bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment of Noise Pollution from Petrol Generators in Nigeria: An Analysis of Distance, Capacity and Age Variables
Authors: Nwabueze Onwe David , Chijioke Okafor Victor , Blessed Nathaniel Samuel
Published: November 2024

Irregular and epileptic power supply in Nigerian, parts of Africa and some other parts of the globe has made electricity generators the primary source of power for domestic and commercial purposes in such places. These generators produce noise pollution in the environment. Noise pollution is hazardous to human hearing and health and it adversely affect plant growth and development. This study investigated the noise generated from five different capacity gasoline generators of varying ages at varying distances, representing the range of petrol generator for both domestic and commercial uses in Nigeria. Five petrol generators of varying capacities 2, 3, 6, 10 and 14 kilo Volt Ampere (kVA), and age 1, 2, 3, 4, 5 years respectively were used for the experiment. The sound level from the generators were measured at varying distances of 0, 5, 10, 15 and 20 m respectively using a digital sound level meter. Two-way Analysis of Variance (ANOVA) was used to test the difference between generators of different ages at the varying distances (α = 0.05). The sound intensity decreased as distance from the generators increased. The lowest sound was recorded for the generators of age 1, and increased as the age of the generators increased. For the capacity of generators tested, weighted (A) sound level produced by 1 year old generators at distances 0-20 m from the generator ranged from 60.9-83 dB (A) for 2 kVA generator; 60.2-84.1 dB (A) for 3 kVA generator; 64.7-86 dB (A) for 6 kVA generator; 66.52-88.02 dB (A) for 10 kVA generator; 70-91.8 dB (A) for 14 kVA generator respectively. The study showed that sound levels from generators increased as they aged. The sound levels from all the generators indicate noise pollution, as they are, on average, above the World Health Organization's specified limits of 30 and 70 decibels for indoor and outdoor environments, respectively. Consequently, the sound generated by various petrol generators is a significant source of noise pollution.
Cultural Behavior of Vietnamese High School Teachers in Online Teaching: Current Status and Implications
Authors: Thuy Bui Thanh , Nguyen Xuan-An , Anh Nguyen Thi Kieu , Ha Vo Thanh , Ngoan Nguyen Thi Quynh , Ha Nguyen Thi Viet
Published: November 2024

Although online teaching has become widespread, few studies have specifically examined teachers' cultural behavior within this context in Vietnam. To investigate teachers' cultural behavior, this article draws on theories of social behavior, interaction, media richness, and models of online communication. A quantitative survey using a structured questionnaire was conducted with 321 teachers and 602 high school students from multiple schools across three provinces/cities representing Vietnam's three regions (Hanoi in the North, Nghe An in the Central region, and Ho Chi Minh City in the South). The survey results indicate that some teachers still lack communication skills and exhibit inappropriate behaviors in the online environment. There are notable differences between teacher and student evaluations, and factors such as gender and teaching experience are found to influence teacher behavior. Based on these findings, the paper proposes strategies to enhance communication skills and cultural behavior in online teaching.
LESBOFEMINISMO NA BAHIA: UM ESTUDO SOBRE O GRUPO LÉSBICO DA BAHIA (1993-2003)
Authors: Da Silva Zuleide Paiva , Araujo Janja , Vieira de Jesus Rosana Meire
Published: November 2024

Estudos apontam que os movimentos de lésbicas no Brasil têm sua história imbricada aos movimentos LGBT e feministas, embora deveras invisibilizados por todos eles. Porém, passados mais de quatro décadas, desde sua origem atrelada à efervescência dos movimentos sociais urbanos que protagonizaram a luta por direitos e cidadania nos anos 70-80, ainda faz-se necessário reafirmar o papel fundamental das lésbicas feministas na luta contra a lesbofobia e na construção do estado democrático de direitos que se consolidou no Brasil na metade dos anos 80. Ainda hoje, quando as manifestações de preconceitos de todas as ordens permanecem tão atuais, é preciso, sobretudo, ressaltar o lugar político das ações formativas das ativistas lesbofeministas no enfrentamento à lesbofobia, ao racismo, sexismo e embates de classe. Com esse desafio, este texto assume os estudos sobre a lesbianidade no campo feminista com o propósito de refletir o papel educador do GLB– Grupo Lésbico da Bahia, primeira organização não governamental lésbica do Norte e Nordeste do Brasil, criada em 1993 e extinta em 2003. Para tanto, assume a experiência como ponto de partida e recorre às fontes bibliográfica, documental, oral e à memória subjetiva, apontando como resultado uma cartografia aberta do pensamento/movimento do GLB.
A VIOLÊNCIA POLÍTICA DE GÊNERO NA CPI DA COVID-19
Authors: Andrade Lima Elizabeth Christina de , Costa Ana Paula Guedes do Nascimento
Published: November 2024

As mulheres têm assumido diversas posições no cenário político, no entanto, os dados ainda ensejam um quadro de sub-representação neste espaço, apesar delas adentrarem nesse meio de maneira qualificada. A presença e participação delas na política tem suscitado o recrudescimento de um fenômeno: a violência política de gênero. Esta tem como objetivo, desestimular e cercear a presença e fala das mulheres, além de expor sua vida privada, a fim de ridicularizá-las e estigmatizá-las, enquadrando-as nos mais variados estereótipos de gênero. O objetivo do artigo se concentra na definição do termo violência política de gênero como uma categoria de análise, tomando como caso a instauração e execução da CPI da Covid 19. O objetivo é contribuir com a percepção de que a violência política de gênero é uma realidade que afasta e limita a atividade de mulheres na política partidária e que precisa ser nomeada, definida e combatida, como meio de garantir às mulheres seus direitos políticos e a completude da democracia representativa.
QUESTÕES DE GÊNERO NAS BRINCADEIRAS INFANTIS
Authors: Menezes Marcela Barbosa de , Menezes Márcia Barbosa de
Published: November 2024

O presente artigo se propõe a apresentar uma leitura inicial acerca dos estudos relativos às questões de gênero no contexto das brincadeiras infantis. Para tanto, foi realizada uma revisão narrativa da literatura, bem como uma busca pelas produções científicas nacionais na área da psicologia do desenvolvimento produzidas nos últimos 5 anos sobre o assunto. Conclui-se que a produção brasileira sobre o tema é incipiente na referida área, havendo poucos trabalhos que realmente se propõem a discutir as questões de gênero no âmbito do brincar infantil como objeto principal. Assim, revela-se a necessidade da produção de estudos voltados para a referida temática na área da psicologia do desenvolvimento.
A HIPERANDROGENIA NO ATLETISMO E O REGIME DA MEDICALIZAÇÃO COMPULSÓRIA
Authors: Santos Ana Lúcia
Published: November 2024

Discursos científicos e culturais em torno da testosterona têm classificado esta hormona como produtora de uma masculinidade universal e patologizado a sua presença em corpos designados do sexo feminino. É sob este viés que várias organizações desportivas restringem o acesso à competição de mulheres com hiperandrogenia, por considerarem valores elevados de testosterona conferem vantagem injusta sobre as restantes competidoras. Este artigo propõe desconstruir a conceção da testosterona enquanto hormona pertencente ao domínio de uma masculinidade cisgénero e considerá-la uma substância de interesse a todos os corpos independemente do sexo. Para auxiliar esta tarefa são analisadas as normas da entidade máxima do atletismo, a World Athletics, relativas à elegibilidade de mulheres com hiperandrogenia no atletismo.
FEMINISMO RADICAL, CRÍTICA DE GÊNERO E A LUTA PELOS DIREITOS BASEADOS NO SEXO
Authors: Jordão Martinez Fabiana
Published: November 2024

Este artigo objetiva de um lado, descrever e analisar as reivindicações do Feminismo Radical contemporâneo e de outro, compreender a experiência de se tornar uma ativista. O objetivo do Feminismo Radical tem sido  “reconstituir a categoria mulher” com base no sexo através de uma crítica ao conceito de gênero, a entrada de transativistas no feminismo e ao que consideram a redução dos espaços, políticas e pautas destinadas as mulheres. Primeiro, mostro como o Feminismo Radical está em consonância com a atual tendência materialista das teorias críticas. Em seguida, exploro os dados de um survey executado em em 2021 sobre os motivos e as experiências que tem impelido cada vez mais mulheres ao Feminismo Radical. Por fim, mostro que as reivindicações por direitos descritas na Declaração da Woman´s Declaration Internacional Brasil (WDI Brasil) estão em consonância com estas experiências.
Palavras chaves: Feminismo Radical, experiências, crítica a gênero, colisão de direitos.
1‐Hydroxy‐xanthine derivatives inhibit the human Caf1 nuclease and Caf1‐containing nuclease complexes via Mg2+‐dependent binding
Authors: Airhihen Blessing , Pavanello Lorenzo , Jadhav Gopal P. , Fischer Peter M. , Winkler Gerlof Sebastiaan
Published: February 2019

In eukaryotic cells, cytoplasmic mRNA is characterised by a 3′ poly(A) tail. The shortening and removal of poly(A) tails (deadenylation) by the Ccr4‐Not nuclease complex leads to reduced translational efficiency and RNA degradation. Using recombinant human Caf1 (CNOT7) enzyme as a screening tool, we recently described the discovery and synthesis of a series of substituted 1‐hydroxy‐3,7‐dihydro‐1H‐purine‐2,6‐diones (1‐hydroxy‐xanthines) as inhibitors of the Caf1 catalytic subunit of the Ccr4‐Not complex. Here, we used a chemiluminescence‐based AMP detection assay to show that active 1‐hydroxy‐xanthines inhibit both isolated Caf1 enzyme and human Caf1‐containing complexes that also contain the second nuclease subunit Ccr4 (CNOT6L) to a similar extent, indicating that the active site of the Caf1 nuclease subunit does not undergo substantial conformational change when bound to other Ccr4‐Not subunits. Using differential scanning fluorimetry, we also show that binding of active 1‐hydroxy‐xanthines requires the presence of Mg2+ ions, which are present in the active site of Caf1.
Nesiarch
Authors: Scholten Joseph B.
Published: February 2019

The nesiarch was the head of the League of the Islanders set up in the Cyclades in the early Hellenistic era. The position exemplifies the administrative structures developed by the Hellenistic monarchies to solidify control over their new realms, and the opportunities those structures offered to talent and ambition among Greeks and Makedonians.
Impact of aeration change and beam arrangement on the robustness of proton plans
Authors: Shusharina Nadya , Fullerton Barbara , Adams Judy A. , Sharp Gregory C. , Chan Annie W.
Published: February 2019

This study determines the impact of change in aeration in sinonasal cavities on the robustness of passive‐scattering proton therapy plans in patients with sinonasal and nasopharyngeal malignancies. Fourteen patients, each with one planning CT and one CT acquired during radiotherapy were studied. Repeat and planning CTs were rigidly aligned and contours were transferred using deformable registration. The amount of air, tumor, and fluid within the cavity containing the tumor were measured on both CTs. The original plans were recalculated on the repeat CT. Dosimetric changes were measured for the targets and critical structures. Median decrease in gross tumor volume (GTV) was 19.8% and correlated with the time of rescan. The median change in air content was 7.1% and correlated with the tumor shrinkage. The median of the mean dose Dmean change was +0.4% for GTV and +0.3% for clinical target volume. Median change in the maximum dose Dmax of the critical structures were as follows: optic chiasm +0.66%, left optic nerve +0.12%, right optic nerve +0.38%, brainstem +0.6%. The dose to the GTV decreased by more than 5% in 1 case, and the dose to critical structure(s) increased by more than 5% in three cases. These four patients had sinonasal cancers and were treated with anterior proton fields that directly transversed through the involved sinus cavities. The change in dose in the replanning was strongly correlated with the change in aeration (P = 0.02). We found that the change in aeration in the vicinity of the target and the arrangement of proton beams affected the robustness of proton plan.
Solution‐Processed Self‐Powered Transparent Ultraviolet Photodetectors with Ultrafast Response Speed for High‐Performance Communication System
Authors: Fang Huajing , Zheng Cheng , Wu Liangliang , Li Yi , Cai Jian , Hu Mingxiang , Fang Xiaosheng , Ma Rong , Wang Qing , Wang Hong
Published: February 2019

Transparent ultraviolet (UV) photodetectors are an essential component of next‐generation “see‐through” electronics. However, the current photodetectors often suffer from relatively slow response speeds and high driving voltages. Here, all‐solution‐processed UV photodetectors are reported that are facilely prepared from environmentally friendly and abundant materials. The UV photodetectors are composed of a titanium dioxide thin film as the photosensitive layer sandwiched between two different transparent electrodes to form asymmetric Schottky junctions. The photodetector with high optical transparency can operate at zero bias because of spontaneous separation of photogenerated electron–hole pairs by the built‐in electric field. The resulting self‐powered photodetector displays high sensitivity to broadband UV light (200–400 nm). In particular, an ultrafast response speed up to 44 ns is obtained, representing a significant improvement over those of the conventional transparent photodetectors. Moreover, the photodetector has been successfully applied, for the first time, in a UV communication system as the self‐powered signal receiver. This work uniquely combines the features of high optical transparency and self‐power ability into UV photodetectors and would enable a broad range of optoelectronic applications.
Regio‐ and Stereoselective Synthesis of 3‐Pyrazolylidene‐2‐oxindole Compounds by Nucleophilic Vinylic Substitution of (E)‐3‐(Nitromethylene)indolin‐2‐one
Authors: Vila Carlos , Slack Sophie , Blay Gonzalo , Muñoz M. Carmen , Pedro José R.
Published: February 2019

A highly regio‐ and stereoselective synthesis of 3‐alkylidene‐2‐oxindoles has been described through a nucleophilic vinylic substitution (SNV) of (E)‐3‐(nitromethylene)indolin‐2‐one using pyrazol‐3‐ones as nucleophiles and Et3N as a base. The reaction affords selectively the Z‐isomer when pyrazol‐3‐ones without substituents at the 4 position are used. While the reaction is E‐selective with 4‐substituted pyrazolones. The stereoselectivity (up to >20:1) and the yields (up to 98%) are very high under mild reaction conditions.

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Brønsted acid Catalysed Synthesis of 3‐(2‐Alkoxyethyl)indoles from α‐Arylaminocyclobutanones and Alcohols
Authors: Serusi Lorenzo , Bonnans Marie , Luridiana Alberto , Secci Francesco , Caboni Pierluigi , Boddaert Thomas , Aitken David J. , Frongia Angelo
Published: February 2019

A new Brønsted acid catalysed solvent‐free cascade reaction consisting of a ring closure‐ring fission process between α‐arylaminocyclobutanones and alcohols has been established, providing highly functionalised 3‐(2‐alkoxyethyl)indoles in good to excellent yields.

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Molecular Mechanisms of DNA Replication and Repair Machinery: Insights from Microscopic Simulations
Authors: Maffeo Christopher , Chou Han‐Yi , Aksimentiev Aleksei
Published: February 2019

Reproduction, the hallmark of biological activity, requires making an accurate copy of the genetic material to allow the progeny to inherit parental traits. In all living cells, the process of DNA replication is carried out by a concerted action of multiple protein species forming a loose protein–nucleic acid complex, the replisome. Proofreading and error correction generally accompany replication but also occur independently, safeguarding genetic information through all phases of the cell cycle. Advances in biochemical characterization of intracellular processes, proteomics, and the advent of single‐molecule biophysics have brought about a treasure trove of information awaiting to be assembled into an accurate mechanistic model of the DNA replication process. This review describes recent efforts to model elements of DNA replication and repair processes using computer simulations, an approach that has gained immense popularity in many areas of molecular biophysics but has yet to become mainstream in the DNA metabolism community. It highlights the use of diverse computational methods to address specific problems of the fields and discusses unexplored possibilities that lie ahead for the computational approaches in these areas.
Graphene–Graphite Polyurethane Composite Based High‐Energy Density Flexible Supercapacitors
Authors: Manjakkal Libu , Navaraj William Taube , Núñez Carlos García , Dahiya Ravinder
Published: February 2019

Energy autonomy is critical for wearable and portable systems and to this end storage devices with high‐energy density are needed. This work presents high‐energy density flexible supercapacitors (SCs), showing three times the energy density than similar type of SCs reported in the literature. The graphene–graphite polyurethane (GPU) composite based SCs have maximum energy and power densities of 10.22 µWh cm−2 and 11.15 mW cm−2, respectively, at a current density of 10 mA cm−2 and operating voltage of 2.25 V (considering the IR drop). The significant gain in the performance of SCs is due to excellent electroactive surface per unit area (surface roughness 97.6 nm) of GPU composite and high electrical conductivity (0.318 S cm−1). The fabricated SCs show stable response for more than 15 000 charging/discharging cycles at current densities of 10 mA cm−2 and operating voltage of 2.5 V (without considering the IR drop). The developed SCs are tested as energy storage devices for wide applications, namely: a) solar‐powered energy‐packs to operate 84 light‐emitting diodes (LEDs) for more than a minute and to drive the actuators of a prosthetic limb; b) powering high‐torque motors; and c) wristband for wearable sensors.
Ecology of Sites of Confinement: Everyday Life in a Detention Center for Illegalized Non‐citizens
Authors: Esposito Francesca , Ornelas José , Briozzo Erica , Arcidiacono Caterina
Published: February 2019

Highlights

In spite of concerns about migration‐related detention, research inside these sites of confinement is scarce.

We present an ethnographic exploration into the detention of illegalized non‐citizens in Italy.

Transcending individual‐centered analysis, we adopt an ecological framework with a focus on justice.

We contribute to create knowledge on the psychosocial and cultural world behind the walls of detention.

We discuss the oppressive qualities of detention and avenues for research and action for community psychologists.
Protective effects of α‐lipoic acid on cultured human nasal fibroblasts exposed to urban particulate matter
Authors: Lee Dong Chang , Choi Hyunsu , Oh Jeong‐Min , Lee Do Hee , Kim Sung Won , Kim Soo Whan , Kim Byung Guk , Cho Jin Hee , Lee Joohyung
Published: February 2019

Background

Exposure to urban particulate matter (UPM) has been studied as a cause of various health problems. Although the association between UPM and the respiratory tract has been well studied, further research is required to characterize the effects of UPM on the upper respiratory tract. We investigated the effects of UPM‐induced reactive oxygen species (ROS) production on cultured human nasal fibroblasts, as well as the protective effects of α‐lipoic acid (ALA) on ROS production and the underlying signaling pathways involved in ROS inhibition.

Methods

Human turbinate tissue specimens were collected from 6 patients. The effects of UPM on the viability of cultured nasal fibroblasts were determined. A fluorescent malondialdehyde assay was used to measure ROS levels. Real‐time reverse transcription polymerase chain reaction was used to measure the messenger RNA levels of genes encoding Nrf2, the antioxidant response elements (AREs) (HO‐1, NQO1), and the proinflammatory cytokines (interleukin‐6 and interleukin‐8) before and after ALA treatment. Western blotting analyses were used to measure nuclear and cytosolic Nrf2 and AREs.

Results

UPM reduced cell viability and increased ROS expression in nasal fibroblasts. ALA treatment decreased ROS production in UPM‐exposed fibroblasts via the Nrf2, HO‐1, and NQO‐1 pathways. Also, ALA treatment abrogated increases in the interleukin‐6 and ‐8 levels induced by UPM in nasal fibroblasts.

Conclusion

UPM exposure resulted in increased ROS production in nasal fibroblasts. ALA treatment inhibited this increase via the Nrf2 pathway, suggesting that ALA may have a protective effect against rhinitis caused by ROS expression induced by exposure to UPM.
A Novel Strategy for the Construction of Covalent Organic Frameworks from Nonporous Covalent Organic Polymers
Authors: Miao Zhuang , Liu Guiyan , Cui Yumeng , Liu Zhengyu , Li Jinheng , Han Fangwai , Liu Yu , Sun Xiaoxiao , Gong Xuefang , Zhai Yufeng , Zhao Yanli , Zeng Yongfei
Published: February 2019

The field of covalent organic frameworks (COFs) has been developed significantly in the past decade on account of their important characteristics and vast application potential. On the other hand, the discovery of novel synthetic methodology is still a challenging task to further promote the preparation of COFs. Herein, an interesting protocol for the conversion of amorphous nonporous covalent organic polymers (COPs) to COFs was established, affording four COFs with high crystallinity and porosity. Specifically, imine‐linked amorphous COP‐1 was successfully converted to COF‐1–4 by replacing one type of linker with other organic building blocks. The realization of this conversion provides a facile method for constructing COFs from COPs.
(3+3)‐Annulation of Carbonyl Ylides with Donor–Acceptor Cyclopropanes: Synergistic Dirhodium(II) and Lewis Acid Catalysis
Authors: Petzold Martin , Jones Peter G. , Werz Daniel B.
Published: February 2019

The first (3+3)‐annulation process of donor–acceptor cyclopropanes using synergistic catalysis is reported. The Rh2(OAc)4‐catalyzed decomposition of diazo carbonyl compounds generated carbonyl ylides in situ. These 1,3‐dipoles were converted with donor–acceptor cyclopropanes, activated by Lewis acid catalysis, to afford multiply substituted pyran scaffolds in high yield and diastereoselectivity. Extensive optimization studies enabled access to 9‐oxabicyclo[3.3.1]nonan‐2‐one and 10‐oxabicyclo[4.3.1]decen‐2‐ol cores, exploiting solvent effects on intermediate reactivity.
Identification of Flavin Mononucleotide as a Cell‐Active Artificial N6‐Methyladenosine RNA Demethylase
Authors: Xie Li‐Jun , Yang Xiao‐Ti , Wang Rui‐Li , Cheng Hou‐Ping , Li Zhi‐Yan , Liu Li , Mao Lanqun , Wang Ming , Cheng Liang
Published: February 2019

N6‐Methyladenosine (m6A) represents a common and highly dynamic modification in eukaryotic RNA that affects various cellular pathways. Natural dioxygenases such as FTO and ALKBH5 are enzymes that demethylate m6A residues in mRNA. Herein, the first identification of a small‐molecule modulator that functions as an artificial m6A demethylase is reported. Flavin mononucleotide (FMN), the metabolite produced by riboflavin kinase, mediates substantial photochemical demethylation of m6A residues of RNA in live cells. This study provides a new perspective to the understanding of demethylation of m6A residues in mRNA and sheds light on the development of powerful small molecules as RNA demethylases and new probes for use in RNA biology.
The Fluorination of C−H Bonds: Developments and Perspectives
Authors: Szpera Robert , Moseley Daniel F. J. , Smith Lewis B. , Sterling Alistair J. , Gouverneur Véronique
Published: February 2019

This Review summarizes advances in fluorination by C(sp2)−H and C(sp3)−H activation. Transition‐metal‐catalyzed approaches championed by palladium have allowed the installation of a fluorine substituent at C(sp2) and C(sp3) sites, exploiting the reactivity of high‐oxidation‐state transition‐metal fluoride complexes combined with the use of directing groups (some transient) to control site and stereoselectivity. The large majority of known methods employ electrophilic fluorination reagents, but methods combining a nucleophilic fluoride source with an oxidant have appeared. External ligands have proven to be effective for C(sp3)−H fluorination directed by weakly coordinating auxiliaries, thereby enabling control over reactivity. Methods relying on the formation of radical intermediates are complementary to transition‐metal‐catalyzed processes as they allow for undirected C(sp3)−H fluorination. To date, radical C−H fluorinations mainly employ electrophilic N−F fluorination reagents but a unique MnIII‐catalyzed oxidative C−H fluorination using fluoride has been developed. Overall, the field of late‐stage nucleophilic C−H fluorination has progressed much more slowly, a state of play explaining why C−H 18F‐fluorination is still in its infancy.
A Neutral Geminal Tin/Phosphorus Frustrated Lewis Pair
Authors: Holtkamp Philipp , Friedrich Felix , Stratmann Erik , Mix Andreas , Neumann Beate , Stammler Hans‐Georg , Mitzel Norbert W.
Published: February 2019

The geminal frustrated Lewis pair (FLP) (F5C2)3SnCH2P(tBu)2 (2) was prepared by reacting (F5C2)3SnCl with LiCH2P(tBu)2. It is neutral and contains an extremely electronegatively substituted, but relatively soft (hard–soft acid–base, HSAB) acidic tin function. Its FLP‐type reactivity was proven by reaction with a variety of small molecules (CO2, SO2, CS2, PhNCO, HCl, (Ph3P)AuCl). However, it shows no reaction in H/D scrambling experiments with H2/D2 mixtures and binds CO2 reversibly, as was observed by VT‐NMR spectroscopy. Compound 2 and all its adducts were completely characterized by means of multinuclear NMR spectroscopy, elemental analysis, and X‐ray diffraction experiments.
Roles of the molecular weight of n‐ethylene glycol diacrylates and UV irradiance on the mechanical properties at the gel point of acrylic acid based hydrogels
Authors: Magami Saminu M. , Williams Rhodri L.
Published: February 2019

We investigated sol–gel transitions in acrylic acid based hydrogels with real time in situ photocrosslinking and Fourier transform mechanical spectroscopy. Crosslinkable n‐ethylene glycol diacrylate (EGDA) compounds with molecular weights (MWs) in the range 171–575 g/mol were used in standard solutions of known polyacrylamide. The mutation number (Nmu) was monitored in all of the experiments, such that Nmu was 0.3 or lower at all of the experimental frequencies. During gelation, a frequency independence of tan δ was observed in all cases, such that the storage and loss moduli were scaled as about ω
n; this indicated the establishment of a sample spanning network in the hydrogels with the Winter–Chambon criteria. The relaxation exponents (ns) ranged from 0.35 to 0.81 when they were affected by both the MWs of the EGDAs and the UV irradiance. The stiffness of the critical gels steadily increased with increases in both the MWs of the EGDAs and the UV irradiance. The fractal dimensions decreased at the gel point with increasing MWs of the EGDAs, whereas it increased with an increase in the UV irradiance. An optimization tool (Design‐Expert) was used to compare the effects and interactions of the reaction parameters on the gel‐time characteristics of the critical gels and those of the fully formed hydrogels. A map (description) of the reaction parameters that can be used in the design of specific networks, particularly with values of n that are close to or equal to 0.5, is proposed. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47606.
Knowledge withholding in online knowledge spaces: Social deviance behavior and secondary control perspective
Authors: Shen Xiao‐Liang , Li Yang‐Jun , Sun Yongqiang , Chen Jun , Wang Feng
Published: February 2019

Knowledge withholding, which is defined as the likelihood that an individual devotes less than full effort to knowledge contribution, can be regarded as an emerging social deviance behavior for knowledge practice in online knowledge spaces. However, prior studies placed a great emphasis on proactive knowledge behaviors, such as knowledge sharing and contribution, but failed to consider the uniqueness of knowledge withholding. To capture the social‐deviant nature of knowledge withholding and to better understand how people deal with counterproductive knowledge behaviors, this study develops a research model based on the secondary control perspective. Empirical analyses were conducted using the data collected from an online knowledge space. The results indicate that both predictive control and vicarious control exert a positive influence on knowledge withholding. This study also incorporates knowledge‐withholding acceptability as a moderating variable of secondary control strategies. In particular, knowledge‐withholding acceptability enhances the impact of predictive control, whereas it weakens the effect of vicarious control on knowledge withholding. This study concludes with a discussion of the key findings, and the implications for both research and practice.
Frontal lobe dysfunction underlies the differential word retrieval impairment in adolescents with high‐functioning autism
Authors: Yeung Michael K. , Lee Tsz L. , Chan Agnes S.
Published: February 2019

There is substantial evidence of word retrieval impairment as indicated by poor performance on the category fluency test in autism spectrum disorder (ASD). However, little is known about the neural mechanisms underlying this impairment. Functional neuroimaging studies have shown that the lateral frontal cortex plays a key role in flexible word retrieval. Thus, we examined whether individuals with ASD exhibited altered frontal processing during the category fluency test using functional near‐infrared spectroscopy (fNIRS). Twenty‐two adolescents with high‐functioning ASD (20 males) and 22 typically developing (TD) adolescents (16 males) aged 11–18 years were recruited. All underwent a category fluency paradigm, which required production of animal or means of transportation words for 1 min each although their frontal hemodynamic changes were recorded with fNIRS. We found that adolescents with ASD produced fewer animal but not transportation words (group‐by‐category interaction: P = 0.003), suggesting differential word retrieval impairment. In addition, unlike TD adolescents who exhibited activation primarily in lateral frontal regions during word production, adolescents with ASD had comparable activation across lateral and medial frontal regions. More importantly, this lack of lateral–medial distinction of activation, which was associated with poor word retrieval, differed significantly between groups only in the animal category (group‐by‐category interaction: P = 0.018). Thus, our findings implicate frontal lobe dysfunction in the impairment of differential word retrieval in adolescents with ASD. The relatively greater involvement of the medial frontopolar cortex might reflect the use of nonspecialized brain regions to compensate for the category‐dependent difficulties with word retrieval in ASD. Autism Res 2019, 12: 600–613. © 2019 International Society for Autism Research, Wiley Periodicals, Inc.

Lay Summary

Using an optical imaging tool, we found that adolescents with autism had difficulties with producing semantically related words and exhibited frontal lobe dysfunction. Nonetheless, poor word production and altered brain processing was only seen when these adolescents were asked to produce words from a category of living things but not nonliving things (i.e., animals but not means of transportation). Category‐dependent word retrieval problems and frontal lobe dysfunction might be two features of this disorder.
Baukosten und Energieeffizienz von Mehrfamilienhäusern
Authors: Schuberth Jens
Published: February 2019

Seit 2001 prämiert der Deutsche Bauherrenpreis vorbildliche Neubauten und Sanierungen von Mehrfamilienhäusern. Eine Analyse der neueren Projekte zeigt, dass Wohnungswirtschaft und Planer ein überaus leistungsstarkes Team bilden, welches wirtschaftliches und energieeffizientes Bauen sehr gut vereinbaren kann. Eine hohe Energieeffizienz wirkt sich bei Mehrfamilienhäusern in höchstens geringem Umfang auf die Baukosten auswirken, sowohl bei Neubauten als auch bei Sanierungen. Bei Kaltmieten hat der Standort in einer Großstadt großen Einfluss; Häuser mit niedrigem Primärenergiebedarf werden sogar günstiger vermietet. Pauschale Behauptungen, Anforderungen an die Energieeffizienz von Gebäuden führten zu überhöhten Baukosten und Kaltmieten, erweisen sich vor dem Hintergrund dieser Auswertung anspruchsvoller Projekte als nicht haltbar. Gutachten über die Wirtschaftlichkeit von Energiestandards sollten nicht nur Materialpreise, sondern die Baukosten realisierter Projekte untersuchen und dabei stets mit statistisch abgesicherten Methoden (oder wenigstens mit Bandbreiten) arbeiten.
Ansätze zur ökonomischen Bewertung vertikaler Begrünungssysteme
Authors: Hollands Jutta , Korjenic Azra
Published: February 2019

Vertikale Begrünung kann einen wesentlichen Beitrag zu einer nachhaltigen Stadtentwicklung leisten. Denn Begrünung kann nicht nur die bauphysikalischen Eigenschaften von Gebäuden verbessern und als Schadstofffilter zur Verbesserung der Luftqualität beitragen, sondern auch großen Einfluss auf die betroffenen Menschen haben. Eine Begrünungsmaßnahme im Rahmen einer Bestandssanierung oder bei einem Neubau durchzuführen, ist nicht zuletzt von den entstehenden Kosten und den möglichen Nutzen abhängig. Das Ziel der durchgeführten Forschung besteht darin, ein Basismodell zu entwickeln, mit dem in weiterer Folge objektbezogen die Kosten und Nutzen für wandgebundene Begrünungssysteme abgeschätzt werden können. Hierzu wird für jedes System ein gesamter Lebenszyklus von der Errichtung über die Nutzung bis zur schlussendlichen Entsorgung betrachtet. Aufgrund der fehlenden Messbarkeit und quantitativen Bewertbarkeit vieler positiver Auswirkungen von Gebäudebegrünung kann derzeit kein ganzheitliches Modell vorgezeigt werden, sondern lediglich der entwickelte, leicht erweiterbare Ansatz zur ökonomischen Bewertung präsentiert werden. Dank dieses Modells konnten bereits wertvolle Erkenntnisse zur Systemoptimierung erlangt werden und Anknüpfungspunkte für weitere Bewertungsmöglichkeiten definiert werden.
Einsatz passiver Erdreichkühlung zur Konditionierung von Lagerhäusern
Authors: Gratzl Markus , Zieser Johannes , Retter Philipp
Published: February 2019

Für den Neubau der Produktionsstätte eines Getränkeherstellers war es erforderlich, ein Lagervolumen für rund fünf Millionen Flaschen als gekühltes Rohsektlager bereitzustellen. Die maximalen Temperaturen durften aufgrund der Qualitätsanforderungen im Produktionsprozess 14 °C während der Sommermonate nicht überschreiten. Um möglichst hohe Energieeffizienz zu erzielen und eine ganzjährige Beheizung beziehungsweise Kühlung zu vermeiden, sollte das Lager natürlich konditioniert werden: Durch explizite Kopplung des Gärlagers mit dem angrenzenden Erdreich wurde dessen Pufferwirkung über ungedämmte erdberührte Wand‐ und Bodenbauteile aktiviert. Auch das Lagergut selbst wurde als thermische Speichermasse in der Auslegung berücksichtigt. Gleichzeitig wurde die verbliebene thermische Gebäudehülle dahingehend optimiert, dass die auftretenden Wärmegewinne und Wärmeverluste zur Außenluft auf ein Minimum reduziert sind. Der Nachweis der Gebrauchstauglichkeit erfolgte mittels gekoppelter transienter thermischer Gebäudesimulation. Es konnte gezeigt werden, dass – selbst unter Annahme erhöhter Außenluft‐ und Erdreichtemperaturen aufgrund des Klimawandels – bei Ausführung von Außenwänden und Dächern in höchster thermischer Qualität auf eine aktive Konditionierung des Lagers vollständig verzichtet werden kann.
Systematic review of clinical prediction models for survival after surgery for resectable pancreatic cancer
Authors: Strijker M , Chen J W , Mungroop T H , Jamieson N B , van Eijck C H , Steyerberg E W , Wilmink J W , Groot Koerkamp B , van Laarhoven H W , Besselink M G
Published: February 2019

Background

As more therapeutic options for pancreatic cancer are becoming available, there is a need to improve outcome prediction to support shared decision-making. A systematic evaluation of prediction models in resectable pancreatic cancer is lacking.

Methods

This systematic review followed the CHARMS and PRISMA guidelines. PubMed, Embase and Cochrane Library databases were searched up to 11 October 2017. Studies reporting development or validation of models predicting survival in resectable pancreatic cancer were included. Models without performance measures, reviews, abstracts or more than 10 per cent of patients not undergoing resection in postoperative models were excluded. Studies were appraised critically.

Results

After screening 4403 studies, 22 (44 319 patients) were included. There were 19 model development/update studies and three validation studies, altogether concerning 21 individual models. Two studies were deemed at low risk of bias. Eight models were developed for the preoperative setting and 13 for the postoperative setting. Most frequently included parameters were differentiation grade (11 of 21 models), nodal status (8 of 21) and serum albumin (7 of 21). Treatment-related variables were included in three models. The C-statistic/area under the curve values ranged from 0·57 to 0·90. Based on study design, validation methods and the availability of web-based calculators, two models were identified as the most promising.

Conclusion

Although a large number of prediction models for resectable pancreatic cancer have been reported, most are at high risk of bias and have not been validated externally. This overview of prognostic factors provided practical recommendations that could help in designing easily applicable prediction models to support shared decision-making.
The compatibility of six alkaloids in ermiao pill explored by a comparative pharmacokinetic and network pharmacological study
Authors: Xia Zhengxiang , Lv Lei , Di Xuemei , Xue Jiyang , Gao Zhen , Zhang Guoqing , Zhang Hai
Published: February 2019

Ermiao Pill (EMW), a traditional Chines medicine (TCM), composed of a two‐herb pair, Phellodendri Cortex (PC) and Atractylodis Rhizome (AR), is used for the treatment of pelvic inflammatory disease and inflammatory‐related diseases. However, the underlying mechanism is still unknown. Compatibility plays a crucial role in the complex drugs such as those used in traditional Chinese medicine. We propose a compositive strategy, which integrated pharmacokinetics and network pharmacology to explore the compatibility in EMW. Firstly, a simple, rapid, and selective method based on UPLC–MS/MS was established and validated for simultaneous qualification of six alkaloids in rat plasma, which was used for a comparative pharmacokinetic study of EMW and its constituent herb PC. The concentration–time profiles suggested that AR might reduce the toxicity of some alkaloids in EMW. Secondly, network pharmacology analysis showed that the key protein PTGS2 was targeted by four alkaloids, and that the competition among them might be allevited by AR. Thirdly, molecular docking exhibited interactions between the alkaloids and PTGS2 through H and π–π bonds, and the same residue formed interactions with different alkaloids, which account for the toxicity of these alkaloids, and these were confirmed by the cell viability assay. The combination of pharmacokinetics and network pharmacology clarified the compatibility in EMW.
Using CFD simulations and statistical analysis to correlate oxygen mass transfer coefficient to both geometrical parameters and operating conditions in a stirred‐tank bioreactor
Authors: Amer Momen , Feng Yu , Ramsey Joshua D.
Published: February 2019

Optimization of a bioreactor design can be an especially challenging process. For instance, testing different bioreactor vessel geometries and different impeller and sparger types, locations, and dimensions can lead to an exceedingly large number of configurations and necessary experiments. Computational fluid dynamics (CFD), therefore, has been widely used to model multiphase flow in stirred‐tank bioreactors to minimize the number of optimization experiments. In this study, a multiphase CFD model with population balance equations are used to model gas–liquid mixing, as well as gas bubble distribution, in a 50 L single‐use bioreactor vessel. The vessel is the larger chamber in an early prototype of a multichamber bioreactor for mammalian cell culture. The model results are validated with oxygen mass transfer coefficient (kLa) measurements within the prototype. The validated model is projected to predict the effect of using ring or pipe spargers of different sizes and the effect of varying the impeller diameter on kLa. The simulations show that ring spargers result in a superior kLa compared to pipe spargers, with an optimum sparger‐to‐impeller diameter ratio of 0.8. In addition, larger impellers are shown to improve kLa. A correlation of kLa is presented as a function of both the reactor geometry (i.e., sparger‐to‐impeller diameter ratio and impeller‐to‐vessel diameter ratio) and operating conditions (i.e., Reynolds number and gas flow rate). The resulting correlation can be used to predict kLa in a bioreactor and to optimize its design, geometry, and operating conditions.
Surfers' knots in the anterior chest
Authors: Baba Akira , Okuyama Yumi , Yakabe Hiroyuki , Yamazoe Shinji , Kobashi Yuko , Mogami Takuji
Published: February 2019

Key Clinical Message

A history of frequent surfing can be a key finding when a patient comes in with subcutaneous lesions on bilateral anterior lower chest. MR imaging could lead to the diagnosis with its characteristic finding for collagenous mass lesions, though most cases do not require imaging unless with atypical presentation. This enables clinicians to avoid unnecessary invasive procedures.
Colorimetric Methods for Determining Fe, V, and Ni Contents in Coke and Anodes
Authors: Sun Hang , Kocaefe Duygu , Bhattacharyay Dipankar , Kocaefe Yasar , Côté Jules , Coulombe Patrick
Published: February 2019

Prebaked carbon anodes are used in the electrolytic production of aluminum. They are made of petroleum coke, butts, recycled anodes, and coal tar pitch. The anode quality, which depends on the raw material quality and the production conditions, has an important impact on the cell performance. Metallic impurities (V, Ni, and Fe) found in cokes and anodes increase the carbon consumption by catalyzing the air and CO2 reactivities. In turn, this increases the production cost, energy consumption, and the emission of greenhouse gases. The current methods for detecting the metallic impurities in carbon are time consuming and require intensive sample preparation, skilled personnel, and costly reagents. In this work, simple, rapid, and effective tools were developed using colorimetric methods.
Two‐Step Structure Phase Transition, Dielectric Anomalies, and Thermochromic Luminescence Behavior in a Direct Band Gap 2D Corrugated Layer Lead Chloride Hybrid of [(CH3)4N]4Pb3Cl10
Authors: Xue Chen , Wang Shu , Liu Wen‐Long , Ren Xiao‐Ming
Published: February 2019

A direct band gap 2D corrugated layer lead chloride hybrid, [(CH3)4N]4Pb3Cl10 (1), shows analogous topology to the {Mg3F104−}∞ layer in Cs4Mg3F10, and with the (CH3)4N+ cations locating in the inorganic layer voids and between the interlayers. Two reversible structural phase transitions occur in 1 at 225/210 K and 328/325 K upon heating/cooling, respectively. On going from the low‐ to intermediate‐temperature phase, the space group changes from P21/c to Cmca, and the crystallographic axis perpendicular to the layers is doubled with the order–disorder transformation of (CH3)4N+ cations between the interlayers. The intermediate‐ and high‐temperature phases are isomorphic with similar cell parameters and packing structure; their main difference concerns the disorder degree of the (CH3)4N+ cations between the interlayers. The two‐step structural phase transitions lead to dielectric anomalies around the corresponding Tc. Interestingly, 1 shows multiband emission, originating from the recombination of exciton and emission of defects. Moreover, 1 exhibits divergent thermochromic luminescent features around the Tc on the intermediate to low temperature transition.
Reduction of Phosphine Oxide by Using Chlorination Reagents and Dihydrogen: DFT Mechanistic Insights
Authors: Zhu Hui , Qu Zheng‐Wang , Grimme Stefan
Published: February 2019

Extensive DFT calculations provide detailed mechanistic insights into the metal‐free reduction of phosphine oxide Ph3P=O by using chlorination reagents O=CClX (X=COCl, Cl, OCCl3 and Ph) and H2. Fast electrophilic attack to the P=O group oxygen atom is favored by exergonic CO2 release to form phosphonium Ph3PCl+ and chloride Cl−, which may slowly cleave H2 by an unstable HPh3PCl complex yielding Ph3PH+ and Cl− ions in solution. Moderate heating is required to accelerate the slow H2‐activation step and to eliminate HCl to form phosphine Ph3P instead of Ph3PH+Cl− salt as the desired product. Though partially quenched by Ph3P (and reactant Ph3P=O if present), borane B(2,6‐F2C6H3)3 can be still combined with Cl− and Ph3P as reactive frustrated Lewis pair (FLP) catalysts.
Inside Cover: Palladium‐Catalyzed Asymmetric Dihydroxylation of 1,3‐Dienes with Catechols (Chin. J. Chem. 3/2019)
Authors: Fan Tao , Shen Hong‐Cheng , Han Zhi‐Yong , Gong Liu‐Zhu
Published: February 2019

The inside cover picture shows a palladium‐catalyzed asymmetric dihydroxylation of 1,3‐dienes with catechols utilizing chiral pyridinebis(oxazoline) ligand. The reaction is proposed to proceed via a cascade Wacker‐type hydroxypalladation/asymmetric allylation process. This methodology provides a direct and straightforward synthesis to prepare chiral 2‐substituted 1,4‐benzodioxane motifs in moderate to good yield and enantioselectivity from readily available starting materials. More details are discussed in the article by Gong et al. on page 226–232.

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On Ancient Solutions of the Heat Equation
Authors: Lin Fanghua , Zhang Q. S.
Published: February 2019

An explicit representation formula with Martin boundary for all positive ancient solutions of the heat equation in the euclidean case is found. In the Riemannian case with nonnegative Ricci curvature, a similar but less explicit formula is also found. Here it is proven that any positive ancient solution is the standard Laplace transform of positive solutions of the family of elliptic operators Δ – s with s > 0. Further relaxation of the curvature assumption is also possible. It is also shown that the linear space of ancient solutions of polynomial growth has finite dimension and these solutions are polynomials in time. © 2018 the Authors. Communications on Pure and Applied Mathematics is published by the Courant Institute of Mathematical Sciences and Wiley Periodicals, Inc.