bluuebunny/crossref_metadata_2025_split huggingface dataset:
All organic polyimide‐based composite films with high intrinsic polarization for superior energy density and low dielectric loss
Authors: Wang Yu , Yang Wenlong , Lin Jiaqi , Liu Xinmei , Zuo Yuhang , Sun Hongguo , Yang Ying , He Xunjun 
Published: May 2023

AbstractA simple and low‐cost approach was proposed to fabricate poly(vinylidene fluoride) (PVDF) and polyimide‐poly(amidic acid) (PI‐PAA) all‐organic hybrid films with excellent dielectric performance by solution casting and thermal imidization process. The results showed that the introduction of PVDF and PAA molecular chains into PI matrix significantly enhanced the dielectric permittivity and energy density of PI‐based composites. The permittivity and energy density of 15 wt% PI‐PAA/PVDF composites were 4.83 at 103 Hz and 5.55 J cm−3, which were 52% and 107% higher than that of PI (3.18 at 103 Hz, 2.68 J cm−3). In addition, the dielectric loss of 15 wt% PI‐PAA/PVDF composites was still maintained at a low level (0.009 at 103 Hz). The molecular dynamics results showed that the polarization strength of composites mainly originated from the intrinsic polarization strength. The intrinsic polarization strength of PI‐PAA/PVDF in the composites was 1010 times higher than interfacial polarization strength, and interfacial polarization was negligible. There was no significant difference between the self‐diffusion coefficients of 15 wt% PI‐PAA/PVDF and PI‐PAA, indicating that the relaxation polarization of polymer molecular chains was suppressed. This work provides an effective way for the preparation of dielectric for all organic high voltage direct current system.
Facile fabrication of highly interconnected poly(lactic acid)‐based scaffolds with good hydrophilicity using supercritical carbon dioxide
Authors: Chen Jinwei , Yang Ling , Chen Dahua , Wang Meigui , Wu Lixuan 
Published: May 2023

AbstractHighly interconnected poly(lactic acid) (PLA)‐based foams are extensively utilized to be candidate porous scaffolds in the field of tissue engineering. Nonetheless, it remains challenging about the preparation of highly porous, interconnected and hydrophilic PLA‐based scaffolds through a facile and cheap method. The present work synthesized PLA‐based scaffolds with high porosity through supercritical carbon dioxide (sc‐CO2) foaming strategy. For improving PLA foam interconnection as well as hydrophilicity, poly(butylene succinate) (PBS), and poly(ethylene glycol) (PEG) were chosen to be excellent additives for PLA blending. PEG acted as a compatibilizer between PLA and PBS, which enhanced open cell structure generation by decreasing melt viscosity. According to investigation of PBS and PEG content as well as foaming temperature, PLA/PBS/PEG(90/10/10) blend foaming under 100°C had the greatest open cell rate of 95.9% and high volume expansion ratio of 13.98, meanwhile, its water contact angle reduced to 62.5°. In addition, the fibroblast NIH/3T3 cells with live/dead cell fluorescence staining assay was utilized to examine the biocompatibility of PLA‐based scaffolds. Results indicated that the PLA/PBS/PEG scaffolds had better biocompatibility than PLA/PBS scaffolds. This work provides an easy and green approach for fabricating fully biodegradable PLA‐based scaffolds with high open cell rate and hydrophilicity in tissue engineering.
Tetrahydroquinazoline N‐oxide derivatives inhibit reproduction of tick‐borne and mosquito‐borne flaviviruses
Authors: Sedenkova Kseniya N. , Uvarova Victoria I. , Nazarova Anna A. , Peisikova Aleksandra V. , Khvatov Evgeny V. , Sukhorukov Maksim V. , Frolenko Vasilisa S. , Goryashchenko Alexander S. , Kholodilov Ivan S. , Grishin Yuri K. , Rybakov Viktor B. , Makenov Marat T. , Morozkin Evgeny S. , Karan Lyudmila S. , Kozlovskaya Liubov I. , Ishmukhametov Aydar A. , Osolodkin Dmitry I. , Averina Elena B. 
Published: May 2023

AbstractTick‐borne encephalitis virus (TBEV), yellow fever virus (YFV), and West Nile virus (WNV) are flaviviruses causing emerging arthropod‐borne infections of a great public health concern. Clinically approved drugs are not available to complement or replace the existing vaccines, which do not provide sufficient coverage. Thus, the discovery and characterization of new antiflaviviral chemotypes would advance studies in this field. In this study, a series of tetrahydroquinazoline N‐oxides was synthesized, and the antiviral activity of the compounds was assessed against TBEV, YFV, and WNV using the plaque reduction assay along with the cytotoxicity to the corresponding cell lines (porcine embryo kidney and Vero). Most of the studied compounds were active against TBEV (EC50 2 to 33 μM) and WNV (EC50 0.15 to 34 μM) and a few also demonstrated inhibitory activity against YFV (EC50 0.18 to 41 μM). To investigate the potential mechanism of action of the synthesized compounds, time‐of‐addition (TOA) experiments and virus yield reduction assays were performed for TBEV. The TOA studies suggested that the antiviral activity of the compounds should affect the early stages of the viral replication cycle after cell entry. Compounds with tetrahydroquinazoline N‐oxide scaffold show a broad spectrum of activity against flaviviruses and represent a promising chemotype for antiviral drug discovery.
Semi‐tensor product‐based algebra‐logic mixed representation and fault diagnosis for a class of gate networks
Authors: Liu Fengqiu , Shen Xun , Moschoyiannis Sotiris , Wu Yuhu 
Published: May 2023

AbstractThis article studies an algebra‐logic mixed representation of gate networks and its application to stuck‐at fault diagnosis. First, the gate network is characterized through a logic expression of disjoint sum‐of‐products, and the system structure of the gate network is described based on 2‐to‐1 multiplexers. Then, by resorting to the semi‐tensor product of matrices, a novel algebra‐logic mixed representation is proposed for the gate network through its logic expression and system structure. Furthermore, a novel stuck‐at fault diagnosis algorithm for the gate network is presented, where the stuck‐at fault testability of the gate network is equivalent to the solution existence of the system of linear equations. Finally, the fault diagnosis of the 4‐bit carry look‐ahead adder is carried out to demonstrate the effectiveness and feasibility of the proposed theoretical approach and algorithms.
Stereoselective Synthesis and Characterization of Indenone Azine‐Based Electron‐Accepting π‐Conjugated Systems
Authors: Takagi Shu I. , Hayakawa Masahiro , Fukazawa Aiko 
Published: May 2023

AbstractInvited for the cover of this issue is the group of Aiko Fukazawa at Kyoto University. The image depicts a N−N component replacing the one originally located between the exocyclic C=C bond of a cross‐conjugated dibenzofulvalene. Read the full text of the article at 10.1002/chem.202300181.
Acid‐Promoted Cyclization Reaction of the Guanine Base with 1,1,3,3‐Tetramethoxypropane: A Method for the Preparation of M1dG and its Derivatives
Authors: Sun Wen‐Wu , Xie Yi‐Bing , Deng Ting‐Ting , Huang Jie , Liu Ji‐Kai , Wu Bin 
Published: May 2023

AbstractDespite the importance of nucleosides and nucleotides for drug discovery, only a few practical methods to prepare tricyclic nucleosides have been reported. Here, we describe a synthetic strategy for late‐stage functionalization of nucleosides and nucleotides via chemo‐ and site‐selective acid‐promoted intermolecular cyclization. The nucleoside analogs with an additional ring were obtained in moderate‐to‐high yields, including some antiviral drugs (acyclovir, ganciclovir, and penciclovir) derivatives, endogenous fused ring nucleoside (M1dG) and its derivatives, and nucleotide derivatives. © 2023 Wiley Periodicals LLC.Basic Protocol 1: Synthesis of tricyclic acyclovir analogs (3a‐3c)Basic Protocol 2: Synthesis of tricyclic nucleosides M1dG (6) and M1G (9)Basic Protocol 3: Synthesis of tricyclic nucleotide (12)
High‐pressure Synthesis, Structure, IR Spectroscopy, and Theoretical Calculations of the New Silver Tetraborate Ag2B4O7 with a Unique Crystal Structure
Authors: Ziegler Raimund , Purtscher Felix R. S. , Hofer Thomas S. , Huppertz Hubert 
Published: May 2023

AbstractAg2B4O7 is synthesized at high‐pressure/high‐temperature conditions of 11 GPa and 1073 K in a multianvil device. It crystallizes in the monoclinic centrosymmetric space group P21/c (no. 14) with four formula units per unit cell (Z=4). The cell parameters are a=787.53(3), b=651.63(2), c=943.88(3) pm, β=107.911(2)°, and V=460.90(3) Å3. Ag2B4O7 crystallizes in a unique crystal structure that consists of complex anionic borate layers with Ag+ ions in between. Additionally, the silver cations show argentophilic interactions. The compound was analysed via single‐crystal and powder diffraction as well as infrared spectroscopy. Furthermore, theoretical calculations at HSEsol level were conducted.
Finally Stable and Homoleptic: Isolation and Characterization of {Cu[Fe(CO)5]2}+ Stabilized with Perfluoroalkoxyaluminate Anion, [Al(OC(CF3)3)4]−
Authors: Zhuravlev Vadim , Malinowski Przemysław J. 
Published: May 2023

AbstractDevelopments in the chemistry of weakly coordinating anions enabled isolation of numerous unique metal complexes with unusual ligands. An important example is the family of metal‐Fe(CO)5 complexes. In the current paper we present synthesis and thorough characterization of the first truly homoleptic {Cu[Fe(CO)5]2}+ cation obtained as a salt of weakly coordinating [Al(ORF)4]− (RF=C(CF3)3) anion. TGA/DSC/MS study show that its decomposition becomes noticeable only above 110 °C, thus it can be stored as powder in air‐free conditions for months. The crystal structure of {Cu[Fe(CO)5]2}+ shows strong asymmetry of the cation and very short Cu‐CO bonds in comparison to analogous {M[Fe(CO)5]2}+ where M=Ag or Au. Characterization is complemented with analysis of vibrational spectra and extensive DFT calculations which give insight into the energetics of Cu+‐Fe(CO)5 systems. Our results show that {Cu[Fe(CO)5]2}+ is homoleptic only as salt of [Al(ORF)4]−. Furthermore, in the presence of additional, even weakly basic ligands, the Cu+‐Fe(CO)5 bond strength decreases what may contribute to the complex's instability in liquid SO2 or in the presence of [SbF6]−. These conclusions point at the key role of selection of proper anion and solvent in stabilization of these types of complexes.
Multifaceted Behavior of 2‐Cyanobenzaldehyde and 2‐Acylbenzonitriles in the Synthesis of Isoindolinones, Phthalides and Related Heterocycles
Authors: Mousavi Mohammad Sadeq , Di Mola Antonia , Massa Antonio 
Published: May 2023

Abstract2‐Cyanobenzaldehye (also called 2‐formylbenzonitrile) and related 2‐acylbenzonitriles belong to a class of bifunctional aromatic compounds that emerged as useful starting materials in developing efficient cascade‐type reactions leading to different heterocyclic compounds. The variety of sometimes unpredictable mechanisms that rise from these structurally simple starting materials renders this class of compounds unique to afford, through divergent cascade reactions, heterocycles like isoindolinones, phthalides (also known with the name of isobenzofuranones), imidates, and in less extent isoindolin‐1‐imine, six‐ and seven‐membered heterocycles, porphyrins, also in asymmetric way exploiting different organocatalytic activation modes. To give a picture, this chemistry can be associated to Goldberg variations which stem from a common motive in a pressing and surprising way. In this Review, emphasis is also given to the synthetic methods for the access to substituted 2‐cyanobenzaldehydes and 2‐acylbenzonitriles which allowed to enlarge the scope of the described cascade reactions.
A numerical study on the effects of using combined flow fields and obstacles on the performance of proton exchange membrane fuel cells
Authors: Chen Yuan , Liu Xiaori , Rao Zhonghao 
Published: May 2023

AbstractThe flow field structure has an important influence on the comprehensive performance of the proton exchange membrane fuel cell (PEMFC). This research investigates the effects of combined flow fields on the distribution of species concentration, the pressure drop, and the overall performance of PEMFC based on the polarization curve and power consumption ratio (PCR). Obstacles are arranged in different areas to study the mass transfer of the gas inside the combined flow field. The results show that the combined serpentine flow field improves the concentration distribution of species and the performance of the cell is enhanced with the increase of the proportion of the single‐channel serpentine structure in the combined flow field, but the PCR is decreased. The energy efficiency conversion in the low voltage region is better when the obstacles are arranged in the entire flow field. Moreover, the vortex effect generated by the obstacles enhances the convection ability under the rib parallel to the inlet direction, while the transverse vortex and secondary flow perpendicular to the inlet direction are weakened by the flow field structure so that the mass transfer of gas is enhanced.
Newborns during the crisis: Evidence from the 1980s′ farm crisis
Authors: Yu Chan 
Published: May 2023

AbstractThe sudden and jumping interest rate in the early 1980s triggered a severe economic crisis in the US agriculture sector. To identify the effects of wealth losses on the health condition of cohorts born in the midst of the crisis, this paper constructs an instrumental variable for wealth by exploiting the geographic variation in crop production and the timing of the shock. This study finds that wealth losses generates long‐lasting health impacts for these newborns. A one percent wealth loss leads to an approximately 0.008 and 0.003 percentage point increase in the low and very low birth weight rates, respectively. In addition, cohorts growing up in areas of greater impacts have worse self‐reported health condition before age 17 than others. They also have more metabolic‐syndrome issues and smoke more regularly than other cohorts in adulthood. Lower expenditures on food and prenatal care might explain the negative health effects on cohorts born during the crisis. The study shows that households in areas with greater wealth losses have more declining expenditures on food at home and prenatal‐care doctor visits.
Patient‐reported outcomes in immunotherapy for head and neck cancer
Authors: Kirtane Kedar , Hoogland Aasha I. , Li Xiaoyin , Rodriguez Yvelise , Scheel Kelsey , Small Brent J. , Oswald Laura B. , Muzaffar Jameel , Kish Julie A. , Bonomi Marcelo , Bhateja Priyanka , Saba Nabil F. , Steuer Conor E. , Chung Christine H. , Jim Heather S. L. 
Published: May 2023

AbstractBackgroundData about patient‐reported outcomes (PROs) among patients with head and neck squamous cell carcinoma (HNSCC) treated with immune checkpoint inhibitors are sparse. Our exploratory study evaluated PROs in patients with HNSCC starting treatment with immune checkpoint inhibitor monotherapy or combination therapy with cetuximab.MethodsPatients were recruited prior to receipt of their first checkpoint inhibitor therapy infusion. Participants completed measures of checkpoint inhibitor toxicities and quality of life (QOL) at on‐treatment clinic visits.ResultsAmong patients treated with checkpoint inhibitor monotherapy (n = 48) or combination therapy (n = 38) toxicity increased over time (p < 0.05), while overall QOL improved from baseline to 12 weeks, with stable or declining QOL thereafter (p < 0.05). There were no group differences in change in toxicity index or QOL. Toxicity index scores were significantly higher in the combination group at 18–20 weeks and 6 months post‐initiation of immune checkpoint inhibitor (p < 0.05). There were no significant group differences at baseline, the 6–8 week (p = 0.13) or 3‐month (p = 0.09) evaluations. The combination group reported better emotional well‐being at baseline than the monotherapy group (p = 0.04), There were no other group differences QOL at baseline or later timepoints.ConclusionsDespite increasing patient‐reported toxicity, checkpoint inhibitor monotherapy and combination therapy were associated with similar transient improvements, then worsening, of QOL in patients with HNSCC.
Metastatic renal cell carcinoma to the thyroid with cervicothoracic venous tumor thrombosis
Authors: Hellums Ryan N. , Kovatch Kevin J. , Friscia Michael E. , Schwartz Tyler R. , Pellitteri Phillip K. 
Published: May 2023

AbstractIntroductionMetastatic renal cell carcinoma (RCC) represents 25%–42% of metastatic thyroid malignancies. Propensity for RCC to demonstrate intravascular extension to the inferior vena cava is well documented. We present an analogous phenomenon of intravascular extension to the internal jugular vein (IJV) from thyroid gland metastasis.MethodsA 69‐year‐old male presented with metastatic RCC of the right thyroid lobe. Imaging demonstrated tumor thrombosis of the ipsilateral IJV, extending inferiorly to the junction of the brachiocephalic, subclavian, and internal jugular veins within the mediastinum.ResultsSurgical excision required control of both the IJV in the neck and mediastinal venous great vessels via sternotomy, prior to subtotal thyroidectomy and venotomy for en bloc resection.ConclusionThis case report describes metastatic RCC to the thyroid gland with cervicothoracic venous tumor thrombosis successfully treated with subtotal thyroidectomy, sternotomy for venotomy and tumor thrombectomy, and preservation of IJV conduit.
Prognostic impact of kallikrein‐related peptidase transcript levels in prostate cancer
Authors: Lehto Timo‐Pekka K. , Kovanen Ruusu‐Maaria , Lintula Susanna , Malén Adrian , Stürenberg Carolin , Erickson Andrew , Pulkka Olli‐Pekka , Stenman Ulf‐Håkan , Diamandis Eleftherios P. , Rannikko Antti , Mirtti Tuomas , Koistinen Hannu 
Published: May 2023

AbstractWe aimed to study mRNA levels and prognostic impact of all 15 human kallikrein‐related peptidases (KLKs) and their targets, proteinase‐activated receptors (PARs), in surgically treated prostate cancer (PCa). Seventy‐nine patients with localized grade group 2‐4 PCas represented aggressive cases, based on metastatic progression during median follow‐up of 11 years. Eighty‐six patients with similar baseline characteristics, but no metastasis during follow‐up, were assigned as controls. Transcript counts were detected with nCounter technology. KLK12 protein expression was investigated with immunohistochemistry. The effects of KLK12 and KLK15 were studied in LNCaP cells using RNA interference. KLK3, ‐2, ‐4, ‐11, ‐15, ‐10 and ‐12 mRNA, in decreasing order, were expressed over limit of detection (LOD). The expression of KLK2, ‐3, ‐4 and ‐15 was decreased and KLK12 increased in aggressive cancers, compared to controls (P < .05). Low KLK2, ‐3 and ‐15 expression was associated with short metastasis‐free survival (P < .05) in Kaplan‐Meier analysis. PAR1 and ‐2 were expressed over LOD, and PAR1 expression was higher, and PAR2 lower, in aggressive cases than controls. Together, KLKs and PARs improved classification of metastatic and lethal disease over grade, pathological stage and prostate‐specific antigen combined, in random forest analyses. Strong KLK12 immunohistochemical staining was associated with short metastasis‐free and PCa‐specific survival in Kaplan‐Meier analysis (P < .05). Knock‐down of KLK15 reduced colony formation of LNCaP cells grown on Matrigel basement membrane preparation. These results support the involvement of several KLKs in PCa progression, highlighting, that they may serve as prognostic PCa biomarkers.
New insights on the catalytic center of proteins from peptidylprolyl isomerase group based on the FOD‐M model
Authors: Roterman Irena , Stapor Katarzyna , Konieczny Leszek 
Published: May 2023

AbstractGenerating the structure of the hydrophobic core is based on the orientation of hydrophobic residues towards the central part of the protein molecule with the simultaneous exposure of polar residues. Such a course of the protein folding process takes place with the active participation of the polar water environment. While the self‐assembly process leading to the formation of micelles concerns freely moving bi‐polar molecules, bipolar amino acids in polypeptide chain have limited mobility due to the covalent bonds. Therefore, proteins form a more or less perfect micelle‐like structure. The criterion is the hydrophobicity distribution, which to a greater or lesser extent reproduces the distribution expressed by the 3D Gaussian function on the protein body. The vast majority of proteins must ensure solubility, so a certain part of it—as it is expected—should reproduce the structuring of micelles. The biological activity of proteins is encoded in the part that does not reproduce the micelle‐like system. The location and quantitative assessment of the contribution of orderliness to disorder is of critical importance for the determination of biological activity. The form of maladjustment to the 3D Gauss function may be varied—hence the obtained high diversity of specific interactions with strictly defined molecules: ligands or substrates. The correctness of this interpretation was verified on the basis of the group of enzymes Peptidylprolyl isomerase—E.C.5.2.1.8. In proteins representing this class of enzymes, zones responsible for solubility—micelle‐like hydrophobicity system—the location and specificity of the incompatible part in which the specific activity of the enzyme is located and coded were identified. The present study showed that the enzymes of the discussed group show two different schemes of the structure of catalytic center (taking into account the status as defined by the fuzzy oil drop model).
Effect of Bacillus subtilis and Lactobacillus plantarum on solid‐state fermentation of soybean meal
Authors: Chen Qianqian , Liu Bo , Liu Guohong , Shi Huai , Wang Jieping 
Published: May 2023

AbstractBACKGROUNDAs feeding probiotics, Bacillus subtilis FJAT‐4842 and Lactobacillus plantarum FJAT‐13737 were employed to improve the nutritional value and reduce the risk of contamination in the solid‐state fermentation of soybean meal (SBM).RESULTSAfter fermentation with bacterium starters, the crude protein, free amino acid and lactic acid increased, with higher protease and cellulose activity. The addition of L. plantarum could increase the crude protein and lactic acid content by 50.1% and 94.9%, respectively. After fermentation, the contents of crude fiber and phytic acid decreased by 45.9% and 48.1%. Compared with control treatment, the addition of both B. subtilis FJAT‐4842 and L. plantarum FJAT‐13737 could effectively elevate the production of free amino acid and esters. Moreover, the addition of bacterium starter could prevent the production of mycotoxin and promote bacterial diversity of the fermented SBM. Especially, the addition of B. subtilis could reduce the relative content of Staphylococcus. After fermentation for 7 days, lactic acid bacteria including Pediococcus, Weissella and Lactobacillus became the main bacteria in the fermented SBM.CONCLUSIONThe addition of bacterium starter is of benefit with respect to improving the nutritional value and reducing the risk of contamination in the solid‐state fermentation of soybean. © 2023 Society of Chemical Industry.