bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Decisive Role of Spin States and Spin Coupling in Dictating Selective O2 Adsorption in Chromium(II) Metal–Organic Frameworks**
Authors: Jose Reshma , Kancharlapalli Srinivasu , Ghanty Tapan K. , Pal Sourav , Rajaraman Gopalan 
Published: January 2022

AbstractThe coordinatively unsaturated chromium(II)‐based Cr3[(Cr4Cl)3(BTT)8]2 (Cr−BTT; BTT3−=1,3,5‐benzenetristetrazolate) metal–organic framework (MOF) has been shown to exhibit exceptional selectivity towards adsorption of O2 over N2/H2. Using periodic density functional theory (DFT) calculations, we attempted to decipher the origin of this puzzling selectivity. By computing and analyzing the magnetic exchange coupling, binding energies, the partial density of states (pDOS), and adsorption isotherms for the pristine and gas‐bound MOFs [(Cr4(X)4Cl)3(BTT)8]3− (X=O2, N2, and H2), we unequivocally established the role of spin states and spin coupling in controlling the gas selectivity. The computed geometries and gas adsorption isotherms are consistent with the earlier experiments. The binding of O2 to the MOF follows an electron‐transfer mechanism resulting in a CrIII superoxo species (O2.−) with a very strong antiferromagnetic coupling between the two centers, whereas N2/H2 are found to weakly interact with the metal center and hence only slightly perturb the associated coupling constants. Although the gas‐bound and unbound MOFs have an S=0 ground state (GS), the nature of spin the configurations and the associated magnetic exchanges are dramatically different. The binding energy and the number of oxygen molecules that can favorably bind to the Cr center were found to vary with respect to the spin state, with a significant energy margin (47.6 kJ mol−1). This study offers a hitherto unknown strategy of using spin state/spin couplings to control gas adsorption selectivity in MOFs.
Highly Selective Lysine Acylation in Proteins Using a Lys‐His Tag Sequence
Authors: Kofoed Christian , Wu Shunliang , Sørensen Kasper K. , Treiberg Tuule , Arnsdorf Johnny , Bjørn Sara P. , Jensen Tanja L. , Voldborg Bjørn G. , Thygesen Mikkel B. , Jensen Knud J. , Schoffelen Sanne 
Published: January 2022

AbstractChemical modification of proteins has numerous applications, but it has been challenging to achieve the required high degree of selectivity on lysine amino groups. Recently, we described the highly selective acylation of proteins with an N‐terminal Gly‐His6 segment. This tag promoted acylation of the N‐terminal Nα‐amine resulting in stable conjugates. Herein, we report the peptide sequences Hisn‐Lys‐Hism, which we term Lys‐His tags. In combination with simple acylating agents, they facilitate the acylation of the designated Lys Nϵ‐amine under mild conditions and with high selectivity over native Lys residues. We show that the Lys‐His tags, which are 7 to 10 amino acids in length and still act as conventional His tags, can be inserted in proteins at the C‐terminus or in loops, thus providing high flexibility regarding the site of modification. Finally, the selective and efficient acylation of the therapeutic antibody Rituximab, pure or mixed with other proteins, demonstrates the scope of the Lys‐His tag acylation method.
Influence of Substituents in the Benzene Ring on the Halogen Bond of Iodobenzene with Ammonia
Authors: Scheiner Steve , Hunter Sarah 
Published: January 2022

AbstractThe effects on the C−I⋅⋅N halogen bond between iodobenzene and NH3 of placing various substituents on the phenyl ring are monitored by quantum calculations. Substituents R=N(CH3)2, NH2, CH3, OCH3, COCH3, Cl, F, COH, CN, and NO2 were each placed ortho, meta, and para to the I. The depth of the σ‐hole on I is deepened as R becomes more electron‐withdrawing which is reflected in a strengthening of the halogen bond, which varied between 3.3 and 5.5 kcal mol−1. In most cases, the ortho placement yields the largest perturbation, followed by meta and then para, but this trend is not universal. Parallel to these substituent effects is a progressive lengthening of the covalent C−I bond. Formation of the halogen bond reduces the NMR chemical shielding of all three nuclei directly involved in the C−I⋅⋅N interaction. The deshielding of the electron donor N is most closely correlated with the strength of the bond, as is the coupling constant between I and N, so both have potential use as spectroscopic measures of halogen bond strength.
Mechanisms of Methylenecyclobutane Hydrogenation over Supported Metal Catalysts Studied by Parahydrogen‐Induced Polarization Technique
Authors: Salnikov Oleg G. , Burueva Dudari B. , Kovtunova Larisa M. , Bukhtiyarov Valerii I. , Kovtunov Kirill V. , Koptyug Igor V. 
Published: January 2022

AbstractIn this work the mechanism of methylenecyclobutane hydrogenation over titania‐supported Rh, Pt and Pd catalysts was investigated using parahydrogen‐induced polarization (PHIP) technique. It was found that methylenecyclobutane hydrogenation leads to formation of a mixture of reaction products including cyclic (1‐methylcyclobutene, methylcyclobutane), linear (1‐pentene, cis‐2‐pentene, trans‐2‐pentene, pentane) and branched (isoprene, 2‐methyl‐1‐butene, 2‐methyl‐2‐butene, isopentane) compounds. Generally, at lower temperatures (150–350 °C) the major reaction product was methylcyclobutane while higher temperature of 450 °C favors the formation of branched products isoprene, 2‐methyl‐1‐butene and 2‐methyl‐2‐butene. PHIP effects were detected for all reaction products except methylenecyclobutane isomers 1‐methylcyclobutene and isoprene implying that the corresponding compounds can incorporate two atoms from the same parahydrogen molecule in a pairwise manner in the course of the reaction in particular positions. The mechanisms were proposed for the formation of these products based on PHIP results.
Two‐Dimensional Metal–Organic Framework Nanosheets: Synthesis and Applications in Electrocatalysis and Photocatalysis
Authors: Liu Ya‐Long , Liu Xiang‐Yue , Feng Li , Shao Lan‐Xing , Li Si‐Jun , Tang Jing , Cheng Hu , Chen Zhuo , Huang Rui , Xu Hai‐Chao , Zhuang Jin‐Liang 
Published: January 2022

AbstractTwo‐dimensional metal–organic nanosheets (2D MONs) are an emerging class of ultrathin, porous, and crystalline materials. The organic/inorganic hybrid nature offers MONs distinct advantages over other inorganic nanosheets in terms of diversity of organic ligands and metal notes. Compared to bulk three‐dimensional metal–organic frameworks, 2D MONs possess merits of high density and readily accessible catalytic sites, reduced diffusion pathways for reactants/products, and fast electron transport. These features endow MONs with enhanced physical/chemical properties and are ideal for heterogeneous catalysis. In this Review, state‐of‐the‐art synthetic methods for the fabrication of 2D MONs were summarized. The advances of 2D MONs‐based materials for electrocatalysis and photocatalysis, including hydrogen evolution reaction (HER), oxygen evolution reaction (OER), oxygen reduction reaction (ORR), carbon dioxide reduction reaction (CO2RR), and electro‐/photocatalytic organic transformations were systematically discussed. Finally, the challenges and perspectives regarding future design and synthesis of 2D MONs for high‐performance electrocatalysis and photocatalysis were provided.
Methionine oxidation of CLK4 promotes the metabolic switch and redox homeostasis in esophageal carcinoma via inhibiting MITF selective autophagy
Authors: Shen Yaxing , Zhang Heng , Yao Shihua , Su Feng , Wang Hao , Yin Jun , Fang Yong , Tan Lijie , Zhang Kaiguang , Fan Xiangshan , Zhong Ming , Zhou Qingxin , He Jie , Zhang Zhiyong 
Published: January 2022

AbstractBackgroundMetabolic reprogramming and redox homeostasis contribute to esophageal squamous cell carcinoma (ESCC). CDC‐like kinase 4 (CLK4) is a dual‐specificity kinase that can phosphorylate substrates’ tyrosine or serine/threonine residue. However, the role and mechanism of CLK4 in ESCC remain unknown.MethodsCLK4 expression was analysed using publicly available datasets and confirmed in ESCC tissues and cell lines. The biological roles of CLK4 were studied with gain and loss‐of‐function experiments. Mass spectrometry was employed to examine the effects of CLK4 on metabolic profiling. In vitro kinase assay, co‐immunoprecipitation, glutathione S‐transferase pulldown, chromatin immunoprecipitation and luciferase reporter were used to elucidate the relationship among CLK4, microphthalmia‐associated transcription factor (MITF), COP1 and ZRANB1.ResultsCLK4 down‐regulation was observed in ESCC cell lines and clinical samples and associated with the methylation of its promoter. Low levels of CLK4 promoted ESCC development by affecting the purine synthesis pathway and nicotinamide adenine dinucleotide phosphate (NADPH)/nicotinamide adenine dinucleotide phosphate (NADP+) ratio. Interestingly, CLK4 inhibited ESCC development by blocking MITF‐enhanced de novo purine synthesis and redox balance. Mechanistically, wild type CLK4 (WT‐CLK4) but not kinase‐dead CLK4‐K189R mutant phosphorylated MITF at Y360. This modification promoted its interaction with E3 ligase COP1 and its K63‐linked ubiquitination at K308/K372, leading to sequestosome 1 recognition and autophagic degradation. However, the deubiquitinase ZRANB1 rescued MITF ubiquitination and degradation. In turn, MITF bound to E‐ rather than M‐boxes in CLK4 promoter and transcriptionally down‐regulated its expression in ESCC. Clinically, the negative correlations were observed between CLK4, MITF, and purine metabolic markers, which predicts a poor clinical outcome of ESCC patients. Notably, CLK4 itself was a redox‐sensitive kinase, and its methionine oxidation at M307 impaired kinase activity, enhanced mitochondria length and inhibited lipid peroxidation, contributing to ESCC.ConclusionsOur data highlight the potential role of CLK4 in modulating redox status and nucleotide metabolism, suggesting potential therapeutic targets in ESCC treatment.
Validation of a new multiparametric protocol to assess viability, acrosome integrity and mitochondrial activity in cooled and frozen thawed boar spermatozoa
Authors: Gonzalez‐Castro Raul A. , Peña Fernando J. , Herickhoff Lisa A. 
Published: January 2022

AbstractBackgroundMotility, morphology, membrane integrity and DNA fragmentation are sperm characteristics routinely used to assess quality of boar spermatozoa. However, the evaluation of individual parameters has intrinsic restrictions in the estimation of potential fertility. Therefore, we aimed to validate a new multiparametric protocol to assess fertility potential through the evaluation of viability, acrosome integrity and mitochondrial activity within the same sperm population for cooled and frozen–thawed boar spermatozoa.MethodThree multicolor protocols to assess viability, acrosome integrity and/or mitochondrial activity were compared for agreement containing two dyes (HM‐panel; Hoechst 33342, MitoTracker™ Deep Red), three dyes (3‐panel; SYBR®14, propidium iodide and lectin PNA‐Alexa™ 647) or four dyes (4‐panel; Hoechst 33342, lectin PNA‐Alexa™ 488, propidium iodide and MitoTracker™ Deep Red). Cooled (n = 132) and frozen–thawed (n = 254) samples of boar spermatozoa were assessed by flow cytometry.Results4‐Panel enabled the detection of several sperm subpopulations based on plasma membrane integrity, acrosome status and mitochondrial activity in cooled and frozen–thawed spermatozoa. No significant differences were observed between 3‐panel and 4‐panel for the percentage of live, live‐acrosome intact, and dead‐acrosome reacted spermatozoa. However, the percentage of acrosome‐intact spermatozoa was significantly higher in cooled samples when stained by 3‐panel than 4‐panel. Percentages of sperm parameters between protocols were strongly correlated, and agreement analysis demonstrated that both assays resulted in similar values for both sperm sample type.ConclusionOur results indicate that a four‐color protocol is a practical, simple and reliable procedure to simultaneously evaluate boar sperm viability, acrosome integrity and mitochondrial activity under clinical conditions.
Effect of colorectal cancer screening on long‐term survival of colorectal cancer patients: Results of the Korea National Cancer Screening Program
Authors: Luu Xuan Quy , Lee Kyeongmin , Jun Jae Kwan , Suh Mina , Jung Kyu‐Won , Choi Kui Son 
Published: January 2022

AbstractThe Korea National Cancer Screening Program (KNCSP) provides fecal immunochemical test‐based colorectal cancer (CRC) screening for people aged ≥50 years. Our study aimed to investigate the long‐term survival effects of CRC screening based on screening history and interval time since screening. The study cohort was obtained by linking three national databases, namely the Korea Central Cancer Registry, KNCSP database and Death Certificate. We included 32 509 CRC patients diagnosed in 2008 to 2009, who underwent CRC screening via the KNCSP between 2004 and 2009. The patients were followed‐up until 2019, and their survival was assessed according to their CRC screening history. Cox proportional hazards regression was used to compare time to deaths among CRC patients according to CRC screening history, after adjusting for covariates. Of the 32 509 patients, 20 022 (61.5%) patients were alive by the end of 2019. Long‐term survival was significantly higher among screened patients (68.2%) than nonscreened (57.2%) individuals. Compared to never‐screened patients, the hazard ratio (HR) for CRC‐specific death in screened patients was 0.77 (95% CI%, 0.73‐0.80). Lowest HR was observed in screened, localized CRC patients (HR, 0.48; 95% CI, 0.42‐0.56); HR for CRC‐specific death was the lowest in patients screened within 12 months of diagnosis (HR, 0.70; 95% CI, 0.66‐0.74), following which, the HRs increased with increasing time interval. CRC screening was positively associated with favorable prognosis in CRC patients aged 50 to 79 years. The effects on long‐term survival according to interval time was the best among individuals screened within 1 year before diagnosis.
Pregnancy‐associated plasma protein‐A (PAPP‐A) is a key component of an interactive cellular mechanism promoting pulmonary fibrosis
Authors: Bale Laurie K. , Schafer Marissa J. , Atkinson Elizabeth J. , Le Brasseur Nathan K. , Haak Andrew J. , Oxvig Claus , Conover Cheryl A. 
Published: January 2022

AbstractIdiopathic pulmonary fibrosis (IPF) is a progressive lung disease with few effective treatment options. We found a highly significant correlation between pregnancy‐associated plasma protein (PAPP)‐A expression in IPF lung tissue and disease severity as measured by various pulmonary and physical function tests. PAPP‐A is a metalloproteinase that enhances local insulin‐like growth factor (IGF) activity. We used primary cultures of normal adult human lung fibroblasts (NHLF) to test the hypothesis that PAPP‐A plays an important role in the development of pulmonary fibrosis. Treatment of NHLF with pro‐fibrotic transforming growth factor (TGF)‐β stimulated marked increases in IGF‐I mRNA expression (>20‐fold) and measurable IGF‐I levels in 72‐h conditioned medium (CM). TGF‐β treatment also increased PAPP‐A levels in CM fourfold (p = 0.004) and proteolytic activity ~2‐fold. There was an indirect effect of TGF‐β to stimulate signaling through the PI3K/Akt pathway, which was significantly inhibited by both IGF‐I‐inactivating and PAPP‐A inhibitory antibodies. Induction of senescence in NHLF increased PAPP‐A levels in CM 10‐fold (p = 0.006) with attendant increased proteolytic activity. Thus, PAPP‐A is a novel component of the senescent lung fibroblast secretome. In addition, NHLF secreted extracellular vehicles (EVs) with surface‐bound active PAPP‐A that were increased fivefold with senescence. Regulation of PAPP‐A and IGF signaling by TGF‐β and cell senescence suggests an interactive cellular mechanism underlying the resistance to apoptosis and the progression of fibrosis in IPF. Furthermore, PAPP‐A‐associated EVs may be a means of pro‐fibrotic, pro‐senescent communication with other cells in the lung and, thus, a potential therapeutic target for IPF.
Prognostic utility of self‐reported sarcopenia (SARC‐F) in the Multiethnic Cohort
Authors: Wu Anna H. , Setiawan V. Wendy , Lim Unhee , Tseng Chiu‐Cheng , White Kami K. , Shepherd John , Lenz Heinz Josef , Cheng Iona , Stram Daniel O. , Haiman Christopher , Wilkens Lynne R. , Le Marchand Loïc 
Published: January 2022

AbstractBackgroundAge‐related loss in skeletal muscle mass, quality, and strength, known as sarcopenia, is a well‐known phenomenon of aging and is determined clinically using methods such as dual‐energy X‐ray absorptiometry (DXA). However, these clinical methods to measure sarcopenia are not practical for population‐based studies, and a five‐question screening tool known as SARC‐F has been validated to screen for sarcopenia.MethodsWe investigated the relationship between appendicular skeletal lean mass/height2 (ALM/HT2) (kg/m2) assessed by DXA and SARC‐F in a subset of 1538 (778 men and 760 women) participants in the Multiethnic Cohort (MEC) Study after adjustment for race/ethnicity, age, and body mass index (BMI) at the time of DXA measurement. We then investigated the association between SARC‐F and mortality among 71 283 (41 757 women and 29 526 men) participants in the MEC, who responded to the five SARC‐F questions on a mailed questionnaire as part of the MEC follow‐up in 2012–2016.ResultsIn women, SARC‐F score was significantly inversely associated with ALM/HT2 after adjusting for race/ethnicity, and age and BMI at DXA (r = −0.167, P < 0.001); the result was similar in men although it did not reach statistical significance (r = −0.056, P = 0.12). Among the 71 000+ MEC participants, SARC‐F score ≥ 4, as an indicator of sarcopenia, was higher in women (20.9%) than in men (11.2%) (P < 0.0001) and increased steadily with increasing age (6.3% in <70 vs. 41.3% in 90+ years old) (P < 0.0001). SARC‐F score ≥ 4 was highest among Latinos (30.8% in women and 16.1% in men) and lowest in Native Hawaiian women (15.6%) and Japanese American men (8.9%). During an average of 6.8 years of follow‐up, compared with men with SARC‐F score of 0–1 (indicator of no sarcopenia), men with SARC‐F 2–3 (indicator of pre‐sarcopenia) and SARC‐F ≥ 4 had significantly increased risk of all‐cause mortality [hazard ratio (HR) = 1.00, 1.77, 3.73, P < 0.001], cardiovascular disease (CVD) mortality (HR = 1.00, 1.85, 3.98, P < 0.001), and cancer mortality (HR = 1.00, 1.46, 1.96, P < 0.001) after covariate adjustment. Comparable risk association patterns with SARC‐F scores were observed in women (all‐cause mortality: HR = 1.00, 1.47, 3.10, P < 0.001; CVD mortality: HR = 1.00, 1.59, 3.54, P < 0.001; cancer mortality: HR = 1.00, 1.30, 1.77, P < 0.001). These significant risk patterns between SARC‐F and all‐cause mortality were found across all sex–race/ethnic groups considered (12 in total).ConclusionsAn indicator of sarcopenia, determined using SARC‐F, showed internal validity against DXA and displayed racial/ethnic and sex differences in distribution. SARC‐F was associated with all‐cause mortality as well as cause‐specific mortality.
Greenhouse gas emissions and C costs of N release associated with cover crop decomposition are plant specific and depend on soil moisture: A microcosm study
Authors: Oliveira Dener M. S. , Pimentel Laisa G. , Barreto Matheus S. C. , Weiler Douglas A. , Bayer Cimélio 
Published: January 2022

AbstractCover cropping is used to improve soil quality and increase N inputs in agricultural systems, but it also may enhance greenhouse gases (GHG) emissions. Here, a 47‐d incubation study was conducted to track the decomposition process and evaluate GHG emissions and its drivers and to calculate the C costs of residue‐derived N released following the addition of residues from cover crops (pigeon pea, cowpea, lablab bean, vetch, and black oat) and maize under two water‐filled pore space (WFPS) levels (40 and 70%). For both WFPS levels, the increase in cumulative CO2 fluxes in plots that received residues is mainly related with the increment of potentially mineralizable C. Crop residues increased the global warming potential (GWP) under both WFPS levels, with CO2 emissions accounting for ≥98% of the GWP at 40% WFPS. At 70% WFPS, the GPW increment was driven by a notable increase in N2O emissions. The contribution of CH4 in the GWP emissions was negligible for all the crop residues evaluated. Principal component analysis highlighted that the optimal conditions for production and release are specific for each GHG. The cleaner N source was cowpea at 40% WFPS, which produced only 17.7 kg CO2‐eq kg–1 N mineralized, compared with vetch residues, which produced 233 kg CO2‐eq kg–1 N mineralized. To integrate agronomic and climate change mitigation perspectives, we suggest considering the C costs of the residue‐N released when choosing a cover crop.
Strong edge colorings of graphs and the covers of Kneser graphs
Authors: Lužar Borut , Máčajová Edita , Škoviera Martin , Soták Roman 
Published: January 2022

AbstractA proper edge coloring of a graph is strong if it creates no bichromatic path of length three. It is well known that for a strong edge coloring of a ‐regular graph at least colors are needed. We show that a ‐regular graph admits a strong edge coloring with colors if and only if it covers the Kneser graph . In particular, a cubic graph is strongly 5‐edge‐colorable whenever it covers the Petersen graph. One of the implications of this result is that a conjecture about strong edge colorings of subcubic graphs proposed by Faudree et al. is false.
Cytosolic dsRNA improves neonatal innate immune responses to adjuvants in use in pediatric vaccines
Authors: Brennan Kiva , Craven Simon , Cheung Maria , Kane Daniel , Noone Eleanor , O'Callaghan Joseph , Molloy Eleanor J , Walsh Patrick T , McAuliffe Fionnuala M , Doyle Sarah L 
Published: January 2022

AbstractPattern recognition receptors (PRRs) of the innate immune system represent the critical front-line defense against pathogens, and new vaccine formulations target these PRR pathways to boost vaccine responses, through activation of cellular/Th1 immunity. The majority of pediatric vaccines contain aluminum (ALUM) or monophosphoryl lipid A (MPLA) as adjuvants to encourage immune activation. Evidence suggests that elements of the innate immune system, currently being targeted for vaccine adjuvanticity do not fully develop until puberty and it is likely that effective adjuvants for the neonatal and pediatric populations are being overlooked due to modeling of responses in adult systems. We recently reported that the activity of the cytosolic nucleic acid (CNA) sensing family of PRRs is strong in cord blood and peripheral blood of young children. This study investigates the function of CNA sensors in subsets of neonatal innate immune cells and shows that myeloid cells from cord blood can be activated to express T cell costimulatory markers, and also to produce Th1 promoting cytokines. CD80 and CD86 were consistently up-regulated in response to cytosolic Poly(I:C) stimulation in all cell types examined and CNA activation also induced robust Type I IFN and low levels of TNFα in monocytes, monocyte-derived macrophages, and monocyte-derived dendritic cells. We have compared CNA activation to adjuvants currently in use (MPLA or ALUM), either alone or in combination and found that cytosolic Poly(I:C) in combination with MPLA or ALUM can improve expression of activation marker levels above those observed with either adjuvant alone. This may prove particularly promising in the context of improving the efficacy of existing ALUM- or MPLA-containing vaccines, through activation of T cell-mediated immunity.