bluuebunny/crossref_metadata_2025_split huggingface dataset:
Extraction of microalgal starch and pigments by using different cell disruption methods and aqueous two‐phase system
Authors: Di Caprio Fabrizio , Chelucci Rachele , Francolini Iolanda , Altimari Pietro , Pagnanelli Francesca 
Published: September 2021

AbstractBACKGROUNDMicroalgae can synthesize starch with productivity higher than conventional terrestrial crops, without the need for arable land. However, little is known about processes to extract starch from microalgae. Here, a biorefinery process is described including microalgal cell disruption followed by extraction of starch and pigments with aqueous two‐phase system (ATPS) using choline chloride and polypropylene glycol 400. Sonication and bead milling were compared for cell disruption rate and starch extraction efficiency.RESULTSA first order kinetic model described well the cell disruption for both the methods, with a rate 2.6 times higher for bead milling than sonication. By applying ATPS on samples with comparable cell disruption (>93%), starch was separated better after sonication (67% recovery in the pellet) than after bead milling, for which it remained equally distributed between pellet (40%) and choline chloride phase. Pigments were extracted with 42–66% yield irrespective of the cell disruption method. Microalgal starch granules had a normal and narrow distribution for size (0.93 ± 0.14 μm) and a gelatinization temperature between 45–55 °C.CONCLUSIONFor the same cell disruption yield, different starch separation efficiencies can be achieved, depending on the cell disruption method applied. Although bead milling was faster than sonication in disrupting cells, it gave worst starch separation efficiency. The properties of the extracted microalgal starch indicate potential technical advantages, with respect to conventional starch sources, for applications in the bioplastic and food sector. © 2021 The Authors. Journal of Chemical Technology and Biotechnology published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry (SCI).
Seminal fluid and sperm diluent affect sperm metabolism in an insect: Evidence from NAD(P)H and flavin adenine dinucleotide autofluorescence lifetime imaging
Authors: Massino Christian , Wetzker Cornelia , Balvin Ondřej , Bartonicka Tomáš , Kremenova Jana , Sasinkova Markéta , Otti Oliver , Reinhardt Klaus 
Published: September 2021

AbstractSperm metabolism is fundamental to sperm motility and male fertility. Its measurement is still in its infancy, and recommendations do not exist as to whether or how to standardize laboratory procedures. Here, using the sperm of an insect, the common bedbug, Cimex lectularius, we demonstrate that standardization of sperm metabolism is required with respect to the artificial sperm storage medium and a natural medium, the seminal fluid. We used fluorescence lifetime imaging microscopy (FLIM) in combination with time‐correlated single‐photon counting (TCSPC) to quantify sperm metabolism based on the fluorescent properties of autofluorescent coenzymes, NAD(P)H and flavin adenine dinucleotide. Autofluorescence lifetimes (decay times) differ for the free and protein‐bound state of the co‐enzymes, and their relative contributions to the lifetime signal serve to characterize the metabolic state of cells. We found that artificial storage medium and seminal fluid separately, and additively, affected sperm metabolism. In a medium containing sugars and amino acids (Grace's Insect medium), sperm showed increased glycolysis compared with a commonly used storage medium, phosphate‐buffered saline (PBS). Adding seminal fluid to the sperm additionally increased oxidative phosphorylation, likely reflecting increased energy production of sperm during activation. Our study provides a protocol to measure sperm metabolism independently from motility, stresses that protocol standardizations for sperm measurements should be implemented and, for the first time, demonstrates that seminal fluid alters sperm metabolism. Equivalent protocol standardizations should be imposed on metabolic investigations of human sperm samples.
A protocol for single‐source dual‐pulse stimulated emission depletion setup with Bessel modulation
Authors: Xu Xinzhu , Zhao Kun , Ren Wei , Wu Zhaoyang , Yu Wentao , Shao Chendi , Shi Kebin , Xi Peng 
Published: September 2021

AbstractSTimulated Emission Depletion (STED) microscopy attains super‐resolution in biological imaging beyond the diffraction limit. Here, we give a concise protocol to construct a dual‐pulse STED setup with one super‐continuum laser. Moreover, a flexible and dismountable Bessel modulation module is introduced for potential 2D‐stack STED imaging. Experiments and notices are introduced in detail, with discussion on some important check‐points for STED, such as detector saturation. Finally, the results validate the system working.
Synthesis of new 1,4‐ and 1,5‐disubstituted N‐ethyl acetate and N‐α‐butyro‐γ‐lactone alkylimidazole derivatives as N‐acylhomoserine lactone analogs
Authors: Zhang Qiang , Li Si‐Zhe , Queneau Yves , Soulère Laurent 
Published: September 2021

AbstractNew alkylimidazoles functionalized with a homoserine lactone or an alkyloxycarbonyl moiety have been synthesized as N‐acylhomoserine lactones (AHLs) analogs. The 1,4‐disubstituted imidazole derivatives were prepared by alkylation of 4(5)‐alkylimidazoles with α‐bromo‐γ‐butyrolactone or ethyl α‐bromoacetate. An alternative route was preferred for the synthesis of their 1,5‐disubstituted counterparts based on the use of a N1‐protected alkylimidazole, its alkylation to an N3‐imidazolyl‐α‐acetate and deprotection to the desired 1,5‐disubstituted esters and subsequent alkylation of the acetate moiety with cyclic ethylene sulfate followed by acid‐catalyzed cyclization. The ability to modulate bacterial quorum sensing of all new compounds was compared to that of previously reported AHL analogs in which the amide bond is replaced by a heterocyclic group.
Absence of first‐pass isolation is associated with poor pulmonary vein isolation durability and atrial fibrillation ablation outcomes
Authors: Ninomiya Yuichi , Inoue Koichi , Tanaka Nobuaki , Okada Masato , Tanaka Koji , Onishi Toshinari , Hirao Yuko , Oka Takafumi , Inoue Hiroyuki , Takayasu Kohtaro , Nakamaru Ryo , Kitagaki Ryo , Koyama Yasushi , Okamura Atsunori , Iwakura Katsuomi , Ohishi Mitsuru , Fujii Kenshi 
Published: September 2021

AbstractBackgroundPulmonary vein (PV) reconnection is the main cause of atrial fibrillation (AF) recurrence. This study aimed to examine the effect of first‐pass PV isolation (PVI) on PV reconnection frequency during the procedure and on AF ablation outcomes.MethodsThis retrospective study included 446 patients with drug‐refractory AF (370 men, aged 64 ± 10 years) who underwent initial PVI using an open‐irrigated contact force catheter between January 2015 and October 2016. We investigated the effect of first‐pass PVI on PV reconnection during spontaneous PV reconnection and dormant conduction after an adenosine triphosphate challenge.ResultsFirst‐pass PVI was achieved in 69% (617/892) of ipsilateral PVs, of which we observed PV reconnection during the procedure in 134 (22%) PVs. This value was significantly lower than that observed in those without first‐pass PVI (50%, 138/275) (P < .0001). We divided the subjects into two groups based on the presence or absence of first‐pass PVI in at least one of two ipsilateral PVs: first‐pass (n = 383, 86%) and non‐first‐pass groups (n = 63, 14%). The 2‐year AF recurrence‐free rate was significantly higher in the first‐pass group than in the other group (75% vs 59%, log‐rank P = .032). In 78 patients with repeat AF ablation, the PV reconnection rate in the second procedure was significantly lower in PVs that had first‐pass isolation in the first procedure (34% vs 73%, P < .0001).ConclusionsAbsence of first‐pass PVI was associated with a higher frequency of spontaneous PV reconnection and dormant conduction and poor ablation outcomes. First‐pass isolation may be a useful marker for better PVI durability.
YfiF, an unknown protein, affects initiation timing of chromosome replication in Escherichia coli
Authors: GeZi GeZi , Liu Rui , Du Dongdong , Wu Nier , Bao Narisu , Fan Lifei , Morigen Morigen 
Published: September 2021

AbstractThe Escherichia coli YfiF protein is functionally unknown, being predicted as a transfer RNA/ribosomal RNA (tRNA/rRNA) methyltransferase. We find that absence of the yfiF gene delays initiation of chromosome replication and the delay is reversed by ectopic expression of YfiF, whereas excess YfiF causes an early initiation. A slight decrease in both cell size and number of origin per mass is observed in ΔyfiF cells. YfiF does not genetically interact with replication proteins such as DnaA, DnaB, and DnaC. Interestingly, YfiF is associated with ribosome modulation factor (RMF), hibernation promotion factor (HPF), and the tRNA methyltransferase TrmL. Defects in replication initiation of Δrmf, Δhpf, and ΔtrmL can be rescued by overexpression of YfiF, indicating that YfiF is functionally identical to RMF, HPF, and TrmL in terms of replication initiation. Also, YfiF interacts with the rRNA methyltransferase RsmC. Moreover, the total amount of proteins and DnaA content per cell decreases or increases in the absence of YfiF or the presence of excess YfiF. These facts suggest that YfiF is a ribosomal dormancy‐like factor, affecting ribosome function. Thus, we propose that YfiF is involved in the correct timing of chromosome replication by changing the DnaA content per cell as a result of affecting ribosome function.
Characterizing the tail behaviour of daily precipitation probability distributions over India using the obesity index
Authors: Gupta Neha , Chavan Sagar Rohidas 
Published: September 2021

AbstractExtreme precipitation events lie in the upper part of the probability distribution of daily precipitation data, that is, the tail. Depending upon the tail behaviour, various probability distributions are partitioned into heavy‐tailed and light‐tailed distributions. Heavy‐tails tend to approach zero less rapidly than light‐tails, signifying a higher frequency of occurrences for extreme precipitation events. Prediction of extreme precipitation depends on how reliably the distribution tail is modelled. Tail behaviour can be studied by graphical as well as threshold‐based fitting approaches. However, the graphical methods are time‐consuming and do not provide quantitative comparisons between two distributions, whereas the threshold‐based approaches possess limitations such as ambiguity in selecting an optimum threshold for demarcation of the tail. This article assesses the utility of a simple empirical index, that is, the “Obesity Index” (OB) to discern the probability distributions of daily gridded precipitation data with a resolution of 0.25° for historical (1951–2004) and future (2006–2099) periods over India into light‐ and heavy‐tailed. The OB‐based approach is an easy‐to‐use empirical approach that can quantitatively diagnose the heaviness of distribution tails without assuming any threshold for segregating the tails. Future projections of daily precipitation were obtained by downscaling simulations of the Coordinated Regional Climate Downscaling Experiment. Subsequently, a comparative analysis between the OB‐based approach and threshold‐based approaches by Nerantzaki and Papalexiou and Papalexiou et al. was conducted. Finally, the application of the OB‐based approach is extended to characterize daily precipitation in Indian Meteorological Subdivisions. Furthermore, we explored the dependence of the OB on the elevation of grids. Results indicated the applicability of heavy‐tailed distributions in the representation of daily precipitation over India and suggest an OB‐based approach as a good alternative diagnostic tool for assessing tail behaviour.
Barriers to nutrition therapy in the critically ill patient with COVID‐19
Authors: Suliman, Sally , McClave Stephen A. , Taylor Beth E. , Patel, Jayshil , Omer, Endashaw , Martindale, Robert G. 
Published: September 2021

AbstractBackgroundCoronavirus disease 2019 (COVID‐19) has created challenges for intensivists, as high ventilatory demands and prolonged hypermetabolism make it difficult to sustain nutrition status. The purpose of this survey was to determine current practices in nutrition therapy and identify barriers to its delivery.MethodsA survey about delivering nutrition therapy to critically ill patients with COVID‐19 was sent to clinicians at academic and community hospitals from September to December 2020.ResultsOf 440 who viewed the survey, 199 (45%) completed the questionnaire. Respondents were composed of 30%, physicians and 70% registered dietitians, with 51% representing community programs, 43% academic institutions, and 6% Veterans Affairs centers. Half (49%) had protocols for managing critically ill patients with COVID‐19, and 21% had a protocol for nutrition therapy. Although most respondents (83%) attempted to feed by the intragastric route, only 9% indicated that energy/protein needs were met. The biggest barriers to delivery of enteral nutrition (EN) involved the patients unpredictable clinical course and fear of aspiration given the lack of respiratory reserve. Intensivists were reluctant to add supplemental parenteral nutrition (PN) because of perceived lack of benefit.ConclusionThe survey results would suggest that strategies for nutrition therapy based on the intragastric infusion of EN are unsuccessful in meeting the energy/protein needs of critically ill patients with COVID‐19. It is likely these barriers exist in providing nutrition to non‐Covid‐19 critically ill patients. Intensivists need protocols that optimally deliver intragastric EN, consider early postpyloric infusion, and address adding supplemental PN in a deteriorating nutrition status.
Cytotoxic effects of dental calculus particles and freeze‐dried Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum on HSC‐2 oral epithelial cells and THP‐1 macrophages
Authors: Ziauddin S.M. , Alam Mohammad Ibtehaz , Mae Megumi , Oohira Masayuki , Higuchi Kanako , Yamashita Yasunori , Ozaki Yukio , Yoshimura Atsutoshi 
Published: September 2021

AbstractBackgroundPeriodontitis is an inflammatory disease initiated by dental deposits. Microorganisms in the dental biofilm induce cell death in epithelial cells, contributing to the breakdown of epithelial barrier function. Recently, dental calculus has also been implicated in pyroptotic cell death in oral epithelium. We analyzed the cytotoxic effects of dental calculus and freeze‐dried periodontopathic bacteria on oral epithelial cells and macrophages.MethodsHSC‐2 (human oral squamous carcinoma cells) and phorbol 12‐myristate 13‐acetate‒differentiated THP‐1 macrophages were exposed to dental calculus or one of two species of freeze‐dried bacterium, Aggregatibacter actinomycetemcomitans and Fusobacterium nucleatum. Following incubation for 24 hours, we measured cytotoxicity via lactate dehydrogenase release. Cells were then incubated with glyburide, an NLRP3 inflammasome inhibitor, to assess the potential role of pyroptosis. We also conducted a permeability assay to analyze the effects on epithelial barrier function.ResultsDental calculus induced dose‐dependent cell death in HSC‐2 cells, whereas cell death induced by freeze‐dried bacteria was insignificant. Conversely, freeze‐dried bacteria induced more cell death than dental calculus in THP‐1 macrophages. Cell death induced by dental calculus but not by freeze‐dried bacteria was inhibited by glyburide, indicating that these are different types of cell death. In the permeability assays, dental calculus but not freeze‐dried bacteria attenuated the barrier function of HSC‐2 cell monolayers.ConclusionDue to the low sensitivity of HSC‐2 cells to microbial cytotoxicity, dental calculus had stronger cytotoxic effects on HSC‐2 cell monolayers than freeze‐dried A. actinomycetemcomitans and F. nucleatum, suggesting that it plays a critical role in the breakdown of crevicular/pocket epithelium integrity.
Cathodoluminescence, Raman and scanning electron microscopy with energy dispersion system mapping to unravel the mineralogy and texture of an altered CaAl‐rich inclusion in Renazzo CR2 carbonaceous chondrite
Authors: Tribaudino Mario , Bersani Danilo , Mantovani Luciana , Pizzati Mattia , Salviati Giancarlo 
Published: September 2021

AbstractAn altered fluffy type A CaAl‐rich inclusion in the CR2 Renazzo carbonaceous chondrite was examined by combined Raman, scanning electron microscopy with energy dispersion system (SEM‐EDS) and cathodoluminescence (CL) mapping. Blue CL at 450 nm and orange emission at 600 nm were related to anorthite and calcite, respectively. Raman spectra were highly fluorescent, and only the stronger peaks of anorthite, clinopyroxene and calcite were observed. Raman‐induced fluorescence emission was measured using the 632‐nm Raman laser source, up to 850 nm, and used to chart the mineral phases. A fluorescence structured peak at 690 nm, split in three subpeaks at 678, 689 and 693 nm, was found; it is likely related to the fluorescence emission of Cr3+ from a fassaitic pyroxene in anorthite. Secondary pyroxene in the Wark–Lovering rim does not show the peak at 690 nm; the different fluorescence emission from the secondary rim and the pyroxene patches within anorthite could be a marker to spot the primary pyroxene. From combined imaging, the events in the altered chondrite could be sequenced. Starting from a pristine assemblage of spinel and melilite, with little fassaite, several alteration episodes occurred. Alteration in secondary anorthite, which could be mapped by the blue CL emission at 450 nm, was followed by alkalization, with rims of sodalite and nepheline, and subsequent formation of secondary clinopyroxene, encircling the inclusion. Widespread calcite alteration, present also in the matrix between chondrules, was the last recorded event.
Stratifying the Risk of Cardiovascular Disease in Obstructive Sleep Apnea Using Machine Learning
Authors: Gourishetti Saikrishna C. , Taylor Rodney , Isaiah Amal 
Published: September 2021

Objectives/HypothesisObstructive sleep apnea (OSA) is associated with higher risk of morbidity and mortality related to cardiovascular disease (CVD). Due to overlapping clinical risk factors, identifying high‐risk patients with OSA who are likely to develop CVD remains challenging. We aimed to identify baseline clinical factors associated with the future development of CVD in patients with OSA.Study DesignRetrospective analysis of prospectively collected data.MethodsWe performed a retrospective analysis of 967 adults aged 45 to 84 years and enrolled in the Multi‐Ethnic Study of Atherosclerosis. Six machine learning models were created using baseline clinical factors initially identified by stepwise variable selection. The performance of these models for the prediction of additional risk of CVD in OSA was calculated. Additionally, these models were evaluated for interpretability using locally interpretable model‐agnostic explanations.ResultsOf the 967 adults without baseline OSA or CVD, 116 were diagnosed with OSA and CVD and 851 with OSA alone 10 years after enrollment. The best performing models included random forest (sensitivity 84%, specificity 99%, balanced accuracy 91%) and bootstrap aggregation (sensitivity 84%, specificity 100%, balanced accuracy 92%). The strongest predictors of OSA and CVD versus OSA alone were fasting glucose >91 mg/dL, diastolic pressure >73 mm Hg, and age >59 years.ConclusionIn the selected study population of adults without OSA or CVD at baseline, the strongest predictors of CVD in patients with OSA include fasting glucose, diastolic pressure, and age. These results may shape a strategy for cardiovascular risk stratification in patients with OSA and early intervention to mitigate CVD‐related morbidity.Level of Evidence3 Laryngoscope, 132:234–241, 2022
Enzyme‐ and UV‐Mediated Double‐Network Hybrid Hydrogels for 3D Cell Culture application
Authors: Li Xiao‐Pei , Zou Lin , Abodunrin Oluwatosin David , Wang Xiao‐Wei , Huang Ning‐Ping 
Published: September 2021

AbstractThree‐dimensional (3D) cell culture using hydrogel scaffolds can closely resemble the natural extracellular matrix (ECM), which offers appropriate mechanical support for cells and regulates cellular behavior. In this study, a bacterial transpeptidase sortase A (SA) is used to prepare enzymatically cross‐linked methacrylated hyaluronic acid (HA) peptides (HAMA‐P) hydrogel, which reveals fast gel kinetics under high SA cross‐linking concentrations and can be used as an injection hydrogel for tissue repair or extrusive 3D bioprinting. Furthermore, methacrylated gelatin (GelMA) is introduced to build the hybrid hydrogel (HAMA‐P‐GelMA) with double cross‐linking of enzyme‐UV, which has shown proper physical properties (mechanical properties, swelling, degradation rate, etc.) of the hydrogel matrix, and displayed desirable effects on cell viability, adhesion, and cell spreading, when compared to GelMA or HAMA‐P single‐network hydrogels. The HAMA‐P‐GelMA hybrid hydrogels provide a favorable 3D milieu for cell growth and can be used as a 3D bio‐ink or a carrier of stem cells/cytokines for injectable tissue repair and filling.
An Epoxy Adhesive Crosslinked through Radical‐Induced Cationic Frontal Polymerization
Authors: Turani Matteo , Baggio Andrea , Casalegno Valentina , Salvo Milena , Sangermano Marco 
Published: September 2021

AbstractUV‐initiated cationic frontal polymerization is exploited as a solvent‐free, extremely fast, and low‐temperature technique to obtain epoxy‐based adhesives. Epoxy formulations are prepared by blending commercial resins at different weight ratios and adding photo and thermal initiators at different percentages. In addition, the influence of other critical parameters, including the joint thickness, the nature of the adherends, and the temperature, is studied. As the reaction front is thermally sustained, the boundary conditions play a key role during the curing process and heat dissipation through the adherends in particular. The thermal properties of the epoxy formulation are studied through differential scanning calorimetry analysis, and the joint strengths are investigated by carrying out single lap off‐set shear tests under compression. The results demonstrate the feasibility of obtaining joints by means of the radical induced cationic frontal polymerization of the epoxy adhesives, which exhibit comparable epoxy group conversion and mechanical performances to the ones cured by traditional energy‐intensive techniques.