bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring the Lewis Acidity and Reactivity of Neutral Pentacoordinate Dithienophospholes
Authors: Asok Nayanthara , Zondag Benjamen A. , Pradhan Ekadashi , Odagwe Mary , LeBlanc Jesse , Walsh Joshua C. , Bodwell Graham J. , Zeng Tao , Baumgartner Thomas
Published: March 2023

A series of luminescent, neutral pentacoordinate dithieno[3,2‐b:2’,3’‐d]phosphole compounds was synthesized by [4+1] cycloaddition of o‐quinones with the corresponding trivalent phospholes. The electronic and geometrical modification of the π‐conjugated scaffold implemented here impacts the aggregation behavior of the species in solution. It proved successful in generating species with improved Lewis acidity of the phosphorus center that was then leveraged for small‐molecule activation. Hydride abstraction from an external substrate involving the hypervalent species is followed by an intriguing P‐mediated umpolung from the hydride to a proton and supports the catalytic potential of this class of main‐group Lewis acids for organic chemistry. This study is a comprehensive investigation into various methods, including electronic, chemical, geometric modifications (and sometimes combinations of these approaches) to systematically improve the Lewis acidity of neutral and stable main‐group Lewis acids with practical value for a range of chemical transformations.
Overcoming Energy Transfer for the Metallophotoredox Catalyzed Decarboxylative Alkenylation between Alkylcarboxylic Acids and Enol Triflates
Authors: Pedersen Stephan K. , Clementson Sebastian , El‐Chami Kassem , Kristensen Jesper L. , Jessing Mikkel
Published: March 2023

Herein we report on the decarboxylative alkenylation between alkyl carboxylic acids and enol triflates. The reaction is mediated by a dual catalytic nickel and iridium system, operating under visible light irradiation. Two competing catalytic pathways, from the excited state iridium photocatalyst, are identified. One is energy transfer from the excited state, resulting in formation of an undesired enol ester. The desired pathway involves electron transfer, resulting in decarboxylation to ultimately give the target product. The use of a highly oxidizing iridium photocatalyst is essential to control the reactivity. A diverse array of enol triflates and alkyl carboxylic acids are investigated, providing both scope and limitations of the presented methodology.
“Catch‐Store‐Release” Strategy for the Stabilization of 4,4′‐Methylene Diphenyl Diisocyanate (4,4′‐MDI)
Authors: Dissanayake Asanka I. , Hollingsworth Thilini S. , Madarang Elizabeth , Hamilton Patrick N. , Ward Cassandra L. , Groysman Stanislav
Published: March 2023

4,4′‐Methylene diphenyl diisocyanate (MDI) is an industrially crucial compound, being one of the most utilized linkers in the polyurethane industry. However, its long‐term stability is limited due to dimerization to form insoluble uretdione. Herein we demonstrate an organometallic “catch‐store‐release” concept aiming at improving the long‐term chemical stability of MDI. Treatment of MDI with two equivalents of selected N‐heterocyclic carbenes (NHC) forms stable MDI−NHC adducts. Treatment of the adducts with CuCl forms metastable di‐CuI complexes that undergo decomposition to re‐form MDI (up to 85 %), along with Cu−NHC complexes. The yield of re‐formed MDI can be improved (up to 95 %) by the release of the NHC ligands in the form of thiourea; this prevents subsequent MDI dimerization/polymerization by the carbenes. Furthermore, the need to separate MDI from the reaction mixture can be eliminated by the direct reaction of MDI−NHC complexes with alcohols (as models for diols), that form dicarbamate (as a model for polyurethane) quantitatively.
The effectiveness of neoadjuvant chemoradiotherapy in oesophageal adenocarcinoma with presence of extracellular mucin, signet‐ring cells, and/or poorly cohesive cells
Authors: Valkema Maria J , Vos Anne‐Marie , van der Post Rachel S , Ooms Ariadne HAG , Oudijk Lindsey , Eyck Ben M , Lagarde Sjoerd M , Wijnhoven Bas PL , Klarenbeek Bastiaan R , Rosman Camiel , van Lanschot J Jan B , Doukas Michail
Published: March 2023

Oesophageal adenocarcinomas may show different histopathological patterns, including excessive acellular mucin pools, signet‐ring cells (SRCs), and poorly cohesive cells (PCCs). These components have been suggested to correlate with poor outcomes after neoadjuvant chemoradiotherapy (nCRT), which might influence patient management. However, these factors have not been studied independently of each other with adjustment for tumour differentiation grade (i.e. the presence of well‐formed glands), which is a possible confounder. We studied the pre‐ and post‐treatment presence of extracellular mucin, SRCs, and/or PCCs in relation to pathological response and prognosis after nCRT in patients with oesophageal or oesophagogastric junction adenocarcinoma. A total of 325 patients were retrospectively identified from institutional databases of two university hospitals. All patients were scheduled for ChemoRadiotherapy for Oesophageal cancer followed by Surgery Study (CROSS) nCRT and oesophagectomy between 2001 and 2019. Percentages of well‐formed glands, extracellular mucin, SRCs, and PCCs were scored in pre‐treatment biopsies and post‐treatment resection specimens. The association between histopathological factors (≥1 and >10%) and tumour regression grade 3–4 (i.e. >10% residual tumour), overall survival, and disease‐free survival (DFS) was evaluated, adjusted for tumour differentiation grade amongst other clinicopathological variables. In pre‐treatment biopsies, ≥1% extracellular mucin was present in 66 of 325 patients (20%); ≥1% SRCs in 43 of 325 (13%), and ≥1% PCCs in 126 of 325 (39%). We show that pre‐treatment histopathological factors were unrelated to tumour regression grade. Pre‐treatment presence of >10% PCCs was associated with lower DFS (hazard ratio [HR] 1.73, 95% CI 1.19–2.53). Patients with post‐treatment presence of ≥1% SRCs had higher risk of death (HR 1.81, 95% CI 1.10–2.99). In conclusion, pre‐treatment presence of extracellular mucin, SRCs, and/or PCCs is unrelated to pathological response. The presence of these factors should not be an argument to refrain from CROSS. At least 10% PCCs pre‐treatment and any SRCs post‐treatment, irrespective of the tumour differentiation grade, seem indicative of inferior prognosis, but require further validation in larger cohorts.
Understanding and controlling asthma in Latin America: A review of recent research informed by the SCAALA programme
Authors: Cooper Philip J. , Figueiredo Camila A. , Rodriguez Alejandro , dos Santos Leticia Marques , Ribeiro‐Silva Rita C. , Carneiro Valdirene Leao , Costa Gustavo , Magalhães Thiago , dos Santos de Jesus Talita , Rios Raimon , da Silva Hugo Bernardino F. , Costa Ryan , Chico Martha E. , Vaca Maritza , Alcantara‐Neves Neuza , Rodrigues Laura C , Cruz Alvaro A. , Barreto Mauricio L.
Published: March 2023

Asthma is an important health concern in Latin America (LA) where it is associated with variable prevalence and disease burden between countries. High prevalence and morbidity have been observed in some regions, particularly marginalized urban populations. Research over the past 10 years from LA has shown that childhood disease is primarily non‐atopic. The attenuation of atopy may be explained by enhanced immune regulation induced by intense exposures to environmental factors such as childhood infections and poor environmental conditions of the urban poor. Non‐atopic symptoms are associated with environmental and lifestyle factors including poor living conditions, respiratory infections, psychosocial stress, obesity, and a diet of highly processed foods. Ancestry (particularly African) and genetic factors increase asthma risk, and some of these factors may be specific to LA settings. Asthma in LA tends to be poorly controlled and depends on access to health care and medications. There is a need to improve management and access to medication through primary health care. Future research should consider the heterogeneity of asthma to identify relevant endotypes and underlying causes. The outcome of such research will need to focus on implementable strategies relevant to populations living in resource‐poor settings where the disease burden is greatest.
Phase 1b study of pan‐AKT inhibitor vevorisertib alone or with paclitaxel or fulvestrant in PIK3CA/AKT/PTEN‐mutated advanced solid tumors
Authors: Pant Shubham , Hamilton Erika , Ulahannan Susanna V. , Strauss James F. , Braiteh Fadi S. , Huang Mo , Liaw Danny Chih Hsun
Published: March 2023

Background

In this first‐in‐human phase 1b study (ClinicalTrials.gov identifier NCT02761694) of advanced solid tumors with PIK3CA/AKT/PTEN mutations, the authors investigated the safety and efficacy of the pan‐AKT inhibitor vevorisertib (MK‐4440; ARQ 751) as monotherapy or with paclitaxel or fulvestrant.

Methods

Patients with histologically confirmed, advanced or recurrent, PIK3CA/AKT/PTEN‐mutated solid tumors, measurable disease according to Response Evaluation Criteria in Solid Tumors, version 1.1, and an Eastern Cooperative Oncology Group performance status ≤1 received vevorisertib (dose range, 5–100 mg) alone or with paclitaxel 80 mg/m2 or fulvestrant 500 mg. The primary end point was safety and tolerability. Secondary end points included pharmacokinetics and the objective response rate according to Response Evaluation Criteria in Solid Tumors, version 1.1.

Results

Of 78 patients enrolled, 58 received vevorisertib monotherapy, 10 received vevorisertib plus paclitaxel, and nine received vevorisertib plus fulvestrant. Dose‐limiting toxicity occurred in three patients (vevorisertib monotherapy, n = 2 [grade 3 pruritic and maculopapular rashes]; vevorisertib plus paclitaxel, n = 1 [grade 1 asthenia]). Across doses, treatment‐related AEs occurred in 46 patients (79%) with vevorisertib monotherapy, in 10 patients (100%) with vevorisertib plus paclitaxel, and in nine patients (100%) with vevorisertib plus fulvestrant; and grade 3 treatment‐related AEs occurred in 13 (22%), 7 (70%), and 3 (33%) patients, respectively. No grade 4/5 treatment‐related AEs occurred. Maximum vevorisertib concentrations were reached 1–4 hours after dosing; the elimination half‐life ranged from 8.8 to 19.3 hours. The objective response rate was 5% with vevorisertib monotherapy (three partial responses), 20% with vevorisertib plus paclitaxel (two partial responses), and 0% with vevorisertib plus fulvestrant.

Conclusions

Vevorisertib alone or with paclitaxel or fulvestrant had a manageable safety profile, and vevorisertib alone or with paclitaxel had minimal to modest antitumor activity in this patient population with PIK3CA/AKT/PTEN‐mutated advanced solid tumors. Clinical trial registration: ClinicalTrials.gov, NCT02761694.
Synthesis of 1,2‐Propanediol by Electro‐reduction of Formaldehyde with Oxygen‐enriched Graphene
Authors: Wang Yinyin , Qin Lang , Cao Cong , Geng Zhigang , Zeng Jie , Bao Jun
Published: March 2023

The conversion of electrocatalytic small molecules into high value‐added chemicals is a green and sustainable path to reduce energy consumption in traditional industrial production paths. In order to explore the relationship between oxygen function groups in the catalysts and their catalysis behavior, we prepared graphene‐based catalysts with different oxygen densities for formaldehyde reduction reaction by adjusting the content of oxygen‐containing functional groups on the graphene surface. We found that oxygen‐rich graphene (oGO) exhibited the highest activity as well as selectivity for the electroreduction of formaldehyde to 1,2‐propanediol (1,2‐PDO). Compared with graphite sheets and reduced graphene (rGO), the oGO exhibit the highest 1,2‐PDO Faradaic efficiency (FE) of 27.4% with partial current density of 13.7 mA cm−2 at pH 7. In‐situ attenuated total reflection infrared spectroscopy (ATR‐IR) confirms that the increased content of oxygen‐containing groups on the catalyst surface promotes the adsorption and enrichment of ⋅H2CO, which in turn facilitates the coupling reaction to form 1,2‐PDO. This work provides a new vision for the catalyst design in the electrochemical conversion reaction from formaldehyde to 1,2‐PDO.
Transcriptome differential display of a drought‐tolerant early flowering spineless mutant of safflower (Carthamus tinctorius) and identification of candidate genes
Authors: Karami‐Moalem Samaneh , Ahmadikhah Asadollah , Nemati Zahra , Haghi Reza
Published: March 2023

One of the best candidates to face the increasing environmental stresses is safflower (Carthamus tinctorius L.) with natural tolerance to multiple abiotic stresses including drought. In the present study, transcriptome profile of a spineless drought‐tolerant mutant of safflower with early flowering was compared to its spiny wild type. In differential RNA‐Seq analyses more than 400 differentially expressed genes (DEGs) were identified in spineless drought‐tolerant mutant. The expression of 8 top DEGs, mostly related to the contrasting traits, was confirmed by real‐time quantitative reverse transcription PCR. Transcription factors (TFs) followed by protein kinases had the highest frequency among the identified DEGs. TF families involved in the regulation of cell cycle, development, and environmental responses were prevalent in DEGs of spineless drought‐tolerant mutant, including NAC, bHLH, MYB, HD‐ZIP, and ERF. Three Kyoto Encyclopedia of Genes and Genomes pathways with direct or indirect role in cell/tissue development and metabolic processes were enriched for DEGs. Our results suggest that phenotypic differences between the two contrasting genotypes can be governed via regulation of hormone signal transduction/or cell cycle and stress‐related pathways. Several candidate genes for spine formation, early flowering, and drought tolerance were introduced, important instances are ZHD8 and TBL21 (candidates for spininess), three novel transcripts, respectively, encoding a CCT type protein, a MADS‐box TF and a CCA1 (candidates for early flowering), and CAT2, ZAT10, and CAMTA (candidates for drought response). These findings facilitate the isolation of key genes controlling drought‐tolerance, spininess, and early flowering in safflower and can be applied for developing value‐added varieties through genome‐based breeding programs.
A dynamic capabilities perspective on implementing the Circular Transition Indicators: A case study of a multi‐national packaging company
Authors: Walker Anna M. , Simboli Alberto , Vermeulen Walter J. V. , Raggi Andrea
Published: March 2023

The use of life cycle‐based assessment has been defined a crucial microfoundation to implement circular business models from a dynamic capabilities perspective. Through a case study of a multi‐national packaging corporation in the plastics sector, the application of an industry‐developed circularity assessment, the Circular Transition Indicators (CTI), is analysed in two manufacturing locations (Italy and China). The aim is to identify how this life cycle‐based assessment can amplify the company's capability to sense, seize and reconfigure its resources. Data were collected from a company placement, interviews, and sustainability reports. The CTI mainly contributed to the sensing microfoundations concerning the company's life cycle‐based perspective and the use of environmental management tools. It also proved to complement existing life cycle‐based approaches because it does not identify sustainability impacts, but only captures material flows. Furthermore, the results showed how the CTI implementation benefitted from existing microfoundations, such as the strategic collaboration with knowledge partners and previously collected sustainability and process efficiency data. Finally, it was also discussed for which microfoundations the CTI results could be most useful: to improve internal resource management processes and to support external circularity pledges. This paper contributes an empirical example to connect dynamic capabilities with life cycle management literature in a circular economy context.
Efficient Electroreduction of Nitrate to Ammonia with CuPd Nanoalloy Catalysts
Authors: Song Zhimin , Qin Lang , Liu Yan , Zhong Yongzhi , Guo Qing , Geng Zhigang , Zeng Jie
Published: March 2023

The electroreduction of nitrate (NO3−) to valuable ammonia (NH3) is a green and appealing alternative to the Haber‐Bosch process. Nevertheless, this process suffers from low performance for NH3 due to the sluggish multi‐electron/proton‐involved steps. In this work, a CuPd nanoalloy catalyst was developed toward NO3− electroreduction at ambient conditions. By modulating the atomic ratio of Cu to Pd, the hydrogenation steps of NH3 synthesis during NO3− electroreduction can be effectively controlled. At −0.7 V versus reversible hydrogen electrode (vs. RHE), the optimized CuPd electrocatalysts achieved a Faradaic efficiency for NH3 of 95.5 %, which was 1.3 and 1.8 times higher than that of Cu and Pd, respectively. Notably, at −0.9 V vs. RHE, the CuPd electrocatalysts showed a high yield rate of 36.2 mg h−1 cm−2 for NH3 with a corresponding partial current density of −430.6 mA cm−2. Mechanism investigation revealed the enhanced performance originated from the synergistic catalytic cooperation between Cu and Pd sites. The H‐atoms adsorbed on the Pd sites prefer to transfer to adjacent nitrogen intermediates adsorbed on the Cu sites, thereby promoting the hydrogenation of intermediates and the formation of NH3.
Whole‐mitochondrial genomes of Nannizziopsis provide insights in evolution and detection
Authors: Powell Daniel , Schwessinger Benjamin , Frère Céline H.
Published: March 2023

Infectious fungal diseases can have devastating effects on wildlife health and a detailed understanding of the evolution of related emerging fungal pathogen along with the ability to detect them in the wild is considered indispensable for effective management strategies. Several fungi from the genera Nannizziopsis and Paranannizziopsis are emerging pathogens of reptiles and have been observed to cause disease in a wide range of taxa. Nannizziopsis barbatae has become a particularly important pathogen of Australian reptiles with an increasing number of herpetofauna being reported with cases of infection from across the country. Here, we present the mitochondrial genome sequences and phylogenetic analysis for seven species in this group of fungi uncovering new information on the evolutionary relationship of these emerging pathogens. From this analysis, we designed a species‐specific qPCR assay for the rapid detection of N. barbatae and demonstrate its application in a wild urban population of a dragon lizard.
Computational investigation of MnIr and FeIr electrocatalyst for nitrogen reduction reaction
Authors: Ma Pengfei , Li Chensi , Zhang Wei , Jia Meng , Song Wei
Published: March 2023

NH3 is not only an important component of agricultural and industrial production, but also an extremely promising energy carrier and storage intermediate. Currently, the Haber‐Bosch process used in industry for NH3 production has shortcomings such as high energy consumption and low output. The electrocatalytic nitrogen reduction reaction (NRR) can improve the route and conditions of NH3 synthesis through high‐efficient electrocatalyst, and realize the production mode of high efficiency and low energy consumption. Therefore, the design and synthesis of the NRR electrocatalysts with high catalytic performance are very important. Here, the first principles calculation based on density functional theory was used to form alloy catalysts by using Mn and Fe atoms instead of nine Ir atoms on the surface of Ir(100), and the electrocatalytic performance of the NRR was systematically studied. The results showed that N2 could be stably adsorbed on Mn9@Ir(100) and Fe9@Ir(100) in the side‐on configuration. The possible reaction pathways were analyzed and discussed, and the enzymatic pathway was determined to be the best. Through the simulation of the entire NRR process, it was found that the limit potential was only −0.659 and −0.647 V for Mn9@Ir(100) and Fe9@Ir(100). In addition, the electronic properties of Mn9@Ir(100) and Fe9@Ir(100) were analyzed utilizing charge density difference and density of states, and the reasons for their high activity were obtained. We hope this work can not only reduce the number of noble metals and develop highly active catalysts, but also provide theoretical support and guidance for the catalytic mechanism of alloy electrocatalysts.
Exploring the Impact of Ni Doping on Bagasse Biochar and Its Efficient Hydrogen Production via Assisted Water Electrolysis
Authors: Huang Kanzai , Chang Menglei , Zhang Jichuan , Luo Zhaoqi , Zhang Yuyuan , Zhao Kai , Wang Wen , Chen Dongchu
Published: March 2023

Heteroatom doping in carbon matrices has been widely used to prepare efficient carbonaceous electrocatalysts. Biochar‐assisted water electrolysis (BAWE) is a promising hydrogen production method that can efficiently utilize waste biomass. However, it is often limited by the slow anode biochar oxidation reaction (BOR). In addition, pure biochar typically lacks enough active catalytic sites; hence, its electrochemical reactivity is unsatisfactory. Herein, Ni is doped into bagasse biochar to improve its BOR. Its electrochemical properties and hydrogen production performance are measured using linear sweep voltammetry, electrochemical impedance spectroscopy, and chronopotentiometry. The reaction characteristics of the bagasse biochar are analyzed. The impact of its physiochemical properties on its oxidation process is discussed. Compared to the undoped biochar, the Ni‐doped biochar shows a larger specific surface area, a higher degree of graphitization, and stronger biochar oxidation reactivity (including a lower onset potential and larger electric current density), which significantly increase the electric current density and hydrogen production. This study provides a beneficial strategy for improving BAWE.
Ce‐Doped MoO3 Photocatalyst as an Environmental Purifier for Removal of Noxious Rhodamine B Organic Pollutant in Wastewater
Authors: Farid Hafiz Muhammad Tahir , Aman Salma , Ahmad Naseeb , Abo-Dief Hala M. , Alanazi Abdullah K. , Khosa Rabia Yasmin , Ansari Mohd Zahid , El-Bahy Zeinhom M.
Published: March 2023

Wastewater treatment and management have been hot topics for the past three decades. Water reuse can help to alleviate the problems of water shortage and wastewater treatment in practice. Water can be used for household uses once the organic contaminants are removed. In this research, bare MoO3 and Ce‐doped MoO3 are fabricated using a straightforward hydrothermal method for wastewater treatment. The different analytical techniques are utilized to study the physiochemical features of all the synthesized products. Rhodamine B (RhB) is reduced photocatalytically under exposure of visible light to ascertain the possible capacity. The photocatalytic results suggest that the photoreduction of RhB with 2% Ce‐doped MoO3 exhibits a greater photocatalytic activity of 91.83% than the pure and other doped materials. The kinetic study of 2% Ce‐doped MoO3 displays the greater rate constant of 0.0163 min−1 and a lower Rct value of 0.95 Ω. The research indicates that the doping approach is a very effective way to decrease the bandgap and boost RhB's photocatalytic reduction. Other environmental and water‐related problems can be solved using Ce‐doped MoO3's improved physical and structural characteristics.
Inhibiting effect of a composite formulation of kinetic and thermodynamic inhibitors for gas hydrate formation in high water cut oil–water emulsion
Authors: Liu Yu , Duan Jiateng , Xu Dianqiang , Chu Jiawei , Shen Shi , Zhao Jiafei , Jiang Lanlan
Published: March 2023

In oil and gas exploitation and transportation, it is essential to avoid hydrate blockage in the wellbores and pipelines. Using kinetic inhibitors in composite with thermodynamic inhibitors can reduce the operational expenditure for oil and gas pipelines under high water content conditions. The phase equilibria of pure water natural gas system, oil–water natural gas system, and oil–water monoethylene glycol (MEG) natural gas system were first investigated by experiments and combined with software predictions in this study. The results showed that both mineral oil and MEG shifted the phase equilibrium of the system to high‐pressure and low‐temperature directions. The oil phase increased the effective temperature range of the compounding inhibitor. Then the hydrate inhibition performance and natural gas hydrate generation characteristics of the composite formulation of Luvicap 55w and MEG in oil–water emulsions and natural gas mixtures were investigated. With the increased subcooling, the induction time decreased sharply, and the gas consumption increased. The induction time increased with increasing MEG concentration, which verified the synergistic effect of MEG in oil–water emulsion for Luvicap 55w. The hydrate generation characteristics did not change much with increasing Luvicap concentration at the same temperature. In contrast, the hydrate induction time rose from 142.8 to >3500 min as the MEG concentration increased from 10 to 20 wt%.
Prospects of low‐temperature solid sorbents in industrial CO₂ capture: A focus on biomass residues as precursor material
Authors: Querejeta Nausika , Gil María Victoria , Rubiera Fernando , Pevida Covadonga
Published: March 2023

Adsorption using bio‐based adsorbents has been pointed out as an economical and environmentally benign technology for CO₂ gas separation and storage. A bio‐based adsorbent can be fabricated from low‐cost worldwide available biomass feedstock and bio‐wastes from different industries (e.g., dairy manure, forestry, agriculture). As a result, it is a carbon rich material of hydrophobic nature, activated to gain high porosity development, and requires mild regeneration conditions. However, large‐scale deployment of bio‐based adsorption processes remains challenging. Our group has been intensively developing biomass‐based adsorbents in conjunction with the design of tailored CO₂ adsorption‐based cyclic processes for the envisioned application. Herein, key concepts on adsorption technology, biomass waste management, and different activation techniques for biomass‐based adsorbent precursors are discussed. This review addresses the most relevant studies in the literature, from lab experimentation on a milligram scale (volumetric and gravimetric tests) to dynamic tests in bench or large‐scale cyclic adsorption processes (i.e., pressure swing adsorption, temperature swing adsorption, vacuum swing adsorption). Therefore, the main target is to give a holistic view of the industrial applications where CO₂ separations with these materials are more suitable. Finally, concluding remarks and future perspectives of bio‐based adsorbents in carbon capture are presented. © 2023 The Authors. Greenhouse Gases: Science and Technology published by Society of Chemical Industry and John Wiley & Sons Ltd.
Correlations behind macrotrabecular‐massive and vessels encapsulating tumor cluster patterns in hepatocellular carcinoma
Authors: Sun Yong‐Wen , Chen Yu‐Peng , Kan Shi‐Ji , Liu Ya‐Dong , Ruan Zhi‐bing , Gao Bo
Published: March 2023

Macrotrabecular‐massive hepatocellular carcinoma (MTM‐HCC) is a subtype of HCC with a very poor prognosis and exhibits biological behaviors and clinical presentations that distinguish it from conventional HCC. Vessels encapsulating tumor clusters (VETC) is a unique pattern of vascular growth that is more common in patients with MTM‐HCC. This unique interaction between the angiogenic system and tumor cells is of general interest. Early diagnosis and appropriate treatment of HCC with MTM and VETC patterns help prevent early recurrence and improve prognosis. This review summarizes the existing findings for HCC with MTM and VETC patterns.
Hydrogen bonds ofOCNHmotif in rings in drugs: A molecular electrostatic potential analysis
Authors: Haritha Mambatta , Suresh Cherumuttathu H.
Published: March 2023

The OCNH unit is one of the most frequently encountered structural motifs in rings in drugs which serves dual role as the proton donor through NH bond and proton acceptor through the CO bond. Here, we predicted the HB strength (Eint) of OCNH motif with H2O for commonly observed 37 rings in drugs with DFT method M06L/6‐311++G(d,p). The HB strength is rationalized in terms of molecular electrostatic potential (MESP) topology parameters ΔVn(NH)and ΔVn(CO)which describe the relative electron deficient/rich nature of NH and CO, respectively, with respect to the reference formamide. TheEintof formamide is −10.0 kcal/mol whereas theEintof ring systems is in the range −8.6 to −12.7 kcal/mol—a minor increase/decrease compared to the formamide. The variations inEintare addressed using the MESP parameters ΔVn(NH)and ΔVn(CO)and proposed the hypothesis that a positive ΔVn(NH)enhances NH…Owinteraction while a negative ΔVn(CO)enhances the CO…Hwinteraction. The hypothesis is proved by expressingEintjointly as ΔVn(NH)and ΔVn(CO)and also verified for twenty FDA approved drugs. The predictedEintfor the drugs using ΔVn(NH)and ΔVn(CO)agreed well with the calculatedEint. The study confirms that even delicate variations in the electronic feature of a molecule can be quantified in terms of MESP parameters and they provide a priori prediction of the HB strength. The MESP topology analysis is recommended to understand the tunability of HB strength in drug motifs.
Adipose tissue and hematopoiesis: Friend or foe?
Authors: He Na , Liu Min , Wu Yue
Published: March 2023

Aim

Hematopoietic stem cells are the origin of all hematopoietic cells. They have the self‐renewal ability and can differentiate into various blood cells. In physiological state, most of the hematopoietic stem cells are dormant, and only a few cells proliferate to maintain hematopoietic homeostasis.

Methods

This precise steady‐state maintenance is regulated by complex mechanisms. Bone marrow adipocytes make up half of all cells in the bone marrow cavity, a feature that has attracted the attention of researchers from multiple fields. The adipocyte density within marrow increases during aging and obesity.

Results

Recent studies have shown that bone marrow adipocytes play important roles in regulating hematopoiesis, but the effects of bone marrow adipocytes on hematopoiesis are often conflicting. Bone marrow adipocytes, participating in the formation of bone marrow hematopoietic microenvironment, influence hematopoiesis positively or negatively. In addition, other adipose tissue, especially white adipose tissue, also regulates hematopoiesis.

Conclusion

In this review, we describe the role of adipose tissue in hematological malignancies, which may be useful for understanding hematopoiesis and the pathogenesis of related diseases.
The effectiveness and mechanical properties of chemotherapy‐impregnated cement in Ewing sarcoma
Authors: Goldin Amanda N. , Healey Robert M.
Published: March 2023

Bone cement is often used in the surgical treatment of Ewing sarcoma (ES). Chemotherapy‐impregnated cement (CIC) has never been tested in slowing ES growth. The purpose of the study is to determine if CIC can decrease cell proliferation, and to assess changes in the mechanical qualities of the cement. Chemotherapeutic agents including doxorubicin, cisplatin, etoposide, and SF2523 were mixed with bone cement. ES cells were plated and exposed to cell growth media that had contained CIC or regular bone cement (RBC) as a control, and cell proliferation assays were performed daily for 3 days. Mechanical testing on RBC and CIC was also performed. There was a significant decrease (p < 0.001) in cell proliferation among all cells treated with CIC compared to cells treated with RBC by 48 h postexposure. Additionally, there was a synergistic effectiveness of the CIC noted when multiple antineoplastic agents were combined. Three‐point bending tests did not reveal substantial reductions in tolerated maximum bending load and maximal displacement at maximal bending load between CIC and RBC. Statement of Clinical Significance: CIC does appear to be effective at decreasing cell growth and does not appear to substantially alter the mechanical properties of the cement.
Challenging the assumption of uniformity in patellar tendon structure: Regional patellar tendon morphology and mechanical properties in vivo
Authors: Ito Naoaki , Scattone Silva Rodrigo , Sigurðsson Haraldur B. , Cortes Daniel H. , Silbernagel Karin Grävare
Published: March 2023

Patellar tendons are assumed to be uniform in morphology and mechanical properties despite a higher prevalence of tendinopathies observed in the medial region. The purpose of this study was to compare the thickness, length, viscosity, and shear modulus of the medial, central, and lateral regions of healthy patellar tendons of young males and females in vivo. B‐mode ultrasound and continuous shear wave elastography were performed on 35 patellar tendons (17 females, 18 males) over three regions of interest. A linear mixed‐effects model (α = 0.05) was used to determine differences between the three regions and sexes followed by pairwise comparisons for significant findings. The lateral region (mean [95% confidence interval] = 0.34 [0.31–0.37] cm) was thinner compared with the medial (0.41 [0.39–0.44] cm,p < 0.001), and central (0.41 [0.39–0.44] cm,p < 0.001) regions regardless of sex. Viscosity was lower in the lateral (19.8 [16.9–22.7] Pa‐s) versus medial region (27.4 [24.7–30.2] Pa‐s,p = 0.001). Length had a region‐by‐sex interaction (p = 0.003) characterized by a longer lateral (4.83 [4.54–5.13] cm) versus medial (4.42 [4.12–4.72] cm) region in males (p < 0.001), but not females (p = 0.992). Shear modulus was uniform between regions and sexes. The thinner, and less viscous lateral patellar tendon may reflect the lower load the tendon experiences explaining the differences in regional prevalence of developing tendon pathology. Statement of Clinical Significance: Healthy patellar tendons are not uniform in morphology or mechanical properties. Considering regional tendon properties may help guide targeted interventions for patellar tendon pathologies.
Reduced angiogenesis and delayed endochondral ossification in CD163−/− mice highlights a role of M2 macrophages during bone fracture repair
Authors: Ren Youliang , Zhang Shiyang , Weeks Jason , Moreno Javier Rangel , He Bin , Xue Thomas , Rainbolt Joshua , Morita Yugo , Shu Ye , Liu Yuting , Kates Stephen L. , Schwarz Edward M. , Xie Chao
Published: March 2023

While recent studies showed that macrophages are critical for bone fracture healing, and lack of M2 macrophages have been implicated in models of delayed union, functional roles for specific M2 receptors have yet to be defined. Moreover, the M2 scavenger receptor CD163 has been identified as a target to inhibit sepsis following implant‐associated osteomyelitis, but potential adverse effects on bone healing during blockage therapy have yet to be explored. Thus, we investigated fracture healing in C57BL/6 versus CD163−/− mice using a well‐established closed, stabilized, mid‐diaphyseal femur fracture model. While gross fracture healing in CD163−/− mice was similar to that of C57BL/6, plain radiographs revealed persistent fracture gaps in the mutant mice on Day 14, which resolved by Day 21. Consistently, 3D vascular micro‐CT demonstrated delayed union on Day 21, with reduced bone volume (74%, 61%, and 49%) and vasculature (40%, 40%, and 18%) compared to C57BL/6 on Days 10, 14, and 21 postfracture, respectively (p < 0.01). Histology confirmed large amounts of persistent cartilage in CD163−/− versus C57BL/6 fracture callus on Days 7 and 10 that resolves over time, and immunohistochemistry demonstrated deficiencies in CD206+ M2 macrophages. Torsion testing of the fractures confirmed the delayed early union in CD163−/− femurs, which display decreased yield torque on Day 21, and a decreased rigidity with a commensurate increase in rotation at yield on Day 28 (p < 0.01). Collectively, these results demonstrate that CD163 is required for normal angiogenesis, callus formation, and bone remodeling during fracture healing, and raise potential concerns about CD163 blockade therapy.
Adjuvant radiotherapy after salvage surgery for melanoma recurrence in a node field following a previous lymph node dissection
Authors: Holtkamp Lodewijka H. J. , Lo Serigne N. , Thompson John F. , Spillane Andrew J. , Stretch Jonathan R. , Saw Robyn P. M. , Shannon Kerwin F. , Nieweg Omgo E. , Hong Angela M.
Published: March 2023

Background and Objectives

Adjuvant radiotherapy (RT) can be given to melanoma patients following salvage surgery for node field recurrence after a previous regional node dissection, but the value of this treatment strategy is poorly documented. This study evaluated long‐term node field control and survival of patients treated in this way in an era before effective adjuvant systemic therapy became available.

Methods

Data for 76 patients treated between 1990 and 2011 were extracted from an institutional database. Baseline patient characteristics, treatment details and oncological outcomes were analysed.

Results

Adjuvant RT with conventional fractionation (median dose 48 Gy in 20 fractions) was given to 43 patients (57%) and hypofractionated RT (median dose 33 Gy in 6 fractions) to 33 patients (43%). The 5‐year node field control rate was 70%, 5‐year recurrence‐free survival 17%, 5‐year melanoma‐specific survival 26% and 5‐year overall survival 25%.

Conclusions

Salvage surgery with adjuvant RT achieved node field control in 70% of melanoma patients with node field recurrence following a prior node dissection. However, disease progression at distant sites was common and survival outcomes were poor. Prospective data will be required to assess outcomes for contemporary combinations of surgery, adjuvant RT and systemic therapy.
Simultaneous Dual‐Color Amplified Spontaneous Emission and Lasing from Colloidal Quantum Well Gain Media in their Own Layered Waveguide and Cavity
Authors: Isik Ahmet Tarik , Shabani Farzan , Isik Furkan , Kumar Satish , Delikanli Savas , Demir Hilmi Volkan
Published: March 2023

Micro/nanoscale semiconductor multicolor lasers offer great potential for enhanced‐performance photonic circuits. Colloidal quantum wells (CQWs) are excellent candidates as active materials for these platforms owing to their superior properties including suppressed Auger recombination and large absorption cross‐section. In this work, multicolor optical gain and lasing from the heterostructures of CQWs as the gain media in their own all‐solution processed optical cavity are proposed and demonstrated for the first time. Here, using a simple waveguide slab consisting of the thin films of green‐emitting CdSeS/Cd0.1Zn0.9S core/hot‐injection‐shell grown CQWs and red‐emitting CdSe/CdS@CdZnS core/crown@shell CQWs, a transparent low refractive index colloidal spacing layer of silica nanoparticles (NPs) is devised that critically suppresses otherwise detrimental nonradiative energy transfer between the green and red‐emitting CQWs. This multilayer configuration is key to enabling simultaneous amplified spontaneous emission behavior in two colors with low threshold levels. This layered architecture is further adapted to a whispering‐gallery‐mode cavity by fabricating a microdisk pattern directly out of these CQWs‐NPs‐CQWs colloids. The resulting device exhibits dual‐color multimode lasing both at 569 and 648 nm at the same time. This unique multicolor lasing layered architecture holds great promise for on‐chip photonic applications such as dual‐color biological imaging.
Stability analysis and approximate solution of interval mathematical model for the COVID‐19 pandemic
Authors: Karunakar Perumandla , Reddy K. Shiva , Chakraverty Snehashish
Published: March 2023

In this paper, an interval solution has been constructed for the system of differential equations (SDEs) governing the COVID‐19 pandemic with uncertain parameters, namely, interval. The imposition of lockdown on infective has been considered as an interval parameter. As a result, the complete system of first‐order differential equations is transformed into interval form. The resulting interval system of differential equations (ISDEs) has been solved with help of the parametric concept and the Runge–Kutta method of order 4. Obtained results are compared with existing crisp results, and they are found to be in good agreement.
Convolutional neural network‐based model observer for signal known statistically task in breast tomosynthesis images
Authors: Jang Hanjoo , Baek Jongduk
Published: March 2023

Background

Since human observer studies are resource‐intensive, mathematical model observers are frequently used to assess task‐based image quality. The most common implementation of these model observers assume that the signal information is exactly known. However, these tasks cannot thoroughly represent situations where the signal information is not exactly known in terms of size and shape.

Purpose

Considering the limitations of the tasks for which signal information is exactly known, we proposed a convolutional neural network (CNN)‐based model observer for signal known statistically (SKS) and background known statistically (BKS) detection tasks in breast tomosynthesis images.

Methods

A wide parameter search was conducted from six different acquisition angles (i.e., 10°, 20°, 30°, 40°, 50°, and 60°) within the same dose level (i.e., 2.3 mGy) under two separate acquisition schemes: (1) constant total number of projections, and (2) constant angular separation between projections. Two different types of signals: spherical (i.e., SKE tasks) and spiculated (i.e., SKS tasks) were used. The detection performance of the CNN‐based model observer was compared with that of the Hotelling observer (HO) instead of the IO. Pixel‐wise gradient‐weighted class activation mapping (pGrad‐CAM) map was extracted from each reconstructed tomosynthesis image to provide an intuitive understanding of the trained CNN‐based model observer.

Results

The CNN‐based model observer achieved a higher detection performance compared to that of the HO for all tasks. Moreover, the improvement in its detection performance was greater for SKS tasks compared to that for SKE tasks. These results demonstrated that the addition of nonlinearity improved the detection performance owing to the variation of the background and signal. Interestingly, the pGrad‐CAM results effectively localized the class‐specific discriminative region, further supporting the quantitative evaluation results of the CNN‐based model observer. In addition, we verified that the CNN‐based model observer required fewer images to achieve the detection performance of the HO.

Conclusions

In this work, we proposed a CNN‐based model observer for SKS and BKS detection tasks in breast tomosynthesis images. Throughout the study, we demonstrated that the detection performance of the proposed CNN‐based model observer was superior to that of the HO.
Investigating a deep breathing intervention to promote mental health in P‐12 schools
Authors: Robertson Adrianne , Mason E. C. M. , Placeres Vanessa , Carter Hannah
Published: March 2023

Mental health factors can impact student academic performance and success. Student mental health concerns such as depression and anxiety and are a growing concern within P‐12 school systems. The dual pandemics of COVID‐19 and racial injustice have increased concerns about student mental health and exacerbated existing traumas particularly for students from marginalized populations. Trauma‐informed interventions that promote mental health in schools may be useful. Researchers utilized Consensual Qualitative Research to identify student mental health needs and outcomes for the implementation a deep breathing intervention in several schools in a large metropolitan city. The reasons for implementation, anticipated outcomes, reactions to intervention, perception of impact, and related personal experiences, as well as implications for practice and research, are all discussed.
Hamilton's principle with phase changes and conservation principles for moist potential vorticity
Authors: Kooloth Parvathi , Smith Leslie M. , Stechmann Samuel N.
Published: March 2023

Many definitions of moist potential vorticity (PV) have been proposed to extend the dry theory of Ertel PV. None of the moist PV definitions seem to have all of the desirable properties of the dry Ertel PV. For instance, dry PV is not only a globally conserved quantity, but also a material invariant that is conserved along fluid parcel trajectories. Therefore, an open question remains: Is there a moist PV that is a material invariant, if clouds and phase changes of water are present? In prior studies, definitions of moist PV have been proposed based on physical and mathematical intuition. Here, a systematic approach is used. In particular, a particle relabeling symmetry is devised for a moist atmosphere and then Noether's theorem is employed to arrive at the associated conservation laws for a moist PV. A priori, it is not clear whether this systematic approach will be viable, since it relies on variational derivatives in Hamilton's principle, and phase changes introduce singularities that could potentially prevent derivatives at the cloud edge. However, it is shown that the energy and the Lagrangian density are sufficiently smooth to allow variational derivatives, in a moist Boussinesq system with reversible phase transitions between water vapor and liquid cloud water. From the particle relabeling symmetry, a moist Kelvin circulation theorem is found, along with a moist PV conservation law that applies not for each individual parcel but for parcel‐integrated PV, integrated over certain local volumes.
Adsorption of Pb2+ and Cd2+ on the l‐cysteine‐functionalized graphene oxide/chitosan/polyvinyl alcohol hydrogel: Kinetic, isotherm, and thermodynamic study
Authors: Lemma Leta , Kiflie Zebene , Kassahun Shimelis K.
Published: March 2023

In this study, polyvinyl alcohol‐chitosan‐cysteine‐functionalized graphene oxide (PCCFG) hydrogel was synthesized from l‐cysteine‐functionalized graphene oxide (CFG), chitosan (CS), and polyvinyl alcohol (PVA). The hydrogel was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy and employed for removing lead ion (Pb2+) and cadmium ion (Cd2+) from aqueous solution. The effects of initial metal ion concentration, hydrogel dose, pH, time, and temperature were studied. The experimental data were well described by a pseudo‐second‐order kinetic model and Langmuir isotherm with maximum adsorption capacities of 250 and 192 mg g−1 at 25°C for Pb2+ and Cd2+, respectively. The adsorption capacity of the PCCFG hydrogel increased with an increase in temperature. The value of ∆G° was negative, which shows the spontaneity of the reaction (electron exchange or ion exchange) between the metal ion and electron‐rich atoms (–N, –S, –O). The positive ∆H° shows that the adsorption reaction consumes energy and the positive ∆S° shows the strong affinity of PCCFG toward the Pb2+ and Cd2+ ions. Pb2+ had better affinity and less spontaneity than Cd2+. The results show that the coexistence of Pb2+, Cd2+, and Cu2+ in the solution inhibits the adsorption capacity of PCCFG.