bluuebunny/crossref_metadata_2025 huggingface dataset:
Poverty reduction through water interventions: A review of approaches in sub‐Saharan Africa and South Asia
Authors: Ahmed Zeeshan , Gui Dongwei , Qi Zhiming , Liu Yi
Published: February 2022

Water is a key factor in attaining the Sustainable Development Goals (SDGs) of poverty elimination and hunger eradication. The regions of sub‐Saharan Africa (SSA) and South Asia (SA) are stricken with absolute poverty, with 70% of the world's poor. These regions are mainly dependent on agriculture for their livelihood. Diverse rural livelihoods in SSA and SA demand water interventions with more fruitful and effective outcomes in terms of poverty reduction. Existing water resources are not yet fully exploited in SSA and SA as these regions have a significant potential of 43 and 169 million ha, respectively, for irrigated agriculture through various water interventions. Various water interventions to alleviate poverty through better agricultural productivity across SSA and SA have been identified in this study. Major water intervention options identified include actions to: improve rain water management in rain‐fed agriculture, facilitate community‐based small‐scale irrigation schemes, development and management of groundwater irrigation, interventions to upgrade and modernize existing irrigation systems, facilitate and improve livestock production and promote multiple uses of water. Investment in these water interventions will certainly help to break the poverty trap across diverse rural communities of SSA and SA.
Vertex‐regular 1‐factorizations in infinite graphs
Authors: Costa Simone , Traetta Tommaso
Published: February 2022

The existence of 1‐factorizations of an infinite complete equipartite graph (with parts of size ) admitting a vertex‐regular automorphism group is known only when and is countable (i.e., for countable complete graphs) and, in addition, is a finitely generated abelian group of order . In this paper, we show that a vertex‐regular 1‐factorization of under the group exists if and only if has a subgroup of order whose index in is . Furthermore, we provide a sufficient condition for an infinite Cayley graph to have a regular 1‐factorization. Finally, we construct 1‐factorizations that contain a given subfactorization, both having a vertex‐regular automorphism group.
Latent class analysis of loneliness and connectedness in US young adults during COVID‐19
Authors: Schmidt Renae D. , Feaster Daniel J. , Horigian Viviana E. , Lee Richard M.
Published: February 2022

Objective

The coronavirus disease 2019 (COVID‐19) pandemic in the United States has exacerbated a number of mental health conditions and problems related to prolonged social isolation. While COVID‐19 has led to greater loneliness and a lack of social connectedness, little is known about who are the most affected and how they are impacted. Therefore, we performed a Latent Class Analysis using items from two scales – the UCLA Loneliness Scale and the Social Connectedness Scale – to characterize different experiences of loneliness and connectedness, examine their relationship with mental health and substance use symptoms, including depression, anxiety, drinking, and drug use.

Methods

Data were drawn from an anonymous one‐time online survey examining the mental health of 1008 young adults (18–35 years old) during COVID‐19. A latent class analysis (LCA) was conducted to observe and identify classes based on responses to loneliness and connectedness scale items, and to examine the existence of subgroups among this young adult population.

Results

We identified a 4‐class model of loneliness and connectedness: (1) Lonely and Disconnected – highest probabilities in items of loneliness and disconnectedness, (2) Moderately Lonely and Disconnected – adaptive levels of some isolation and disconnection during COVID‐19, (3) Ambivalent Feelings – displaying negative responses in particular to negatively‐worded items while simultaneously affirming positively worded items, and (4) Connected and Not Lonely – lowest probabilities in items of loneliness and disconnectedness.

Conclusion

Key findings include (1) the delineation of classes by levels of loneliness and connectedness showcasing differential mental health and substance use symptoms, (2) the utility of item‐level evaluation with LCA in determining specific classes of people in need of outreach and intervention, and (3) the promise of social connection to bolster resilience in young adults.
Single‐level cervical disc arthroplasty in the spine with reversible kyphosis: A finite element study
Authors: Hu Xu , Jiang Majiao , Hong Ying , Rong Xin , Huang Kangkang , Liu Hao , Pu Dan , Wang Beiyu
Published: February 2022

Background

Our previous studies found the single‐level cervical disc arthroplasty (CDA) might be a feasible treatment for the patients with reversible kyphosis (RK). Theoretically, the change of cervical alignment from lordosis to RK comes with the biomechanical alteration of prostheses and cervical spine. However, the biomechanical data of CDA in the spine with RK have not been reported. This study aimed at establishing finite element (FE) models to (1) explore the effects of RK on the biomechanics of artificial cervical disc; (2) investigate the biomechanical differences of single‐level anterior cervical discectomy and fusion (ACDF) and CDA in the cervical spine with RK.

Methods

The FE models of the cervical spine with lordosis and RK were constructed, then three single‐level surgical models were developed: (1) RK + ACDF; (2) RK + CDA; (3) lordosis + CDA. A 73.6‐N follower load combined with 1 N·m moment was applied at the C2 vertebra to produce cervical motion.

Results

At the surgical level, “lordosis + CDA” had the greatest ROM (except for flexion) while “RK + ACDF” had the minimum ROM. However, at adjacent levels, the ROM of “RK + ACDF” increased by 4.05% to 38.04% in comparison to “RK + CDA.” “RK + ACDF” had the greatest prosthesis interface stress, while the maximum prosthesis interface stress of “RK + CDA” was at least 2.15 times higher than “lordosis + CDA.” Similarly, “RK + ACDF” had the greatest intradiscal pressure (IDP) at adjacent levels, while the IDP of “RK + CDA” was 1.6 to 6.7 times higher than “lordosis + CDA.” At the surgical level, “RK + CDA” had the greatest facet joint stress (except for extension), which was 1.9 to 11.2 times higher than “lordosis + CDA.” At the adjacent levels, “RK + CDA” had the greatest facet joint stress (except for extension), followed by “RK + ACDF” and “lordosis + CDA” in descending order.

Conclusions

RK significantly changed the biomechanics of CDA, which is demonstrated by the decreased ROM and the significantly increased prosthesis interface stress, IDP, and facet joint stress in the “RK + CDA” model. Compared with ACDF, CDA overall exhibited a better biomechanical performance in the cervical spine with RK, with the increased ROM of surgical level and facet joint stress and the decreased ROM of adjacent levels, prosthesis interface stress, and IDP.
Anatomical and audiological considerations in branchiootorenal syndrome: A systematic review
Authors: Biggs Kirsty , Crundwell Gemma , Metcalfe Christopher , Muzaffar Jameel , Monksfield Peter , Bance Manohar
Published: February 2022

Objective

Establish anatomical considerations, audiological outcomes, and optimal management in patients with branchiootic/branchiootorenal syndrome (BO/BOR).

Methods

Databases reviewed: Medline, Pubmed, Embase, Web of Science, Cochrane Collection, and ClinicalTrials.gov. Clinical or radiological studies of patients with BOR syndrome describing either the audiological profile or anatomical changes were included. Articles in which BOR syndrome was associated with other syndromes, and those that were focused only on general and genetic aspects of BOR syndrome were excluded. Articles were assessed using Oxford Centre for Evidence‐Based Medicine (OCEBM) grading system and the Brazzelli risk of bias tool for nonrandomized studies.

Results

Searches identified 379 articles. Of these, 64 studies met the inclusion criteria, reporting outcomes in 482 patients from at least 95 families. In 308 patients, hearing loss was categorized as sensorineural (29%), conductive (20%), and mixed (51%). Hearing outcomes were variable in terms of onset, pattern, and severity; ranging from mild to profound deafness. One hundred sixty‐nine patients presented with inner ear anomalies, 145 had middle, and 151 had external ear abnormalities. In 44 studies, 58 ear operations were described. Mixed outcomes were reported in patients managed with hearing aids or middle ear surgery; however, successful cochlear implantation was described in all five cases.

Conclusion

The anatomical and audiological profiles of patients with BO/BOR are variable. A range of surgical procedures were described, however lacked objective outcome measures. Given the range of anatomical variants, management decisions should be made on an individual basis including full audiological and radiological assessment.

Level of evidence

NA.
Salt spray corrosion behavior and electrochemical performance of Al and Ti reinforced Ni60 coating by laser cladding
Authors: Chao Zhang , Dejun Kong
Published: February 2022

Ni60 coatings with the additions of Al and Ti were prepared on S355 steel by laser cladding. The microstructure and phases of obtained coatings were analyzed using an ultra‐depth of field microscope and X‐ray diffraction, respectively. The effects of Al and Ti additions on the salt spray corrosion and electrochemical performances were investigated using a salt spray corrosion chamber and electrochemical workstation, and the corrosion mechanism was also discussed by the models of defect reactions and pitting corrosion. The results show that the crystal microstructure of Ni60 coatings with the Al and Ti additions is changed from dendritic to massive and granular. After the neutral salt spray test, the corrosion forms of Ni60, Ni60–Al, and Ni60–Al–Ti coatings are mainly pitting and intergranular corrosion in which the Ni60–Al–Ti coating exhibits the highest anti‐corrosion performance. The improvement of electrochemical performance for the Ni60–Al–Ti coating is attributed to the high compact structure and passive film, which provides fewer oxygen vacancies in the corrosion process due to the additions of Al and Ti.
Surface Adaptable and Adhesion Controllable Dry Adhesive with Shape Memory Polymer
Authors: Lee Sung Ho , Song Hyun Woo , Park Han Jun , Kwak Moon Kyu
Published: February 2022

Gecko feet consist of numerous micro/nano hierarchical hairs and exhibit a high adhesion onto various surfaces by van der Waals forces. The gecko, despite its mighty adhesion, can travel efficiently with a rapid adhesion switching due to the end of the hairs on the gecko feet are slanted in one direction. Herein, a shape memory polymer (SMP)‐based switchable dry adhesive (SSA), inspired by gecko feet, having tremendous surface adaptability and adhesion switching capability, is reported. The SSA shows not only high adhesion to the various surfaces (≈332.8 kPa) but also easy detachment (nearly 3.73 kPa) due to the characteristic of SMP, which can reversibly recover from a deformed shape to its initial shape. On the basis of the novel adhesion switching property, it is suggested the SSA‐applied advanced glass transfer system can lead to feasible application. This experiment confirms that an ultrathin and light glass film is transferred easily and sustainably, and it is believed that the SSA may be a breakthrough and a powerful alternative for not only conventional dry adhesives but also the next‐level transfer systems.
Deletion of arylamine N‐acetyltransferase 1 in MDA‐MB‐231 human breast cancer cells reduces primary and secondary tumor growth in vivo with no significant effects on metastasis
Authors: Doll Mark A. , Ray Andrew R. , Salazar‐González Raúl A. , Shah Parag P. , Vega Alexis A. , Sears Sophia M. , Krueger Austin M. , Hong Kyung U. , Beverly Levi J. , Hein David W.
Published: February 2022

Arylamine N‐acetyltransferase 1 (NAT1) is frequently upregulated in breast cancer. Previous studies showed that inhibition or depletion of NAT1 in breast cancer cells diminishes anchorage‐independent growth in culture, suggesting that NAT1 contributes to breast cancer growth and metastasis. To further investigate the contribution of NAT1 to growth and cell invasive/migratory behavior, we subjected parental and NAT1 knockout (KO) breast cancer cell lines (MDA‐MB‐231, MCF‐7, and ZR‐75‐1) to multiple assays. The rate of cell growth in suspension was not consistently decreased in NAT1 KO cells across the cell lines tested. Similarly, cell migration and invasion assays failed to produce reproducible differences between the parental and NAT1 KO cells. To overcome the limitations of in vitro assays, we tested parental and NAT1 KO cells in vivo in a xenograft model by injecting cells into the flank of immunocompromised mice. NAT1 KO MDA‐MB‐231 cells produced primary tumors smaller than those formed by parental cells, which was contributed by an increased rate of apoptosis in KO cells. The frequency of lung metastasis, however, was not altered in NAT1 KO cells. When the primary tumors of the parental and NAT1 KO cells were allowed to grow to a pre‐determined size or delivered directly via tail vein, the number and size of metastatic foci in the lung did not differ between the parental and NAT1 KO cells. In conclusion, NAT1 contributes to primary and secondary tumor growth in vivo in MDA‐MB‐231 breast cancer cells but does not appear to affect its metastatic potential.
Capture of Spawning Brook Trout by Electrofishing Does Not Impair Embryo Survival
Authors: Howell Bradley E. , Stewart Erin M. C. , Frasca Vince R. , Wilson Chris C. , Raby Graham D.
Published: February 2022

Electrofishing is widely used to capture fish in freshwater systems. Fisheries assessment and fish culture activities that occur during spawning do so in the absence of a meaningful base of evidence about the potential effects of electrofishing on fish reproduction. In this laboratory experiment, we assessed whether electrofishing adult Brook Trout Salvelinus fontinalis affected the survival of their embryos. We used two genetically distinct strains of Brook Trout (domestic and wild-origin strains) to do so. Both strains and sexes of fish were exposed to pulsed-DC electrofishing techniques in a fully factorial design (i.e., male shocked, female shocked, both parents shocked, or neither parent shocked [control]), after which their incubating offspring were monitored for survival to the eyed egg, alevin, and fry stages. We did not detect any effects of our electrofishing treatment or interactions with the sex or strain of the fish exposed to electrofishing, suggesting that electrofishing did not negatively impact gamete viability. Our results support the use of responsible electrofishing to collect spawning salmonids for the purpose of gamete collection for hatchery rearing.
Posterior tibial nerve stimulation improves neurogenic bladder in rats with spinal cord injury through transient receptor potential/P2X signaling pathway
Authors: Song Juan , Cao Xiaoyu , Zhang Akang , Fang Zheng , Xu Jiegou , Gao Xiaoping
Published: February 2022

Background

To study the influences of posterior tibial nerve stimulation (PTNS) on neurogenic bladder and the expression of transient receptor potential (TRP) channels and P2X receptors in rats with spinal cord injury (SCI) and explore the possible mechanism.

Methods

SCI model was established by modified Allen's method and PTNS was performed. Urodynamic indexes and Haematoxylin and Eosine staining of bladder tissue were used to evaluate the therapeutic effect. The expression of TRP channels and P2X receptors in the bladder and dorsal root ganglia (DRG) was detected by real‐time PCR and Western blot.

Results

The low compliance of bladder in treatment group was significantly improved compared with SCI group, and the infiltration of inflammatory cells in bladder tissue was significantly reduced. At the same time, the expression of TRP and P2X in bladder and DRG was partially restored after the treatment of PTNS.

Conclusions

PTNS is an effective therapy for SCI‐induced neurogenic bladder via the TRP/P2X signaling pathway.
Fabrication of thermal conductivity enhanced polymer composites with three‐dimensional networks based on natural cotton
Authors: Zhou Zhengrong , Huang Rongjin , Liu Huiming , Zhang Chi , Zhao Yalin , Miao Zhicong , Wu Zhixiong , Zhao Wanyin , Han Yemao , Li Laifeng
Published: February 2022

Functional fillers prepared by facile natural materials have attracted much attention for their superior engineering performances and promise to replace the traditional, expensive, and environmentally unfriendly fillers. Herein, carbon fiber aerogel (CFA) was prepared by an annealing process of natural cotton. Silicon carbide (SiC)@CFA with antihygroscopic and thermal stability was further obtained by in‐situ growth via template‐assisted chemical vapor deposition method. After that, CFA/Epoxy composites and SiC@CFA/Epoxy composites with enhanced thermal conductivity at low‐loading fraction were prepared by vacuum‐assisted impregnation of epoxy resin. The SiC@CFA/Epoxy composites have higher thermal conductivity (0.404 W/[m·K] at 1.85 wt% filler at room temperature), higher resistivity, smaller coefficient of thermal expansion, and higher glass transition temperature than CFA/Epoxy composites. Furthermore, the thermal conductivity of the pure epoxy resin and the composites were tested from 150 to 370 K, and the ratio of the thermal conductivity of the composites to that of the pure epoxy resin is greater at low temperatures than at room temperature.
Comparison of Bayesian‐derived and first‐order analytic equations for calculation of vancomycin area under the curve
Authors: Olney Katie B. , Wallace Katie L. , Mynatt Ryan P. , Burgess David S. , Grieves Kaitlyn , Willett Austin , Mani Johann , Flannery Alexander H.
Published: February 2022

Introduction

Consensus guidelines recommend targeting a vancomycin area under the curve to minimum inhibitory concentration (AUC24:MIC) ratio of 400–600 to improve therapeutic success and reduce nephrotoxicity. Although guidelines specify either Bayesian software or first‐order equations may be used to estimate AUC24, there are currently no large studies directly comparing these methods.

Objective

To compare calculated vancomycin AUC24 using first‐order equations with two‐drug concentrations at steady state to Bayesian two‐ and one‐concentration estimations.

Methods

This was a single‐center, retrospective cohort study of 978 adult hospitalized patients receiving intravenous vancomycin between 2017 and 2019. Patients were included if they received at least 72 h of vancomycin and had two‐serum drug concentrations obtained. AUC24 was calculated using first‐order analytic (linear), Bayesian two‐concentration, and Bayesian one‐concentration methods for each patient. The InsightRx™ software platform was used to calculate Bayesian AUC24. Pearson's correlation and clinical agreement (based on AUC24 classified as subtherapeutic, therapeutic, or supratherapeutic) were used to assess agreement between methods. Bland–Altman plots were used to assess mean difference (MD) and 95% limits of agreement (LOA).

Results

Excellent agreement was observed between linear and Bayesian two‐concentration methods (r = 0.963, clinical agreement = 87.4%) and Bayesian two‐concentration and one‐concentration methods (r = 0.931, clinical agreement = 88.5%); however, a degree of variability was noted with 95% LOA −99 to 76 (MD = −11.5 mg*h/L) and −92 to 113 (MD = −10.4 mg*h/L), for the respective comparisons. The agreement between linear and Bayesian one‐concentration approaches was less than prior comparisons (r = 0.823, clinical agreement = 76.8%) and demonstrated the greatest amount of variability with 95% LOA −197 to 153 (MD = −21.9 mg*h/L).

Conclusions

Linear and Bayesian two‐concentration methods demonstrated high‐level agreement with acceptable variability and may be considered comparable to estimate vancomycin AUC24. As linear and Bayesian one‐concentration methods demonstrated significant variability and suboptimal agreement, concerns exist surrounding the interchangeability of these methods in clinical practice, particularly at higher extremes of AUC24.
Novel alternating copolyoxamides with high crystallinity and heat resistance
Authors: Gao Yuanbo , Yang Tingting , Wang Xueli , Chen Jizong , He Yong
Published: February 2022

Two series of novel alternating copolyoxamides (PAnT‐alt‐n2 and PAn2‐alt‐62) are synthesized via solution/solid‐state polycondensation (SSP). The alternating structures are analyzed carefully with 1H NMR and 13C NMR spectra. The melting behaviors, thermal stabilities, crystal structures and crystallinities are systematically evaluated by DSC, TGA and WAXD. The results reveal that these alternating copolyoxamides possess almost perfect alternating chain structures and have high melting temperature (Tm > 270 °C), high crystallinity (Xc > 32%) and high decomposition temperature (T5 > 405 °C) as well as low saturated water absorption (<3.5 wt%), which suggests that they have high potential as engineering plastic of high heat resistant.
Precise Capillary‐Assisted Nanoparticle Assembly in Reusable Templates
Authors: Yu Henry S. C. , Conde‐Rubio Ana , Wang Hsiang‐Chu , Martin Olivier J. F. , Boero Giovanni , Brugger Jürgen
Published: February 2022

Capillary‐assisted particle assembly (CAPA) in predefined topographical templates is a scalable method for the precise positioning of nanoscale objects on various surfaces. High‐resolution CAPA templates are typically fabricated by expensive electron‐beam lithography and are used for a single assembly process. To increase the scalability and reduce the costs of the CAPA technique, the fabrication and characterization of reusable templates with nanoscale funnel‐shaped traps for repetitive precise nanoparticle placement are demonstrated. The yield of the first assembly of 100 nm gold nanoparticles (AuNPs) is as high as 94% with a median position offset of about 10 nm. The subsequent transfer process of the AuNPs from the silicon assembly template onto polymer surfaces, such as the elastic polydimethylsiloxane or the inelastic OrmoComp, shows a transfer yield larger than 99%. After the first transfer process, the assembly template is reused, resulting in a position offset and an assembly and transfer yield of this second assembly/transfer step that are comparable to the first ones. The obtained results demonstrate that the nanotemplates made by electron‐beam lithography can be reused for repeatable CAPA processes and thereby eliminate the need for recurring lithography steps for each assembly and thus make the CAPA technique more cost‐efficient.
Alcohol dehydrogenase expression patterns in normal prostate, benign prostatic hyperplasia, and prostatic adenocarcinoma in African American and Caucasian men
Authors: Stamis Sarah A. , Heath Elisabeth I. , Lucas Steven , Boerner Julie , Slusher Leslie B.
Published: February 2022

Background

In situ metabolism of ethanol by alcohol dehydrogenases (ADHs) contributes to oxidative damage of cells and DNA and has been linked to carcinogenesis in numerous epithelial tissues. The goal of this study was to determine expression patterns of ADH1 and ADH7 isozymes in normal, hyperplastic (benign prostatic hyperplasia [BPH]) and neoplastic (prostate cancer [PCa]) prostate. Furthermore, racial differences in ADH expression between African Americans and Caucasians were investigated.

Methods

ADH expression patterns were characterized by density analysis of ADH immunohistochemistry (n = 21) and real‐time RT‐PCR of total RNAs by laser‐capture microdissection (n = 10) and whole tissue formalin‐fixed paraffin embedded prostate biopsies (n = 63).

Results

ADH protein is found in normal prostate and is primarily associated with glandular epithelium. Transcripts of ADH1B are suppressed in PCa compared to BPH (p = 0.0095). Racial differences in ADH7 transcripts exist between African American and Caucasian men. A total of 57.6% of biopsies from African American prostates have detectable ADH7 messenger RNA (mRNA) transcripts compared to the 13.3% of Caucasian prostate biopsies with detectable transcripts (p = 0.0005). This increased frequency of detection contributes to higher mean ADH7 mRNA transcript levels in African Americans (p = 0.001).

Conclusions

To our knowledge this study is the first to report downregulation of ADH1B in neoplastic prostate at the transcriptional level, suggesting protective regulatory functions. ADH7 transcripts were not detectable in all samples and was found in higher frequency and amount in our African American samples. Racial differences in ADH7 within the prostate is a novel finding and should be investigated further.
Sources of Configurational Entropy versus Compositional Trends in Fragility of Inorganic Glass‐Forming Liquids
Authors: Sen Sabyasachi , Chen Hao
Published: February 2022

The effect of the average network connectivity ⟨r⟩ on the configurational entropy S
conf plays a key role in governing the compositional evolution of the fragility index m for chalcogenide, silicate, and phosphate glass‐forming liquids (GFLs). The effect of ⟨r⟩ on S
conf, and thus on m in chalcogenide and phosphate GFLs can be explained using the self‐avoiding walk model for a chain of either chalcogen atoms (e.g., Se) or PO4 tetrahedra, with various degrees of cross‐linking. It is shown that while a disjointed chain is suitable for modeling the inverse relationship between m and ⟨r⟩ in chalcogenides, semiflexible chains with a higher degree of bending stiffness are more appropriate for modeling the phosphate liquids. In contrast, the silicate and aluminosilicate GFLs exhibit a fundamentally different pattern, which is indicative of S
conf being controlled by the structural relaxation of a dynamically percolative network via the chemical exchange between bridging and non‐bridging oxygen. In contrast to silicates and phosphates, in the case of borate and germanate GFLs, the temperature dependence of the relative fractions of B or Ge atoms in multiple coordination states becomes the predominant contributor to the , which is consistent with their apparently anomalous trend of m increasing with ⟨r⟩.
Machine‐learning‐based approach for predicting postoperative skeletal changes for orthognathic surgical planning
Authors: Ma Qingchuan , Kobayashi Etsuko , Fan Bowen , Hara Kazuaki , Nakagawa Keiichi , Masamune Ken , Sakuma Ichiro , Suenaga Hideyuki
Published: February 2022

Background

Manually surgical planning becomes an increasing workload of surgeons because of the fast‐growing patient population. This study introduced a machine‐learning‐based approach to assist surgical planning in orthognathic surgery.

Methods

Both preoperative and one‐year‐later postoperative computerised tomography images of 56 patients were collected. A 12‐layers cascaded deep neural network structure with two successive models was proposed to yield an end‐to‐end solution, where the first model extracts landmarks from 2D patches of 3D volume and the second model predicts postoperative skeletal changes.

Results

The experimental results showed that the model obtained a prediction accuracy of 5.4 mm at the landmark level in 42.9 s. It also represented 74.4% of 3D regions at volume level when compared with the ground truth of human surgeons.

Conclusions

This study demonstrated the feasibility of predicting postoperative skeletal changes for orthognathic surgical planning by using machine learning, showing great potential for reducing the workload of surgeons.
Facile Synthesis of Amides through Transamidation with Iodine under Neat Conditions
Authors: Girase Pankaj S. , Kumar Vishal , Dhawan Sanjeev , Karpoormath Rajshekhar
Published: February 2022

Iodine and NH2OH.HCl mediated transamidation of unactivated amides with a variety of amines under thermal/microwave irradiations. The current strategy is effective for a wide variety of primary, secondary, and tertiary amides and allows formylation, acylation, and benzoylation of various amines. The primary advantages of the current protocol are simple, rapid, absence of metal catalyst, low‐cost starting material as a solvent, and low environmental impact during the synthesis process.
Co/Cu Co‐Catalyzed Carbonylation of Alkyl Iodides and Thioesters
Authors: Wang Lili , Wu Xia , Tian Qingqiang , Li Yahui
Published: February 2022

Inspired by the unique and ubiquitous nature of thioesters, great attention has been focused on the synthesis of thioesters. However, the harsh reaction conditions and equivalent oxidant required can still limit their applications. Here, a salcomine/IPrCuCl co‐catalyzed carbonylative thioalkylation of alkyl iodides using simple thioesters as a thiol surrogate is developed. This catalytic protocol displayed a good functional groups tolerance. The current work provides an inspiring example of the non‐nobel metal‐catalysed carbonylation for the synthesis of chalcogen‐containing compounds.
Direct Synthesis of Ethylene Glycol from Syngas
Authors: Sun Yi‐Lun , Chai Guo‐Liang
Published: February 2022

After decades of development, the reaction conditions for direct synthesis of ethylene glycol (EG) from syngas are still very harsh. The reason for the severe conditions of direct synthesis of EG is revealed by thermodynamic analysis. This review analyzed the reason why all the current studies on direct synthesis of EG from syngas are homogeneous synthesis. Through the evidence of other related studies and the exploration of reaction mechanism, some suggestions for the further investigation of direct synthesis of EG are also put forward. We also summarizes the progress of direct synthesis of EG from syngas in the past decades, and details the current development status. The catalysts, promoters and reaction conditions used for direct synthesis of EG are sorted out.
Two Coordination Polymers@Graphene Hybrid Electrodes for High‐Performance Supercapacitors with Enhanced Rate Capability and Specific Capacitance
Authors: Sun Xuwen , Qu Yan , Wang Guangming , Chen Tingting , Wang Guangning
Published: February 2022

Hybrids of polyoxometalate(POM)/transition‐metal complexes/graphene‐based electrode materials not only integrate the advantages of the individual components completely but also ameliorate the shortcomings to some extent, providing an efficient approach to fabricate high‐performance supercapacitors. In this work, we synthesized two novel isostructural compounds (Co(itmb)4[H2VW12O40] ⋅ 4H2O (1) and Zn(itmb)4[H2VW12O40] ⋅ 3H2O (2)) based on the Keggin ions via a hydrothermal method (itmb=1‐(imidazo‐1‐ly)‐4‐(1,2,4‐triazol‐1‐ylmethyl)benzene). The specific capacitance of 1@50 %graphene (405.3 F g−1) and 2@50 %graphene (339.2 F g−1) were 1.33 and 1.19 times of 1 and 2, respectively. In addition, the 1@50 %graphene (93.5 %) and 2@50 %graphene (96 %) possess higher rate performance than 1 (90 %) and 2 (91 %), suggesting a significant enhancement of the electrical performance.
Fe3O4@RB@LDH: Efficient and Recyclable Photocatalyst Visible‐Light Mediated Synthesis of Pyran and Pyrrolidinone Derivatives and Their Anti‐Microbial Activities
Authors: Dutta Arup , Goswami Munmee , Rabha Jintu , Das Sukanya , Jha Dhruva K. , Nongkhlaw Rishanlang
Published: February 2022

Selective and high yielding synthesis of pyran and pyrrolidinone derivatives through a magnetic layered double hydroxide (LDH) visible light photocatalyst (VLPC)‐promoted reaction is reported. The catalyst was prepared and characterized by various analytical techniques. Since it is magnetic the prepared catalyst could be easily separated from the reaction mixture by using an external magnet. The advantages of this synthetic protocol are good to excellent yields, short reaction times, easy catalyst recovery and recyclability. Also,in vitroantibacterial screening of pyrrolidinone derivative was studied against gram‐positiveBacillus cereus(B. cereus), gram‐negative bacteriaEscherichia coli(E. coli) andS. aureus. Compound9 f[Methyl‐2‐(3‐chlorophenyl)‐2,5‐dihydro‐4‐hydroxy‐5‐oxo‐1‐phenyl‐1H‐pyrrole‐3‐carboxylate] exhibited the maximum activity against all the bacteria tested in the experiment.
Kinetics and Quantum Chemical Analysis of Intramolecular SN2 Reactions by Using Metal Salts and Promoted by Crown Ethers: Contact Ion Pair vs. Separated Nucleophile Mechanism
Authors: Oh Young‐Ho , Yun Wonhyuk , Lee Sungyul , Kim Dong Wook
Published: February 2022

The efficacy of crown ether as a promoter for intramolecular SN2 reactions is presented, along with the underlying mechanism. The crown ether unit is shown to tremendously accelerate the acetoxylation/cyanation of the crown ether substrate 1 using the metal salts KOAc/KCN. Quantum chemical calculations are presented to examine whether KCN/KOAc reacts as a contact ion‐pair (CIP) or as a solvent‐separated ion‐pair (SIP). By comparing the Gibbs free energies of the transition states we predict that the CIP mechanism would be much more favorable than the SIP pathways for SN2 acetoxylation, whereas both routes are comparable for cyanation. Relative stability of pre‐reaction complexes of the two alternative routes is also examined. The pre‐reaction complex for the CIP pathway is much more stable (G lower by >6.0 kcal/mol) than the SIP counterparts for acetoxylation, indicating that experimental observation of this complex might be a direct evidence of the CIP mechanism of SN2 processes.
A Self‐Assembled Matrix System for Cell‐Bioengineering Applications in Different Dimensions, Scales, and Geometries
Authors: Xu Yong , Gaillez Michelle Patino , Zheng Kai , Voigt Dagmar , Cui Meiying , Kurth Thomas , Xiao Lingfei , Rothe Rebecca , Hauser Sandra , Lee Pao‐Wan , Wieduwild Robert , Lin Weilin , Bornhäuser Martin , Pietzsch Jens , Boccaccini Aldo R. , Zhang Yixin
Published: February 2022

Stem cell bioengineering and therapy require different model systems and materials in different stages of development. If a chemically defined biomatrix system can fulfill most tasks, it can minimize the discrepancy among various setups. By screening biomaterials synthesized through a coacervation‐mediated self‐assembling mechanism, a biomatrix system optimal for 2D human mesenchymal stromal cell (hMSC) culture and osteogenesis is identified. Its utility for hMSC bioengineering is further demonstrated in coating porous bioactive glass scaffolds and nanoparticle synthesis for esiRNA delivery to knock down the SOX‐9 gene with high delivery efficiency. The self‐assembled injectable system is further utilized for 3D cell culture, segregated co‐culture of hMSC with human umbilical vein endothelial cells (HUVEC) as an angiogenesis model, and 3D bioprinting. Most interestingly, the coating of bioactive glass with the self‐assembled biomatrix not only supports the proliferation and osteogenesis of hMSC in the 3D scaffold but also induces the amorphous bioactive glass (BG) scaffold surface to form new apatite crystals resembling bone‐shaped plate structures. Thus, the self‐assembled biomatrix system can be utilized in various dimensions, scales, and geometries for many different bioengineering applications.
Find out how to build and lead successful teams
Authors: Simula Brandy L.
Published: February 2022

Building and leading successful teams requires a set of professional skills that hinge on intentional practices and strategies. Yet far too few of us leading teams in higher ed settings have received sufficient — if any — training in how to build and lead teams. If you're feeling overwhelmed by the prospect of learning to lead successful, productive, and inclusive teams, you're not alone.
Vakuummikroelektronik mit Spindt‐Typ Feldemitter Arrays
Authors: Knapp Wolfram
Published: February 2022

Im Jahr 1970 hat mit der Erfindung des Spindt Feldemitter Arrays die rasante Entwicklung der Vakuummikroelektronik begonnen. Spindt Feldemitter Arrays sind spannungsgesteuerte Elektronenquellen mit nanostrukturierten Hightech‐Kathoden, die das Quanten‐Tunneln für die kalte Feldemission bei hohen lokalen Feldstärken ausnutzen. Anhand der Fowler‐Nordheim Theorie wird gezeigt, dass eine hohe geometrische Feldverstärkung bei kleiner Extraktionsspannung unter 100 V die Effizienz der Elektronenfeldemission deutlich erhöht. Das wird im Design durch die Verringerung der Elektrodenabstände unter 1 μm und mit Emitter‐Spitzenradien kleiner 25 nm erreicht. Die Substitution der thermischen Kathoden und viele vakuumelektronische Anwendungsmöglichkeiten zum Beispiel in miniaturisierten Röntgenröhren sind Motivationen stetiger Weiterentwicklungen. Bei Spindt FEAs gibt es aber auch Probleme in der Nutzungsdauer, vor allem wenn sie Durchschlägen in der vakuumelektronischen Anwendung ausgesetzt sind.
The memory time effects for unsteady seas and oceans water flow through the limestone porous medium in the presence of chemical reaction and Soret effects
Authors: Abd El‐Latief A. M. , Abd‐elhameid A. M.
Published: February 2022

In this work, we study the effects of the thermal and diffusion memories in the seas and oceans water using the methodology of fractional calculus for modeling a viscous fluid. In our model, we derive a model with two fractional parameters representing the thermal and diffusion effects for this type of fluid. We formulate a problem of mixed convection heat and mass transfer flow of a viscous fluid through a Limestone porous medium in a vertical channel whose walls are kept at variable temperature and concentration. The influences of heat‐mass memories in the presence of chemical reaction, heat generation/absorption and, the Soret effect are discussed and represented graphically on all variables fields. Also, the influences of Darcy, Prandtl, Schmidt, Grashof parameters are compared with the effect of fractional parameters.
A bispinor formalism for spinning Witten diagrams
Authors: Binder Damon J. , Freedman Daniel Z. , Pufu Silviu S.
Published: February 2022

Abstract

We develop a new embedding-space formalism for AdS4 and CFT3 that is useful for evaluating Witten diagrams for operators with spin. The basic variables are Killing spinors for the bulk AdS4 and conformal Killing spinors for the boundary CFT3. The more conventional embedding space coordinates XI for the bulk and PI for the boundary are bilinears in these new variables. We write a simple compact form for the general bulk-boundary propagator, and, for boundary operators of spin ℓ ≥ 1, we determine its conservation properties at the unitarity bound. In our CFT3 formalism, we identify an $$ \mathfrak{so} $$
so
(5, 5) Lie algebra of differential operators that includes the basic weight-shifting operators. These operators, together with a set of differential operators in AdS4, can be used to relate Witten diagrams with spinning external legs to Witten diagrams with only scalar external legs. We provide several applications that include Compton scattering and the evaluation of an R4 contact interaction in AdS4. Finally, we derive bispinor formulas for the bulk-to-bulk propagators of massive spinor and vector gauge fields and evaluate a diagram with spinor exchange.
Monodromy defects from hyperbolic space
Authors: Giombi Simone , Helfenberger Elizabeth , Ji Ziming , Khanchandani Himanshu
Published: February 2022

Abstract

We study monodromy defects in O(N) symmetric scalar field theories in d dimensions. After a Weyl transformation, a monodromy defect may be described by placing the theory on S1 × Hd−1, where Hd−1 is the hyperbolic space, and imposing on the fundamental fields a twisted periodicity condition along S1. In this description, the codimension two defect lies at the boundary of Hd−1. We first study the general monodromy defect in the free field theory, and then develop the large N expansion of the defect in the interacting theory, focusing for simplicity on the case of N complex fields with a one-parameter monodromy condition. We also use the ϵ-expansion in d = 4 − ϵ, providing a check on the large N approach. When the defect has spherical geometry, its expectation value is a meaningful quantity, and it may be obtained by computing the free energy of the twisted theory on S1 × Hd−1. It was conjectured that the logarithm of the defect expectation value, suitably multiplied by a dimension dependent sine factor, should decrease under a defect RG flow. We check this conjecture in our examples, both in the free and interacting case, by considering a defect RG flow that corresponds to imposing alternate boundary conditions on one of the low-lying Kaluza-Klein modes on Hd−1. We also show that, adapting standard techniques from the AdS/CFT literature, the S1 × Hd−1 setup is well suited to the calculation of the defect CFT data, and we discuss various examples, including one-point functions of bulk operators, scaling dimensions of defect operators, and four-point functions of operator insertions on the defect.
Radiative semileptonic $$ \overline{B} $$ decays
Authors: Papucci Michele , Trickle Tanner , Wise Mark B.
Published: February 2022

Abstract

We consider the form factors for the radiative semileptonic decays $$ \overline{B} $$

B
¯

(v) → D(*)(v′)ℓ$$ \overline{\nu} $$

ν
¯

ℓγ in the kinematic region where the photon momentum, k, is small enough that heavy quark symmetry (HQS) can be applied without the radiated photon changing the heavy quark velocity (i.e., v(′) ∙ k < m(b,c)). We find that HQS is remarkably powerful, leaving only four new undetermined form factors at leading order in 1/m(b,c). In addition, one of them is fixed in terms of the leading order Isgur-Wise function in the kinematic region, v(′) ∙ k < ΛQCD.
BPS indices, modularity and perturbations in quantum K-theory
Authors: Jockers Hans , Mayr Peter , Ninad Urmi , Tabler Alexander
Published: February 2022

Abstract

We study a perturbation family of $$ \mathcal{N} $$
N
= 2 3d gauge theories and its relation to quantum K-theory. A 3d version of the Intriligator-Vafa formula is given for the quantum K-theory ring of Grassmannians. The 3d BPS half-index of the gauge theory is connected to the theory of bilateral hypergeometric q-series, and to modular q-characters of a class of conformal field theories in a certain massless limit. Turning on 3d Wilson lines at torsion points leads to mock modular behavior. Perturbed correlators in the IR regime are computed by determining the UV-IR map in the presence of deformations.
NNLO QCD corrections to weak boson fusion Higgs boson production in the H → b$$ \overline{b} $$ and H → WW* → 4l decay channels
Authors: Asteriadis Konstantin , Caola Fabrizio , Melnikov Kirill , Röntsch Raoul
Published: February 2022

Abstract

We compute the next-to-next-to-leading order QCD corrections to Higgs boson production in weak boson fusion followed by its decay to a b$$ \overline{b} $$

b
¯

pair or to a pair of leptonically-decaying W bosons. Our calculation allows us to compute realistic fiducial cross sections and assess the impact of fiducial cuts applied to the Higgs boson decay products on the magnitude of QCD radiative corrections in weak boson fusion.
Dark matter freeze-out during SU(2)L confinement
Authors: Howard Jessica N. , Ipek Seyda , Tait Tim M. P. , Turner Jessica
Published: February 2022

Abstract

We explore the possibility that dark matter is a pair of vector-like fermionic SU(2)L doublets and propose a novel mechanism of dark matter production that proceeds through the confinement of the weak sector of the Standard Model. This confinement phase causes the Standard Model doublets and dark matter to confine into pions. The dark pions freeze-out before the weak sector deconfines and generate a relic abundance of dark matter. We solve the Boltzmann equations for this scenario to determine the scale of confinement and constituent dark matter mass required to produce the observed relic density. We determine which regions of this parameter space evade direct detection, collider bounds, and successfully produce the observed relic density of dark matter. For a TeV scale pair of vector-like fermionic SU(2)L doublets, we find the weak confinement scale to be ∼ 700 TeV.
Structure and function of an atypical homodimeric actin capping protein from the malaria parasite
Authors: Bendes Ábris Ádám , Kursula Petri , Kursula Inari
Published: February 2022

Apicomplexan parasites, such as Plasmodium spp., rely on an unusual actomyosin motor, termed glideosome, for motility and host cell invasion. The actin filaments are maintained by a small set of essential regulators, which provide control over actin dynamics in the different stages of the parasite life cycle. Actin filament capping proteins (CPs) are indispensable heterodimeric regulators of actin dynamics. CPs have been extensively characterized in higher eukaryotes, but their role and functional mechanism in Apicomplexa remain enigmatic. Here, we present the first crystal structure of a homodimeric CP from the malaria parasite and compare the homo- and heterodimeric CP structures in detail. Despite retaining several characteristics of a canonical CP, the homodimeric Plasmodium berghei (Pb)CP exhibits crucial differences to the canonical heterodimers. Both homo- and heterodimeric PbCPs regulate actin dynamics in an atypical manner, facilitating rapid turnover of parasite actin, without affecting its critical concentration. Homo- and heterodimeric PbCPs show partially redundant activities, possibly to rescue actin filament capping in life cycle stages where the β-subunit is downregulated. Our data suggest that the homodimeric PbCP also influences actin kinetics by recruiting lateral actin dimers. This unusual function could arise from the absence of a β-subunit, as the asymmetric PbCP homodimer lacks structural elements essential for canonical barbed end interactions suggesting a novel CP binding mode. These findings will facilitate further studies aimed at elucidating the precise actin filament capping mechanism in Plasmodium.
Alterations in calmodulin-cardiac ryanodine receptor molecular recognition in congenital arrhythmias
Authors: Dal Cortivo Giuditta , Barracchia Carlo Giorgio , Marino Valerio , D’Onofrio Mariapina , Dell’Orco Daniele
Published: February 2022

Calmodulin (CaM), a ubiquitous and highly conserved Ca2+-sensor protein involved in the regulation of over 300 molecular targets, has been recently associated with severe forms of lethal arrhythmia. Here, we investigated how arrhythmia-associated mutations in CaM localized at the C-terminal lobe alter the molecular recognition with Ryanodine receptor 2 (RyR2), specifically expressed in cardiomyocytes. We performed an extensive structural, thermodynamic, and kinetic characterization of the variants D95V/H in the EF3 Ca2+-binding motif and of the D129V and D131H/E variants in the EF4 motif, and probed their interaction with RyR2. Our results show that the specific structural changes observed for individual CaM variants do not extend to the complex with the RyR2 target. Indeed, some common alterations emerge at the protein–protein interaction level, suggesting the existence of general features shared by the arrhythmia-associated variants. All mutants showed a faster rate of dissociation from the target peptide than wild-type CaM. Integration of spectroscopic data with exhaustive molecular dynamics simulations suggests that, in the presence of Ca2+, functional recognition involves allosteric interactions initiated by the N-terminal lobe of CaM, which shows a lower affinity for Ca2+ compared to the C-terminal lobe in the isolated protein.