The structural and optoelectronic properties of several substituted polyN-9′-heptadecanyl-2,7-carbazole-alt-5,5-(4′,7′-di-2-thienyl-2′,1′,3′-benzothiadiazole) (PCDTBT) conjugated oligomers have been ...investigated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT). Various electron-withdrawing and electron-donating groups were attached to the 5′ position of the benzothiadiazole unit in the PCDTBT oligomers. HOMO energies (EHOMO), LUMO energies (ELUMO), and the fundamental energy gaps (EGap) were calculated using DFT while the first singlet excited states (EOpt) were calculated using TD-DFT. Results show that the structural properties of the oligomers greatly affect the optoelectronic properties. Results also show that both electron-withdrawing and electron-donating groups are capable of lowering the EGap of PCDTBT. Several properties of substituted PCDTBT, which may affect the solar cell properties, were then calculated and compared with the calculated values for PCDTBT. From the calculated properties, PCDTBT-F showed improvement in the EGap, open-circuit voltage (VOC), and ionization potential (IP), which may lead to solar cells with improved power conversion efficiency (PCE) compared to PCDTBT.
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•Effect of chemical modifications on PCDTBT were studied by DFT and TD-DFT.•Large deviations in Φ and Δr in chemically modified PCDTBT greatly increases EGap and EOpt.•The EGap and EOpt of PCDTBT may be lowered by both electron-withdrawing and electron-donating substituents.•Coplanar thiophene and substituted benzothiadiazole units in PCDTBT derivatives may lead to increased light absorption.•PCDTBT-F may have superior solar cell properties: ISC, VOC, and IP, than PCDTBT.
Conventional quantum key distribution (QKD) typically uses binary encoding based on photon polarization or time-bin degrees of freedom and achieves a key capacity of at most one bit per photon. Under ...photon-starved conditions the rate of detection events is much lower than the photon generation rate, because of losses in long distance propagation and the relatively long recovery times of available single-photon detectors. Multi-bit encoding in the photon arrival times can be beneficial in such photon-starved situations. Recent security proofs indicate high-dimensional encoding in the photon arrival times is robust and can be implemented to yield high secure throughput. In this work we demonstrate entanglement-based QKD with high-dimensional encoding whose security against collective Gaussian attacks is provided by a high-visibility Franson interferometer. We achieve unprecedented key capacity and throughput for an entanglement-based QKD system because of four principal factors: Franson interferometry that does not degrade with loss; error correction coding that can tolerate high error rates; optimized time-energy entanglement generation; and highly efficient WSi superconducting nanowire single-photon detectors. The secure key capacity yields as much as 8.7 bits per coincidence. When optimized for throughput we observe a secure key rate of 2.7 Mbit s−1 after 20 km fiber transmission with a key capacity of 6.9 bits per photon coincidence. Our results demonstrate a viable approach to high-rate QKD using practical photonic entanglement and single-photon detection technologies.
Inflammation, cell adhesion to vascular endothelium, and endothelial injury contribute to sickle cell anemia (SCA) vaso‐occlusion. Although alterations in inflammatory cytokines and biomarkers have ...been related, reports have been conflicting, and a conclusive role for these molecules in the disease remains to be established. Furthermore, the effect of hydroxyurea therapy (HU) on the release of inflammatory mediators is not understood. This study aimed to determine plasma levels and leukocyte gene expressions of inflammatory mediators in healthy controls, steady‐state SCA patients, and SCA patients on HU therapy. TNF‐α, IL‐8, and PGE2 levels were significantly higher in the plasma of SCA individuals when compared with control individuals. HU therapy was associated with a significant reversal of augmented TNF‐α and, interestingly, increased plasma anti‐inflammatory IL‐10. IFN‐γ, IL‐10, cyclooxygenase 2 (COX‐2), and inducible NO synthase (iNOS) gene expressions were unaltered in SCA mononuclear cells (MC); however, gene expressions of TNF‐α, IL‐8, and the protective enzyme heme oxygenase‐1 (HO‐1) were significantly higher. HU therapy was not associated with significantly altered SCA MC inflammatory gene expression, although COX‐2 mRNA expression was decreased. In SCA neutrophils, gene expressions of IL‐8, IFN‐γ, iNOS, and HO‐1 were significantly higher than those of control subjects. Patients on HU demonstrated lower iNOS and higher IL‐10 neutrophil gene expressions. Taken together, data suggest that alterations in the gene expressions and productions of a number of pro‐ and anti‐inflammatory mediators are present in SCA and importantly, in those patients on HU therapy. Knowledge of these pathways may contribute to further the understanding of the pathophysiology of this disease.
Abstract Objective To identify clinical and neurocognitive predictors of long-term functional outcome in patients with bipolar disorder Methods A total of 32 subjects who met criteria for bipolar I ...or II disorder were recruited from the Barcelona Bipolar Disorder Program and were assessed clinically and neuropsychologically at baseline. After an average 4-year follow-up, they were interviewed with the Functioning Assessment Short Test (FAST) to assess functional outcome. Multivariate analyses were applied to identify clinical and neurocognitive predictors of functional outcome. Results The main regression model for predictors of overall psychosocial functioning identified subclinical depressive symptoms ( ß = 0.516, t = 3.51, p = 0.002), and free delayed recall in a verbal memory task ( ß = − 0.314, t = − 2.144, p = 0.041), accounting for 36% of the variance. Specific predictors of occupational functioning were, again, subthreshold depression ( ß = 0.435, t = 2.8, p = 0.009) and a measure of executive function, digits backwards ( ß = − 0.347, t = − 2.23, p = 0.034). This model explained around 28% of the variance (corrected R2 = 0.28; F = 6.38, gl = 2, p = 0.004). Conclusions Subdepressive symptomatology together with neurocognitive impairments related to verbal memory and executive functions are predictor variables of long-term functional outcome in bipolar disorder.
It is well known that the presence of comorbidities and age-related health issues may hide biochemical and metabolic features triggered by SARS-CoV-2 infection and other diseases associated to ...hypoxia, as they are by themselves chronic inflammatory conditions that may potentially disturb metabolic homeostasis and thereby negatively impact on COVID-19 progression. To unveil the metabolic abnormalities inherent to hypoxemia caused by COVID-19, we here applied gas chromatography coupled to mass spectrometry to analyze the main metabolic changes exhibited by a population of male patients less than 50 years of age with mild/moderate and severe COVID-19 without pre-existing comorbidities known to predispose to life-threatening complications from this infection. Several differences in serum levels of particular metabolites between normal controls and patients with COVID-19 as well as between mild/moderate and severe COVID-19 were identified. These included increased glutamic acid and reduced glutamine, cystine, threonic acid, and proline levels. In particular, using the entire metabolomic fingerprint obtained, we observed that glutamine/glutamate metabolism was associated with disease severity as patients in the severe COVID-19 group presented the lowest and higher serum levels of these amino acids, respectively. These data highlight the hypoxia-derived metabolic alterations provoked by SARS-CoV-2 infection in the absence of pre-existing co-morbidities as well as the value of amino acid metabolism in determining reactive oxygen species recycling pathways, which when impaired may lead to increased oxidation of proteins and cell damage. They also provide insights on new supportive therapies for COVID-19 and other disorders that involve altered redox homeostasis and lower oxygen levels that may lead to better outcomes of disease severity.
Several studies have stressed the importance of the microbiota in the maintenance of the gastrointestinal epithelium. Administration of probiotic bacteria, supplements composed of microbiota ...constituents, was previously shown to diminish symptoms in patients suffering from inflammatory bowel diseases. This raises the possibility that probiotics may play an active role in enhancing the intestinal barrier at the mucosal surface. In this study, we investigated whether the clinically tested VSL#3 probiotic formula and/or its secreted components can augment the protective mucus layer in vivo and in vitro. For in vivo studies, Wistar rats were orally administered the probiotic mixture VSL#3 on a daily basis for seven days. After treatment, basal luminal mucin content increased by 60%. In addition, we exposed isolated rat colonic loops to the VSL#3 probiotic formula, which significantly stimulated colonic mucin (MUC) secretion and MUC2 gene expression; however, MUC1 and MUC3 gene expression were only slightly elevated. The effect of the VSL#3 mucin secretagogue was also tested in vitro by use of LS 174T colonic epithelial cells. In contrast to the animal studies, cultured cells incubated with VSL#3 bacteria did not exhibit increased mucin secretion. However, the bacterial secreted products contained in the conditioned media stimulated a remarkable mucin secretion effect. Among the three bacterial groups (Lactobacilli, Bifidobacteria, and Streptococci) contained in VSL#3, the Lactobacillus species were the strongest potentiator of mucin secretion in vitro. A preliminary characterization of the putative mucin secretagogue suggested that it was a heat-resistant soluble compound, which is not sensitive to protease and DNase treatment. These findings contribute to a better understanding of the complex and beneficial interaction between colonic epithelial cells and intestinal bacteria.
Salmonella enterica subsp. enterica is one of the main food-borne pathogens. This microorganism combines an aerobic life outside the host with an anaerobic life within the host. One of the main ...concerns related to S. enterica is biofilm formation and cellulose production. In this study, biofilm formation, morphotype, cellulose production and transcription of biofilm and quorum sensing-related genes of 11 S. enterica strains were tested under three different conditions: aerobiosis, microaerobiosis, and anaerobiosis. The results showed an influence of oxygen levels on biofilm production. Biofilm formation was significantly higher (P<0.05) in aerobiosis than in microaerobiosis and anaerobiosis. Cellulose production and RDAR (red, dry, and rough) were expressed only in aerobiosis. In microaerobiosis, the strains expressed the SAW (smooth and white) morphotype, while in anaerobiosis the colonies appeared small and red. The expression of genes involved in cellulose synthesis (csgD and adrA) and quorum sensing (sdiA and luxS) was reduced in microaerobiosis and anaerobiosis in all S. enterica strains tested. This gene expression levels were less reduced in S. Typhimurium and S. Enteritidis compared to the tested serotypes. There was a relationship between the expression of biofilm and quorum sensing-related genes. Thus, the results from this study indicate that biofilm formation and cellulose production are highly influenced by atmospheric conditions. This must be taken into account as contamination with these bacteria can occur during food processing under vacuum or modified atmospheres.
•Biofilm formation, morphotype and gene expression in Salmonella is studied.•Three types of atmospheres were analyzed: aerobiosis, microaerobiosis, anaerobiosis.•Biofilm formation is decreased under microaerobiosis and anaerobiosis.•Morphotype was altered at the three different atmospheres.•Gene expression decreased under microaerobiosis and anaerobiosis.
Bottom waters of the northeast Pacific continental shelf naturally experience localized hypoxic conditions, with significant influences on food webs and biogeochemical cycling. In August 2021, ...extreme hypoxia was detected from several measurement platforms along the southern British Columbia continental shelf, with oxygen concentration <60 μmol kg−1, and a difference from the seasonal climatology of more than 2 standard deviations. Early and intense remote upwelling and local density shifts were associated with an anomalously strong spring phytoplankton bloom, which likely stimulated localized respiration of subsurface organic matter. This event was concurrent with unsuitable habitat for Pacific halibut and calcite and aragonite undersaturation throughout most of the water column. The drivers of this extreme low oxygen event could be enhanced under future climate change, with potentially significant impacts on marine ecology and biogeochemistry.
Plain Language Summary
Most marine organisms consume oxygen, and are therefore impacted when seawater oxygen concentrations reach low values. Extreme low oxygen concentrations are rare in the coastal waters of British Columbia, Canada. However, unusually strong oxygen depletion was observed off the coast of Vancouver Island during summer 2021. Unusually strong, early season upwelling winds along the California coast impacted Vancouver Island by causing nutrient‐rich water to be mixed into the surface, stimulating a large and earlier than usual spring phytoplankton bloom. Decomposition of the bloom‐derived organic carbon consumed local subsurface oxygen throughout the spring and summer. These subtle changes in timing and intensity of seasonal processes likely caused this low oxygen event, which was also associated with high concentrations of inorganic carbon, leading to ocean acidification. Such extreme low oxygen events, even if short‐lived, can have a significant impact on marine ecosystems, restricting the habitat available for groundfish species, such as Pacific halibut, and impacting the formation of carbonate shells by various organisms. The drivers of extreme low oxygen events are projected to intensify as climate change progresses.
Key Points
Widespread extreme hypoxia was observed throughout the water column along the southern British Columbia continental shelf in summer 2021
Early and intense upwelling followed by a strong biological response contributed to oxygen depletion in subsurface waters
Multiple indices suggest that this extreme event was concurrent with unsuitable habitat conditions for groundfish and calcifying organisms
A growing number of clinical trials explore the use of cell-based therapies for the treatment of disease and restoration of damaged tissue; however, limited cell survival and engraftment remains a ...significant challenge. As the field continues to progress, microencapsulation strategies are proving to be a valuable tool for protecting and supporting these cell therapies while preserving minimally invasive delivery. This work presents a novel, dual-photoinitiator technique for encapsulation of cells within hydrogel microspheres. A desktop vortexer was used to generate an emulsion of poly(ethylene glycol) diacrylate (PEGDA) or PEGDA-based precursor solution in mineral oil. Through an optimized combination of photoinitiators added to both the aqueous and the oil phase, rapid gelation of the suspended polymer droplets was achieved. The photoinitiator combination provided superior cross-linking consistency and greater particle yield, and required lower overall initiator concentrations compared with a single initiator system. When cells were combined with the precursor solution, these benefits translated to excellent microencapsulation yield with 60–80% viability for the tested cell types. It was further shown that the scaffold material could be modified with cell-adhesive peptides to be used as surface-seeded microcarriers, or additionally with enzymatically degradable sequences to support three-dimensional spreading, migration and long-term culture of encapsulated cells. Three cell lines relevant to neural stem cell therapies are demonstrated here, but this technology is adaptable, scalable and easy to implement with standard laboratory equipment, making it a useful tool for advancing the next generation of cell-based therapeutics.
The present study investigated the prevalence, antimicrobial resistance to twenty antibiotics, and class 1 integron and virulence genes of Salmonella isolated from poultry houses of broilers in ...northwestern Spain between 2011 and 2015. Strains were classified to the serotype level using the Kauffman-White typing scheme and subtyping with enterobacterial repetitive intergenic consensus PCR. The prevalence of Salmonella spp. was 1.02%. Sixteen different serotypes were found, with S. typhimurium and S. arizonae 48:z4, z23:- being the most prevalent. A total of 59.70% of strains were resistant to at least one, and 19.70% were resistant to multiple drugs. All Salmonella spp. were susceptible to cefotaxime, ciprofloxacin, gentamicin, kanamycin, levofloxacin, neomycin, and trimethoprim. The highest level of resistance was to sulfamethoxazole (40.29%), doxycycline (17.91%), and nalidixic acid (17.91%). None of the isolates carried class 1 integron and only isolates of S. enterica subspecies enterica were positive for all virulence factors tested, whereas S. arizonae lacked genes related to replication and invasion in nonphagocytic cells. This study demonstrates that the prevalence and antimicrobial resistance of Salmonella spp. in poultry houses of broilers of northwestern Spain is low compared with those found in other studies and in other steps of the food chain.
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