1,904 ± 220 vs. 3,100 ± 329 µm²), an increase of ubiquitinated proteins (+19%), higher expression of p65 nuclear factor-κB (+77%), and greater levels of the calcium-activated proteases calpain-1, -2, and -3 (+104%, +432%, and +266%, respectively) in the diaphragm. CONCLUSIONS: Diaphragmatic weakness, injury, and atrophy occur rapidly in critically ill patients during MV, and are significantly correlated with the duration of ventilator support.

[Changes of rat respiratory and locomotory muscles during aerobic exercise training in continuous and interval regimens].

Male Wistar rats were treadmill-trained for 8 weeks using one of the two regimens: with the constant running speed or with alternating high-speed and low-speed intervals. Both training regimens led to an increase of rat aerobic capacities and to a higher citrate synthase activity in the medial head of gastrocnemius muscle. No differences between the effects of two training regimens were observed. However, in contrast to constant-speed training the interval one resulted in myocardium hypertrophy and also in less pronounced changes in diaphragm muscle, such as slow-direction shift of myosin phenotype and reduction of muscle fiber cross-sectional area. Neither of the training regimens had an effect on corticosterone and thyroid hormones levels in rat blood, whereas the interval training resulted in a higher level of testosterone. Anabolic influence of testosterone during interval aerobic training may be favorable for heart hemodynamic capacity and force characteristics of the diaphragm.

Hypoglycemic and antioxidative activity evaluation of phenolic compounds derived from walnut diaphragm produced in Xinjiang.

Walnut diaphragm is defined as a dry wood septum located between the walnut shell and kernel. In this work, seven phenolic compounds from walnut diaphragm were purified and characterized, and their antioxidant activities and mechanisms of hypoglycemia were investigated. Compounds 1-7 were tested for DPPH, ABTS scavenging ability, and FRAP assay to evaluate the antioxidant activity. α-Amylase inhibition assay was introduced to assess the hypoglycemic activity, and the mechanism was investigated by kinetic analysis, CD spectrum, and molecular docking. Compound 6 showed the strongest antioxidant ability, while compound 1 exhibited the strongest inhibition of α-amylase by changing the secondary structure of α-amylase in a mixed competitive inhibition mode. Molecular docking test predicted that the tetrahydropyran part in compound 1 may contribute to its hypoglycemic effect. This study furnishes a new theoretical reference for the utilization and development of walnut diaphragm into a health food with antioxidant and hypoglycemic properties. PRACTICAL APPLICATIONS: The finding of this research may serve as a basis for the subsequent development of walnut diaphragm into instant tea-based health food or added to other food carriers to achieve auxiliary antioxidant and hypoglycemic effects. This study revealed that polyphenolic components were the material basis for the antioxidant and hypoglycemic effects of walnut diaphragm, which could be identified as landmark chemical components for controlling quality standards in the development of walnut diaphragm, thus accelerating the research process of quality standards for walnut diaphragm-related products. Furthermore, the studies on the mechanism of hypoglycemic activity supply more credible data to support the development of walnut diaphragm into a safe and consumer-friendly health food. With abundant resources and clear efficacy, walnut diaphragm has great development prospect and application value.

N-Acetylcysteine protects the rat diaphragm from the decreased contractility associated with controlled mechanical ventilation.

OBJECTIVE: Controlled mechanical ventilation results in diaphragmatic dysfunction, and oxidative stress has been shown to be an important contributor to ventilator-induced diaphragm dysfunction. We hypothesized that the administration of an antioxidant, N-acetylcysteine, would restore the redox balance in the diaphragm and prevent against the deleterious effects of controlled mechanical ventilation. DESIGN: Randomized, controlled experiment. SETTINGS: Basic science animal laboratory. SUBJECTS: Male Wistar rats, 14 wks old. INTERVENTIONS: Anesthetized rats were submitted for 24 hrs to either spontaneous breathing receiving 150 mg/kg N-acetylcysteine (SBNAC) or saline (SBSAL) or to controlled mechanical ventilation receiving 150 mg/kg N-acetylcysteine (MVNAC) or saline (MVSAL). MEASUREMENTS AND MAIN RESULTS: After 24 hrs of controlled mechanical ventilation, diaphragmatic force production was significantly lower in MVSAL compared with all groups. Importantly, administration of N-acetylcysteine completely abolished this controlled mechanical ventilation-induced diaphragmatic contractile dysfunction. Diaphragmatic protein oxidation was significantly increased after 24 hrs of controlled mechanical ventilation (+53%, p < .01) in MVSAL animals, whereas administration of N-acetylcysteine prevented this controlled mechanical ventilation-induced oxidative stress. Diaphragmatic 20S proteasome activity was increased in MVSAL (+62%, p < .05). Further, compared with SBSAL, diaphragm caspase-3 activity was significantly increased in MVSAL (+279%, p < .001), and N-acetylcysteine treatment provided partial protection against caspase-3 activation. Diaphragmatic calpain activity was significantly increased after controlled mechanical ventilation (+137%, p < .001) in MVSAL animals, but N-acetylcysteine treatment protected against this event. Finally, significant negative correlations existed between calpain activity and diaphragm force production (r from -0.56 to -0.49, p < .05). CONCLUSIONS: These data show that the administration of N-acetylcysteine protects the diaphragm from the deleterious effects of controlled mechanical ventilation. Specifically, N-acetylcysteine prevents against controlled mechanical ventilation-induced diaphragmatic oxidative stress and proteolysis and abolishes controlled mechanical ventilation-induced diaphragmatic contractile dysfunction.

Transgenic mdx mice expressing dystrophin with a deletion in the actin-binding domain display a "mild Becker" phenotype.

The functional significance of the actin-binding domain of dystrophin, the protein lacking in patients with Duchenne muscular dystrophy, has remained elusive. Patients with deletions of this domain (domain I) typically express low levels of the truncated protein. Whether the moderate to severe phenotypes associated with such deletions result from loss of an essential function, or from reduced levels of a functional protein, is unclear. To address this question, we have generated transgenic mice that express wild-type levels of a dystrophin deleted for the majority of the actin-binding domain. The transgene derived protein lacks amino acids 45-273, removing 2 of 3 in vitro identified actin interacting sites and part of hinge 1. Examination of the effect of this deletion in mice lacking wild-type dystrophin (mdx) suggests that a functional domain I is not essential for prevention of a dystrophic phenotype. However, in contrast to deletions in the central rod domain and to full-length dystrophin, both of which are functional at only 20% of wild-type levels, proteins with a deletion in domain I must be expressed at high levels to prevent a severe dystrophy. These results are also in contrast to the severe dystrophy resulting from truncation of the COOH-terminal domain that links dystrophin to the extracellular matrix. The mild phenotype observed in mice with domain I-deletions indicates that an intact actin-binding domain is not essential, although it does contribute to an important function of dystrophin. These studies also suggest the link between dystrophin and the subsarcolemmal cytoskeleton involves more than a simple attachment of domain I to actin filaments.

Proteomic profiling of x-linked muscular dystrophy.

Progressive x-linked muscular dystrophy represents the most commonly inherited neuromuscular disorder in humans. Although the disintegration of the dystrophin-associated glycoprotein complex triggers the initial pathogenesis of Duchenne muscular dystrophy, secondary alterations in metabolic pathways, cellular signaling and the regulation of ion homeostasis are probably crucial factors that cause end-stage fibre degeneration. The application of mass spectrometry-based proteomics for the global cataloguing of muscle biomarkers has recently been applied to the analysis of the mdx animal model of muscular dystrophy and the biochemical evaluation of experimental exon skipping therapy. The fluorescence difference in-gel electrophoretic analysis of normal versus mdx diaphragm muscle revealed changed expression levels of proteins involved in nucleotide metabolism, Ca 2+-handling, the cellular stress response and key bioenergetic processes. The swift up-regulation of small heat shock proteins, such as cvHsp, seems to form an integral part of the repair mechanisms in dystrophic fibres and may be exploitable as a new option to treat inherited muscle degeneration. Importantly, the mass spectrometry-based profiling of mdx muscle following the specific removal of exon 23 in the mutated dystrophin gene transcript showed a partial reversal of important secondary changes. Experimental exon skipping restored the expression of the dystrophin isoform Dp427, its associated glycoprotein beta-dystroglycan, neuronal nitric oxide synthase, calsequestrin, adenylate kinase and the muscle-specific stress protein cvHsp. In the future, a well defined set of signature molecules could be used to improve diagnosis, monitor disease progression, identify new therapeutic pathways, and validate the effects of novel drugs or experimental treatments such as gene therapy.

DNA topoisomerase IIbeta and neural development.

DNA topoisomerase IIbeta is shown to have an unsuspected and critical role in neural development. Neurogenesis was normal in IIbeta mutant mice, but motor axons failed to contact skeletal muscles, and sensory axons failed to enter the spinal cord. Despite an absence of innervation, clusters of acetylcholine receptors were concentrated in the central region of skeletal muscles, thereby revealing patterning mechanisms that are autonomous to skeletal muscle. The defects in motor axon growth in IIbeta mutant mice resulted in a breathing impairment and death of the pups shortly after birth.

Identification and Quantification of Bioactive Compounds in Diaphragma juglandis Fructus by UHPLC-Q-Orbitrap HRMS and UHPLC-MS/MS.

Diaphragma juglandis fructus is the dry wooden diaphragm inside walnuts and a byproduct in food processing of walnut kernels. The purpose of our research is to enrich the information on compounds in Diaphragma juglandis fructus to further discover and exploit its potential nutritional value. In this study, new quali-quantitative analytical approaches were developed to identify and determine bioactive compounds in Diaphragma juglandis fructus. Two-hundred compounds, including hydrolyzable tannins, flavonoids, phenolic acids, and quinones, were identified by UHPLC-Q-Orbitrap HRMS, more than 150 of which were first discovered in Diaphragma juglandis fructus. Among them, 21 major dietary polyphenols with health-promoting effects were successfully quantified using UHPLC-MS/MS, with total contents of 2.88-6.18 mg/g. This successful characterization and quantification of bioactive compounds in Diaphragma juglandis fructus gives a better understanding of its potential nutritional value and supports efficiently developing and reusing it instead of discarding it as agrofood waste.

Mitochondrial accumulation of doxorubicin in cardiac and diaphragm muscle following exercise preconditioning.

Doxorubicin (DOX) is a highly effective anthracycline antibiotic. Unfortunately, the clinical use of DOX is limited by the risk of deleterious effects to cardiac and respiratory (i.e. diaphragm) muscle, resulting from mitochondrial reactive oxygen species (ROS) production. In this regard, exercise is demonstrated to protect against DOX-induced myotoxicity and prevent mitochondrial dysfunction. However, the protective mechanisms are currently unclear. We hypothesized that exercise may induce protection by increasing the expression of mitochondria-specific ATP-binding cassette (ABC) transporters and reducing mitochondrial DOX accumulation. Our results confirm this finding and demonstrate that two weeks of exercise preconditioning is sufficient to prevent cardiorespiratory dysfunction.

Antithrombin activity and disaccharide composition of dermatan sulfate from different bovine tissues.

Dermatan sulfate is a glycosaminoglycan that selectively inhibits the action of thrombin through interaction with heparin cofactor II. Unlike heparin it does not interact with other coagulation factors and is able to inhibit thrombin associated with clots. This property has made dermatan sulfate an attractive candidate as an antithrombotic drug. Previous studies have showed that dermatan sulfate derived from porcine/bovine intestinal mucosa/skin or marine invertebrates is capable of stimulating heparin cofactor II-mediated thrombin inhibition in vitro. This biological activity is reported for the first time in this study using dermatan sulfate derived from mammalian tissues other than intestinal mucosa or skin. Ten different bovine tissues including the aorta, diaphragm, eyes, large and small intestine, esophagus, skin, tendon, tongue, and tongue skin were used to prepare dermatan sulfate-enriched fractions by anion exchange chromatography and acetone precipitation. Heparin cofactor II/dermatan sulfate-mediated thrombin inhibition measured in vitro revealed activity comparable to or higher than the commercial standard with 2-fold differences observed between some tissues. Analysis of the extracted dermatan sulfate using fluorophore-assisted carbohydrate electrophoresis revealed significant differences in the relative percentage of all the mono-sulfated disaccharides, in particular the predominant mammalian disaccharide uronic acid-->N-acetyl-D-galactosamine-4-O-sulfate, confirming previous reports regarding variations in sulfation in dermatan sulfate from different tissues. Overall, these findings demonstrate that dermatan sulfate extracted from a range of bovine tissues exhibits in vitro antithrombin activity equivalent to or higher than that observed for porcine intestinal mucosa, identifying additional sources of dermatan sulfate as potential antithrombotic agents.

C-reactive protein measurements in meat juice of pigs.

A time-resolved immunofluorometric assay was evaluated for measurement of C-reactive protein in meat juice from diaphragmatic muscle collected from slaughtered pigs. Analytical and clinical validation of the method was performed by using meat juice samples, obtained by freezing and thawing muscle pieces. The intra- and inter-assay coefficients of variation ranged from 2.2-5.8% to 7.9-14.3%, respectively. The limit of detection was 0.00038 microg/ml. The method measured the CRP concentrations in a linear manner with a good accuracy (r=0.99). CRP concentrations in serum were highly correlated with those in diaphragmatic meat juice (r=0.90; p<0.001). CRP concentrations were significantly higher in clinically affected pigs compared to non-diseased pigs. The assay described here provides a sensitive method for measuring CRP concentrations in meat juice, which can represent a suitable alternative to serum or blood samples and simplifies the process of sampling collection at slaughter.

Apoptotic-related protein expression in the diaphragm and the effect of dopamine during inspiratory resistance loading.

Dopamine (DA) is a free radical scavenger that attenuates apoptosis. We studied the effects of normal saline (NS) and DA on diaphragm apoptotic protein expression following 60 min of inspiratory resistance loading in rats. We tested for 27 apoptotic-related proteins and found 12 in the diaphragm. Of the 12 proteins, superoxide dismutase copper zinc (SOD [CuZn]) and proprioceptive event related potential (PERP) were significantly higher in the DA group than in the NS and sham groups (p = .002, p = .007). DA group diaphragms had significantly greater expression of SOD (CuZn) than the NS (p = .005) and sham group diaphragms (p = .003). Likewise, the DA group had significantly greater expression of PERP than the NS group (p = .008). These results suggest that DA decreases diaphragm apoptosis through elevated expression of SOD (CuZn). The identification of 12 apoptotic-related proteins will assist investigators as they study diaphragm apoptosis.

Palynological Investigation of Mummified Human Remains.

Pollen analysis was applied to a mummified homicide victim in Nebraska, U.S.A., to determine the location of death. A control sample showed the normal ambient pollen in the garage crime scene. Ambient windborne types, common in the air of the region, dominated the control. Internal samples were analyzed from the sacrum, intestine, and diaphragm. Microfossils were recovered from the rehydrated intestine lumen. The intestinal sample was dominated by Brassica (broccoli). The sacrum sample was high in dietary types but with a showing of ambient types. The pollen from the diaphragm was dominated by ambient pollen similar to the control samples. The discovery of diverse pollen spectra from within a single mummy was unexpected. They show that ingested and inhaled pollen mixed in the corpse. The data linked the decedent to a specific crime scene in her Nebraska home in the southern tier of eastern counties on the border with Kansas.

How to Wire the Diaphragm: Wholemount Staining Methods to Analyze Mammalian Respiratory Innervation.

Direct or indirect impairment of breathing in humans by diseases or environmental factors can either cause long-term disability and pain, or can ultimately result in death. Automatic respiratory centers in the brainstem control the highly structured process of breathing and signal to a specialized group of motor neurons in the cervical spinal cord that constitute the phrenic nerves. In mammals, the thoracic diaphragm separates the thorax from the abdomen and adopts the function of the primary respiratory musculature. Faithful innervation by the phrenic nerves is a prerequisite for correct functionality of this highly specialized musculature and thus, ultimately, the viability of the entire organism.To analyze the effects of diseases and genetic defects responsible for deleterious or lethal respiratory phenotypes, accurate imaging of respiratory innervation during embryonic development, e.g., in genetically modified mouse models enables the characterization of specific marker genes and pathways that underlie appropriate wiring of the diaphragm. Among the different available immunostaining techniques, wholemount staining methods provide the advantage of clear and faithful three-dimensional information about the location of the antigens of interest. In comparison to routine histological techniques, however, the researcher has to deal with technical challenges, such as antibody penetration, the stability and availability of the antigen, and clearing of the relevant tissue, and the need to be equipped with state-of-the-art microscope equipment.In this methodological chapter, we explain and share our expertise concerning wholemount processing of mouse embryos and thoracic diaphragms for the analysis of mammalian respiratory innervation.