Influence of Salt Bridge Formation on Helix Stability

One of the most common structural elements in proteins is the a-helix. The main goal of this study was to see If the helical properties of short peptide chains could be increased by the formation of salt bridges between side chains. It has been shown that i,i+4 peptides posses helic; I characier. The research that has been done was to make a hybrid peptide chain, that had partial i,i+4 and partial i,i+3 salt bridge formation. The hybrid peptide was a i+4, i+3, i+4 peptide chain. The overall purpose of making this type of hybrid peptide was to make the approximate number of residues in a tum of the helix closer to the 3.6 residues, which is the number of residues in a natural tum of the helix. The charged amino acids used were positive lysine residues and negative glutamate residues. The peptides were constructed through solid-phase synthesis and purified using HPLC. The stability of the peptides were examined theoretically using molecular modeling and experimentally the helicity was tested by Circular Dichroism. The experimental results of the mixed spaced peptides were compared to Stellwagon\u27s and Baldwin\u27s uniformly spaced peptides. This study found that the mixed spaced peptides were at least as stable as the uniformly spaced peptides. A version of the uniformly spaced peptide was also synthesized, but assumed a b-sheet configuration, which is currently under investigation through both experimental and theoretical studies

A nonlinear relationship between marsh size and sediment trapping capacity compromises salt marshes’ stability

Global assessments predict the impact of sea-level rise on salt marshes with present-day levels of sediment supply from rivers and the coastal ocean. However, these assessments do not consider that variations in marsh extent and the related reconfiguration of intertidal area affect local sediment dynamics, ultimately controlling the fate of the marshes themselves. We conducted a meta-analysis of six bays along the United States East Coast to show that a reduction in the current salt marsh area decreases the sediment availability in estuarine systems through changes in regional-scale hydrodynamics. This positive feedback between marsh disappearance and the ability of coastal bays to retain sediments reduces the trapping capacity of the whole tidal system and jeopardizes the survival of the remaining marshes. We show that on marsh platforms, the sediment deposition per unit area decreases exponentially with marsh loss. Marsh erosion enlarges tidal prism values and enhances the tendency toward ebb dominance, thus decreasing the overall sediment availability of the system. Our findings highlight that marsh deterioration reduces the sediment stock in back-barrier basins and therefore compromises the resilience of salt marshes.</jats:p

Divergence of Sediment Fluxes Triggered by Sea-Level Rise Will Reshape Coastal Bays

Sediment budget and sediment availability are direct metrics for evaluating the resilience of coastal bays to sea‐level rise (SLR). Here we use a high‐resolution numerical model of a tidally dominated marsh‐lagoon system to explore feedbacks between SLR and sediment dynamics. SLR augments tidal prism and inundation depth, facilitating sediment deposition on the marsh platform. At the same time, our results indicate that SLR enhances ebb‐dominated currents and increases sediment resuspension, reducing the sediment‐trapping capacity of tidal flats and bays and leading to a negative sediment budget for the entire system. This bimodal distribution of sediments budget trajectories will have a profound impact on the morphology of coastal bays, increasing the difference in elevation between salt marshes and tidal flats and potentially affecting intertidal ecosystems. Our results also clearly indicate that landforms lower with respect to the tidal frame are more affected by SLR than salt marshes

Age as a risk factor in the occurrence of pneumothorax after transthoracic fine needle biopsy: Our experience

AbstractTransthoracic needle biopsy (TTNB) of the lung is a well-established technique for diagnosing many thoracic lesions, and is an important alternative to more invasive surgical procedures. Complications of TTNB include pneumothorax, hemoptysis, hemothorax, infection, and air embolism, with the most common complication as pneumothorax. From June 2011 to June 2014 we performed a prospective study of 188 patients who underwent TTNB with CT guidance at University Hospital of Salerno, Italy. Pneumothorax occurred in 14 of 188 biopsies (7.45%). With the respect of age of patients pneumothorax occurred more frequently in patients aged 60–70 years, while it was less frequent in younger (<60 years) and older patients (>70 years). In conclusion, data of our prospective study documented that CT-guided TTNB is a safe and reliable procedure in elderly patients with suspected chest malignancy and is well tolerated

Dataset of numerical modelling results of wave thrust on salt marsh boundaries with different seagrass coverages in a shallow back-barrier estuary.

This article contains data on the effects of seagrass decline on wave energy along the shoreline of Barnegat Bay (USA) previously evaluated in Donatelli et al., 2019. This study was carried out applying the Coupled-Ocean-Atmosphere-Wave-Sediment Transport (COAWST) numerical modelling framework to six historical maps of seagrass distribution. A new routine recently implemented in COAWST was used, which explicitly computes the wave thrust acting on salt marsh boundaries. The numerical modelling results are reported in terms of wind-wave heights for different seagrass coverages, wind speeds and directions. From a comparison with a numerical experiment without submerged aquatic vegetation, we show how the computed wave thrust on marsh boundaries can be reduced by seagrass beds

Correction: Human Cardiac Progenitor Spheroids Exhibit Enhanced Engraftment Potential

[This corrects the article DOI: 10.1371/journal.pone.0137999.]

Sleep Complaints, Sleep and Breathing Disorders in Myotonic Dystrophy Type 2

PURPOSE OF REVIEW: To update the current knowledge concerning sleep complaints and breathing disorders in myotonic dystrophy type 2 (DM2) and to better understand if sleep and breathing symptoms may add a further clinical definition of DM2. RECENT FINDINGS: Although DM2 has been poorly evaluated, the most relevant sleep disorders are sleep-disordered breathing (SDB) (37.5-66.7%) and restless legs syndrome (RLS) (50-60%). Excessive daytime somnolence (EDS) is not consistent with SDB, and a large percentage of patients with sleep complaints (58-69%) report pain. In addition, respiratory dysfunctions are reported in 6 to 15% of DM2 patients, albeit few data are available regarding pulmonary restriction, hypoventilation, and non-invasive ventilation (NIV). SDB, RLS, and pain may contribute to sleep fragmentation and EDS in DM2. In addition, few studies report hypoventilation and pulmonary restriction, although there are no studies at all on NIV, except for limited clinical experiences. These findings suggest performing a careful pulmonary examination and NIV when required. Furthermore, sleep studies and respiratory evaluation should be recommended if OSA or respiratory muscle dysfunctions are suspected. A large polysomnographic study should be performed to clarify the link between sleep disorders, pain, and sleep disruption in DM2

Human Cardiac Progenitor Spheroids Exhibit Enhanced Engraftment Potential

A major obstacle to an effective myocardium stem cell therapy has always been the delivery and survival of implanted stem cells in the heart. Better engraftment can be achieved if cells are administered as cell aggregates, which maintain their extra-cellular matrix (ECM). We have generated spheroid aggregates in less than 24 h by seeding human cardiac progenitor cells (hCPCs) onto methylcellulose hydrogel-coated microwells. Cells within spheroids maintained the expression of stemness/mesenchymal and ECM markers, growth factors and their cognate receptors, cardiac commitment factors, and metalloproteases, as detected by immunofluorescence, q-RT-PCR and immunoarray, and expressed a higher, but regulated, telomerase activity. Compared to cells in monolayers, 3D spheroids secreted also bFGF and showed MMP2 activity. When spheroids were seeded on culture plates, the cells quickly migrated, displaying an increased wound healing ability with or without pharmacological modulation, and reached confluence at a higher rate than cells from conventional monolayers. When spheroids were injected in the heart wall of healthy mice, some cells migrated from the spheroids, engrafted, and remained detectable for at least 1 week after transplantation, while, when the same amount of cells was injected as suspension, no cells were detectable three days after injection. Cells from spheroids displayed the same engraftment capability when they were injected in cardiotoxin-injured myocardium. Our study shows that spherical in vivo ready-to-implant scaffold-less aggregates of hCPCs able to engraft also in the hostile environment of an injured myocardium can be produced with an economic, easy and fast protocol

Combination of chemotherapy and PD-1 blockade induces T cell responses to tumor non-mutated neoantigens

Here, we developed an unbiased, functional target-discovery platform to identify immunogenic proteins from primary non-small cell lung cancer (NSCLC) cells that had been induced to apoptosis by cisplatin (CDDP) treatment in vitro, as compared with their live counterparts. Among the multitude of proteins identified, some of them were represented as fragmented proteins in apoptotic tumor cells, and acted as non-mutated neoantigens (NM-neoAgs). Indeed, only the fragmented proteins elicited effective multi-specific CD4+ and CD8+ T cell responses, upon a chemotherapy protocol including CDDP. Importantly, these responses further increased upon anti-PD-1 therapy, and correlated with patients’ survival and decreased PD-1 expression. Cross-presentation assays showed that NM-neoAgs were unveiled in apoptotic tumor cells as the result of caspase-dependent proteolytic activity of cellular proteins. Our study demonstrates that apoptotic tumor cells generate a repertoire of immunogenic NM-neoAgs that could be potentially used for developing effective T cell-based immunotherapy across multiple cancer patients