bluuebunny/crossref_metadata_2025 huggingface dataset:
The Wrong Side of History
Authors: Cedeño N. M. ,   After Dinner Conversation
Published: October 2021

Is it appropriate to hold politicians accountable for their past votes, their past actions, and their past opinions, even if they are not reflective of them today? In this work of philosophical short story fiction, Senator McCoy is 130 years old and is considered a "national treasure" for his nearly century of public service. Shortly before his retirement he is confronted by a member of an extremist organization (that supports eugenics) who have found evidence of a paper he published in college where he supports abortion. Given the modern political climate where every person is needed to build society, this information would forever stain his legacy. Senator McCoy hires a "fixer" to find and destroy the source material and preserve his legacy. However, things go wrong and the would-be blackmailer crashes the Senators party in an attempt to expose him. The Senator is nearly killed, but is finally able to enjoy an untarnished retirement legacy free from the truth of his past.
Why We Should Stop Fethishing Democracy
Authors: Ahlstrom-Vij Kristoffer ,   Philosophy Documentation Center
Published: October 2021

Democracy is in trouble, and it is democracy’s own fault—that is Robert Talisse’s intriguing contention is his recent book, Overdoing Democracy: Why We Must Put Politics in its Place (2019). What gets democracy into trouble, according to Talisse, is the idea that a democratic form of government is intrinsically valuable, which in turn entails a deliberative conception of democracy that, in combination with the social-psychological fact of social sorting, leads to rampant polarization. According to Talisse, we therefore need to put democracy in its place by resisting the expansive view of the scope of democracy and making room for non-political spaces of interaction, in which we can form civic friendships. However, in what follows, I argue that what Talisse has actually provided is an excellent reason for rejecting rather than merely mitigating the detrimental effects of the idea that democracy is intrinsically valuable. Specifically, we ought to stop fetishizing democracy and instead embrace an instrumentalist view of democracy as a social practice that is instituted and maintained for purposes external to itself. Once we do this, democracy no longer needs saving from itself.
Introspective Distinguishability
Authors: Schönbaumsfeld Genia ,   Philosophy Documentation Center
Published: October 2021

It is generally thought that if introspective distinguishability (ID) were available, it would provide an answer to scepticism about perceptual knowledge by enabling us to tell the difference between a good case perceptual experience and a bad kind. This paper challenges this common assumption by showing that even if ID were available, it would not advance our case against scepticism. The conclusion to draw from this result is not to concede to scepticism, however, but rather to give up on the idea that ID is required for knowledge. For if perception with ID turns out to get us no further than perception without ID, then the rational thing to do is to realize that the putative presence (or absence) of ID is a red herring in the debate about scepticism and can make no difference to the question of whether or not perceptual knowledge is possible.
Impact of COVID-19 induced lockdown on physical activity and sedentary behavior among university students: A systematic review
Authors: Rivera Paola Andrea , Nys Bojan Luc , Fiestas Fabián
Published: October 2021

Background The COVID-19 pandemic has entailed a significant socio-economic impact on various layers of the population. In many countries, attempts to control viral dissemination involved lockdown measures that limited citizens' overall mobility and professional and leisure activities. Objective This systematic review investigates the impact of COVID-19-induced lockdowns on university student physical activity and sedentary behav-ior, as these relate to physical and mental well-being. Methods Data was collected through PubMed/MEDLINE, Embase, SCOPUS, and APA PsycInfo databases until January 2021. Results Seven studies conducted in five different countries (United States, Spain, Italy, China, and United Kingdom) were included in the final review. Overall, most studies reported a significant decrease in mild physical activity (i.e., walking) among undergraduate students but not among graduate students. Consistently, most studies reported a significant increase in sedentary time (i.e., sitting time on weekdays) in undergraduate students but not in graduate students. We observed that students who were more sedentary previous to lockdown, increased or did not change their moderate and/or vigorous physical activity. In contrast, those who were less sedentary previous to lockdown decreased their moderate and/or vigorous physical activity. Conclusions COVID 19 induced lockdowns appear to have negatively affected walking and sedentary behavior among undergraduate students but not among graduate students. Our results highlight the importance of promoting the World Health Organization recommendations for physical activity and sedentary behavior among university students to improve health outcomes.
Dynamics of non-Hermitian local topological marker
Authors: Sun Kong-Hao , Yi Wei ,   CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei 230026, China
Published: October 2021

Topological invariants of non-Hermitian topological systems can be captured by local topological markers defined on the biorthogonal basis. However, unlike the scenario of Hermitian systems, the dynamics of non-Hermitian local topological marker has not yet received much attention so far.

Here in this work, we study the dynamic features of local topological markers in non-Hermitian topological systems. In particular, we focus on the propagation of non-Hermitian topological markers in quench dynamics. We find that for the dynamics with topologically distinct pre- and post-quench Hamiltonians, a flow of local topological markers emerges in the bulk, with its propagation speed related to the maximum group velocity. Taking three different non-Hermitian topological models for example, we numerically calculate the propagation speed, and demonstrate that a simple universal relation between the propagation speed and group velocity does not exist, which is unlike the scenarios in previously studied Hermitian systems. Our results reveal the complexity of the local-topological-marker dynamics in non-Hermitian settings, and would stimulate further study on the matter.
Utility of polygenic embryo screening for disease depends on the selection strategy
Authors: Lencz Todd , Backenroth Daniel , Granot-Hershkovitz Einat , Green Adam , Gettler Kyle , Cho Judy H , Weissbrod Omer , Zuk Or , Carmi Shai
Published: October 2021

Polygenic risk scores (PRSs) have been offered since 2019 to screen in vitro fertilization embryos for genetic liability to adult diseases, despite a lack of comprehensive modeling of expected outcomes. Here we predict, based on the liability threshold model, the expected reduction in complex disease risk following polygenic embryo screening for a single disease. A strong determinant of the potential utility of such screening is the selection strategy, a factor that has not been previously studied. When only embryos with a very high PRS are excluded, the achieved risk reduction is minimal. In contrast, selecting the embryo with the lowest PRS can lead to substantial relative risk reductions, given a sufficient number of viable embryos. We systematically examine the impact of several factors on the utility of screening, including: variance explained by the PRS, number of embryos, disease prevalence, parental PRSs, and parental disease status. We consider both relative and absolute risk reductions, as well as population-averaged and per-couple risk reductions, and also examine the risk of pleiotropic effects. Finally, we confirm our theoretical predictions by simulating ‘virtual’ couples and offspring based on real genomes from schizophrenia and Crohn’s disease case-control studies. We discuss the assumptions and limitations of our model, as well as the potential emerging ethical concerns.
Linking functional and molecular mechanisms of host resilience to malaria infection
Authors: Kamiya Tsukushi , Davis Nicole M , Greischar Megan A , Schneider David , Mideo Nicole
Published: October 2021

It remains challenging to understand why some hosts suffer severe illnesses, while others are unscathed by the same infection. We fitted a mathematical model to longitudinal measurements of parasite and red blood cell density in murine hosts from diverse genetic backgrounds to identify aspects of within-host interactions that explain variation in host resilience and survival during acute malaria infection. Among eight mouse strains that collectively span 90% of the common genetic diversity of laboratory mice, we found that high host mortality was associated with either weak parasite clearance, or a strong, yet imprecise response that inadvertently removes uninfected cells in excess. Subsequent cross-sectional cytokine assays revealed that the two distinct functional mechanisms of poor survival were underpinned by low expression of either pro- or anti-inflammatory cytokines, respectively. By combining mathematical modelling and molecular immunology assays, our study uncovered proximate mechanisms of diverse infection outcomes across multiple host strains and biological scales.
Prevalence of non-specific chronic low-back pain and risk factors among male soldiers in Saudi Arabia
Authors: Sidiq Mohammad , Alenazi Wadha , Kashoo Faizan Z. , Qasim Mohammad , Lopez Marisia Paz , Ahmad Mehrunnisha , Mani Suresh , Shaphe Mohammad Abu , Khodairi Omaymah , Almutairi Abdulqader , Mir Shabir Ahmad
Published: October 2021

Background

Non-specific chronic low back pain (NSCLBP) is the most common musculoskeletal disorder affecting health and work among the military population. NSCLBP is a complex disorder with several risk factors contributing to its occurrence. Therefore, the objective of our study was to estimate the prevalence and contribution of risk factors towards NSCLBP among male soldiers in Saudi Arabia.

Methods

A cross-sectional study was conducted from March 2020 to January 2021 among the military personnel at Hafar Al-Batin military base, Saudi Arabia. The entire population (n = 62, 000) at the military base were invited to participate in the study. The participants were invited to participate in the study either through direct referral from in-patient and out-patient departments of the military hospital or by invitation through pamphlets, email, and advertisement across the offices and residential areas. Soldiers reporting lower back pain for at least 12 weeks were screened for inclusion criteria at the physical therapy department of the military hospital. Inclusion criteria included pain or discomfort originating from the lower back without any known spinal diseases. Participants with a systemic inflammatory disorder, trauma, neurological symptoms, and recent spinal surgery were excluded. All eligible participants were assessed for demographic variables and risk factors and complete the Rolland Morris Disability Questionnaire and WHO-Five Well-Being Index.

Results

This study identified a 46.3% prevalence of pain originating from the spine with a 2.7% prevalence of NSCLBP. Spearman’s rho correlation between the severity of disability due to NSCLBP was strongly associated with age (rs= 0.834,p < 0.01), quality of sleep (rs= 0.790,p < 0.01), body mass index (BMI) (rs= 0.617,p < 0.01), smoking (rs= 0.520,p < 0.01), co-morbidity (rs= 0.357,p < 0.01), but not with the level of physical activity (rs= 0.044,p = 0.07).

Conclusion

There was a high prevalence of pain originating from the spine among male Saudi soldiers with a relatively low prevalence of NSCLBP. However, the prevalence of disability due to NSCLBP was strongly associated with age, sleep quality, BMI, smoking habit, and co-morbidity.
A study on Economic Analysis of Organic Coconut Cultivation in Coimbatore District
Authors: Parthiban J. J. , Anjugam M.
Published: October 2021

The study analyses the economics of coconut production under organic farming in Coimbatore District of Tamil Nadu. Participatory Guarantee Scheme (PGS) was studied in accordance to how farmers get their organic farming certification under PKVY scheme in Tamil Nadu. The estimated variable cost was Rs. 43,025/ha. The total cost of cultivation was Rs.82,216/ha. The net income over operational cost was Rs.2,95,888/ha and net income over total cost was Rs.2,56,697/ha. Total yield was increasingly responsive with higher application of farm yard manure and bio- fertilizers. Results of scale efficiency shows majority of the farms were operating in optimum return to scale. Inadequate supply of labour and inadequate market for organic products poses as major constraints to organic coconut farming in the area of study.

Aim: The purpose of the study was to find out the profitability level and responsiveness of yield with input application of organic farming through Participatory Guarantee Scheme (PGS) and how farmers actively involved in organic farming to conserve natural resources.

Design of Study and Methodology: The study was conducted in Coimbatore district of Tamil Nadu (2020) with 60 sample respondents. Purposive sampling was adopted for the study and two blocks were selected based on the leading operator of PGS scheme. The data were collected through well-structured interview schedule which was prepared through pre-tested survey. The analytical methods followed in the study included cost and returns estimation, resource use efficiency and data envelopment analysis to reveal the exact scenario of organic farming practices.

Findings of the study:

The study showed about

Organic coconut is found to be one of the most important and sustainable crop options.

Estimates of Resource Use Efficiency show that coconut yield was relatively higher with use of farm yard manure and bio- fertilizers, compared to all other organic inputs

Nearly, 32.5 per cent of the farms considered under study were found to be operating in constant returns to scale.

The major marketing constraint faced by the sample farmers through organic farming was inadequate supply of labour and price fluctuations of coconut.
Academic Stress and Coping Strategies among Postgraduate Students: Comparative Study of Universities in Imo State, Nigeria
Authors: Ezelote J. C. , Eleanor Asuzu , Judith Obi , Joy Mbachu
Published: October 2021

Aims: The study aimed to identify and compare the prevalence of stress among postgraduate students in Imo State University (IMSU)and Federal University of Technology, Owerri(FUTO)using General Health Questionnaire-12 (GHQ-12), to identify and compare their sources of academic stress using Postgraduate Stressor Questionnaire(PSQ); and to identify and compare the measures the students were using to cope with stress using Cope inventory.

Sample: All the postgraduate students admitted in 2015/2016 session in FUTO and IMSU were sampled for this study, with 10% and 8% attrition rates in IMSU and FUTO respectively.

Study Design: This is a comparative cross sectional study between the postgraduate students in IMSU and FUTO.

Place and Duration of Study: Imo State University (IMSU) and Federal University of Technology, Owerri (FUTO), between August 2017 to November 2017.

Methodology: All the postgraduate students admitted in 2015/2016 session in FUTO and IMSU were used for this study (121 were from IMSU while 832 were from FUTO). PSQ, GHQ-12 and COPE Inventory were for data collection used to collect data. Chi square was used to test the hypotheses and the significance level was p≤0.05.

Results: It was observed that 79% of FUTO students were under eustress while 36% of those at IMSU were under eustress. Majority (80%) of FUTO respondents were using positive coping strategies compared to 36% of IMSU students using positive coping strategies. There was significant difference in the prevalence of stress and coping strategies among the students in the two universities (<0.001*).

Conclusion: Academic stress leads to many physiological and mental illnesses. It results from the stressful situations that persist over time and produces negative health outcomes. Postgraduate students in Nigeria face a number of pressures that are distinct from the stresses that undergraduates face. If it is not managed with positive coping strategies it will leads to wearing effects on people.
Methods for the Detection and Quantification of Micro and Nanoplastics- A Review
Authors: Priyanka S. , Pallavi G. A. , Swathi Nayak N. , D. Ashita Jawali
Published: October 2021

Over the past 35 years, synthetic or semi-synthetic polymers called “plastics” have been widely used across multiple fields due to their low cost, versatility, durability. Plastics have proved to be a boon to mankind. However, overuse of non- biodegradable plastics comes with its own downsides. Despite constant efforts to reuse and recycle plastics, these polymers substantially contribute towards the accumulation of debris hazardous to the environment. Plastic materials are slowly broken into fragments of micro- and nano plastics due to aging and weathering. Micro- and nano plastics were found capable of entering the food chain and hence are viewed as threats. This review paper revolves around methods used for the detection and quantification of micro- and nano plastics. Detection of micro- and nano plastics using methods like Raman spectroscopy, Infrared Spectroscopy, SERS, MALDI-TOF, and machine learning approaches are discussed here. The research efforts carried out in this article aims to further facilitate the R&D initiatives of Jozbiz Technologies.
Prevalence and Associated Risk Factors of Hypertension among Adults (40 Years and Above) in the Tano North District of the Ahafo Region, Ghana
Authors: Sumaila Issah , Asumah Mubarick Nungbaso , Dassah Rosaline Bierema
Published: October 2021

Introduction: Increased prevalence of hypertension (HTN) has been attributed to commonly known risk factors such as obesity, low level of nutritional knowledge, lack of exercise, alcohol intake, and tobacco use.

Objective: The objective of this study is to determine the prevalence, and associated risk factors of hypertension among residents of the Yamfo community in the Ahafo Region of Ghana.

Methods:  A community-based cross-sectional study of 174 participants aged ≥40 years were enrolled using simple random sampling. A structured questionnaire was used to elicit information on sociodemographic characteristics, behavioural/lifestyle risk factors and knowledge of hypertension. Data was analysed using SPSS version 23.

Results: Prevalence of hypertension was 63.2% (95% CI: 55.7–70.1) in adults 40 years and above. Risk factors that were significantly associated with hypertension were lack of physical activity (p=0.030), alcohol consumption (p=0.001), consumption of meals prepared with oil (p=0.016), reduced frequency of fruit consumption (p=0.008) and reduced frequency of vegetable consumption (p<0.001). Increasing age (aOR,1.9; 95%CI (1.3-2.4); p=.049), physical activity (cOR,2.12, 95% CI (1.07-4.21), p=.032), alcohol consumption (aOR, 57.03; 95% C1 (4.48-726.59); p=.002), and knowledge on the cause of hypeternsion (aOR, 3.41; 95% CI (1.93-5.17); p=.032) were observed as determinants of hypertension.

Conclusion: Majority of the study participants were hypertensive, with the majority of them having knowledge on risk factors of hypertension. Majority of participants had the opinion that hypertension is inevitable, because it comes with old age. Enough (Intensive) education concerning hypertension could be extended to the community, about the different, but equally relevant risk factors of hypertension, such as smoking, alcohol consumption, reduced fruit and vegetable consumption and inappropriate diet. This could be achieved by organizing outreach programs by the community health workers in places like markets and churches in order to remit the elderly that they can still be healthy in old age, and at schools and on social media to inculcate positive health behavior in the youth.
Nigeria’s Greenhouse Gas Emissions: Estimations Based on the 5th Assessment Report
Authors: Ezeokoro C. E. , Leton T. G , Momoh Y.
Published: October 2021

The lack of GHG emissions inventory and absence of standardized estimation methods necessitated this study. American Petroleum Institute’s method of Greenhouse gas estimation methods combined with the global warming potential in the 5th assessment report and Nigeria’s unique gas composition were used to estimate volume of GHG’s resulting from gas flaring in Nigeria between 1965 to 2020, as reported by NNPC. The findings show the total CO2, CH4, N2O and GHG emission between 1965 to 2020 were 1.86*109 tons, 3.3*108 tons, 5.76*109 tons, and 7.94*109 tons respectively. In the 56 years under review, the gas produced was estimated at 2,14*106 MCM, while 9.44*105 MCM of the gas was flared, accounting for 44% of the total gas produced over the years. Overall, the study revealed a striking cause for concern due to the predicted continuous increasing amount of gas flaring and release of greenhouse gas emissions which could have significant effects on the environment. Curbing gas flaring: increased gas utilization for domestic and export uses and standardization of GHG estimation methods were recommended.
Egyptian Mathematics Disclosure
Authors: Denis Olivier
Published: October 2021

Some fundamental mathematical researches have been carried out about mathematical certainties based on ancient Egyptian mathematical sources and their problems following ancient Egyptian Wisdom set of knowledge building the new scientific paradigm following the rediscovery of the true value of PI and following the new approach of Global Dimensional Mathematics [1].

Some fundamental mathematical researches on the foundations of Egyptian mathematics covering the mathematical problem of The Akhmin wooden tablets [2], the tenth and the fourteenth problem of The Moscow Mathematical Papyrus [3] as well as the forty-first and fiftieth problem from The Rhind Mathematical Papyrus [3] have been carried out, without forgotten, the resolution of the fundamental question of the quadrature of the circle which is now effective.

In the disclosure of Egyptian mathematics, the new approach to fundamental mathematical notions is established, adding the cornerstone to building the core of the new approach to Egyptian mathematics, mathematics and science in general.

The Egyptian mathematics disclosure solves, following the Egyptian approach to mathematics and following ancient Egyptian Wisdom set of knowledge, unsolved ancient Egyptian mathematical problems, such as finding the complete solution and decoding the glyph of the eye of Horus, as well as the problem of the truncated pyramid which has found a solution like the half basket problem found one. The question of the quadrature of the circle shatters the mathematical conceptions with all the consequences that we can only begin to understand.

The Egyptian mathematics disclosure forms the basis for building the new scientific approach based on ancestral Egyptian mathematical problems, the true rediscovered value of PI and the new original Global Dimensional Mathematics opening up a still unknown perspective on the world of science in general.
Role of Jundi-Shapur in Streamlining of ILM-E-TIBB (Medicine)
Authors: I. Munshi Younis , Ansari Masihuzzaman
Published: October 2021

People have always felt the need to seek the knowledge from time immemorial. Be it the knowledge of religion or science or philosophy or astronomy. The knowledge of medicine was confined to cultures till 4th century AD. Every subcontinent and every civilization was having its own traditions to treat the diseases, e.g. Ayurved in India, Egyptian traditional medicine in Egypt, Chinese traditional medicine in China, Iranian Traditional medicine in Iran etc etc.

It was during the 5th century AD when Roman Empire cracked down on its seminaries and the intellectuals were forced to leave the country. Those intellectuals were given refuge by Persian Empire where in a city was established with ultimate autonomy under Khusro, Jundi-Shapur became a prosperous metropolis, refuge, and melting pot for intellectuals from many regions. Shapur II (309-379 A.D.) is credited for conceiving and establishing the nucleus of the university in the latter part of the fourth century. The closing of the Athenian school by the Byzantine Emperor Justinian (AD 539) also drove many leaned Greek physicians to Jundi-Shapur. This was the start of the integration of different traditional medicine of different civilizations. This formed the basis of what we see today as modern medicine. In this way JundiShapur has important role in the development of Medical knowledge and it remained in the leading role until 9th Century AD.
Knowledge of Cervical Cancer Screening among Women in Rural Areas
Authors: Kannan K. , Rajini S. , Sundari P. Padma , Ramraj D. , Nivethidha A. N. , Saranya R. E.
Published: October 2021

Introduction: Cervical cancer is the most preventable and successfully treatable form of cancer, as long as it is detected early and managed effectively. Cancers diagnosed in late stages can also be controlled with appropriate treatment and palliative care. Screening is therefore an important tool in detecting cancer. The objective of this research is to find about the depth of knowledge about cervical cancer among rural women. This is a cross – sectional study done in rural areas of Pondicherry (Koodapakkam and Katterikuppam) (around 10 Km). Our subjects were patients and attenders attending the PHC OPD in between January and March 2021. Women attending OPDs of PHC in and around Koodapakkam and Katterikuppam who are > 15 years of age were the study sample excluding pregnant women, lactating women, mentally ill women and post hysterectomy patients with sample size of 300 using a questionnaire. Our study Signifies that among 277 Hindu women, 68.59% were aware of Cervical cancer screening. Among 12 Muslims 75% were aware of Cervical cancer screening. Among 11 women following Christianity 63.63% were aware of cervical cancer screening. This proves that there is no significant association between religion and awareness. (p=0.43) In our study, among 67 illiterates, 64.17% were aware of Cervical cancer screening. Among 81 women with primary school education ,65.43 % were aware of Cervical cancer screening. Among 57 women who went to high school 77.19% were aware of Cervical cancer screening. Among 38 women with higher secondary education, 68.42% were aware of Cervical cancer screening. among 49 graduates, 71.42% were aware of Cervical cancer screening. Among 8 post graduates 37.5% were not aware of Cervical cancer screening. There is association between education and awareness. (p=0.001). Totally, among 208 women under 45 years of age, 73.07% were aware of Cervical cancer screening and among 92 women more than 45 years of age 58.69% were aware of Cervical cancer screening. There is significant association between age and awareness (p=0.005).
Mechanical Performance Analysis of Cast Al−Si Alloy Cylinder Head Using Small Specimens
Authors: Ren Peirong , Zhao Chengzhang , Huang Weiqing , Zuo Zhengxing , Yan Kangjie , Li Dongwei , Zhou Haitao
Published: October 2021

The mechanical properties’ variation of the cylinder head caused by heterogeneities of microfeatures is systematically investigated by metallography measurements, X‐ray computed tomography, tensile and fatigue tests using small specimens, and fracture surface analysis. The results show that the microstructure and defect characteristics of the cylinder head exhibit high spatial heterogeneity, and the local mechanical performance is closely related to the microfeatures. The tensile and hardness properties of the top plate and flame plate are optimum, followed by the connecting wall, and the walls between inlet/exhaust and water jacket exhibit the worst properties. The difference in yield stress and hardness at different positions is relatively small, which has a close correlation with secondary dendrite arm spacing (SDAS), whereas the difference in ultimate tensile stress and elongation is relatively large. The fatigue life of the walls between inlet/exhaust and water jacket is significantly lower than that of the other positions. The porosity and SDAS are the two key parameters determining the fatigue strength of the alloy, and the relationship between fatigue life and fracture surface porosity and SDAS is established, which can predict well the fatigue life within a feasible scatter band.
Bacterial Materials: Applications of Natural and Modified Biofilms
Authors: Hayta Elif N. , Ertelt Marvin J. , Kretschmer Martin , Lieleg Oliver
Published: October 2021

Over millennia, bacteria have developed clever strategies to build biopolymer‐based communities in which they can survive even extremely challenging conditions. Such bacterial biofilms come with a broad range of fascinating material properties that—in settings such as medicine, food production, or other areas of industry—make it difficult to remove or inactivate them: they can stick to many surfaces, repel water and oils, and can even transport electrons. Inspired by the outstanding versatility and sturdiness of such bacterial biofilms, material scientists have set out to harness those properties and to create bacterial materials for different applications. However, as the range of technological applications employing biofilms keeps expanding, improved material properties or broader functionalities are desired. Here, such attempts where materials with improved properties were created by making use of either natural or modified bacterial biofilms are reviewed. The areas in which those bacterial materials may be used range from agriculture and (environmental) biotechnology over biomedical and electrical engineering to construction engineering.
Probing Ultrafast Dynamics of Ferroelectrics by Time‐Resolved Pump‐Probe Spectroscopy
Authors: Zhang Yuan , Dai Junfeng , Zhong Xiangli , Zhang Dongwen , Zhong Gaokuo , Li Jiangyu
Published: October 2021

Ferroelectric materials have been a key research topic owing to their wide variety of modern electronic and photonic applications. For the quick exploration of higher operating speed, smaller size, and superior efficiencies of novel ferroelectric devices, the ultrafast dynamics of ferroelectrics that directly reflect their respond time and lifetimes have drawn considerable attention. Driven by time‐resolved pump‐probe spectroscopy that allows for probing, controlling, and modulating dynamic processes of ferroelectrics in real‐time, much research efforts have been made to understand and exploit the ultrafast dynamics of ferroelectric. Herein, the current state of ultrafast dynamic features of ferroelectrics tracked by time‐resolved pump‐probe spectroscopy is reviewed, which includes ferroelectrics order parameters of polarization, lattice, spin, electronic excitation, and their coupling. Several potential perspectives and possible further applications combining ultrafast pump‐probe spectroscopy and ferroelectrics are also presented. This review offers a clear guidance of ultrafast dynamics of ferroelectric orders, which may promote the rapid development of next‐generation devices.
Insight into Carbocation‐Induced Noncovalent Interactions in the Methanol‐to‐Olefins Reaction over ZSM‐5 Zeolite by Solid‐State NMR Spectroscopy
Authors: Wang Chao , Chu Yueying , Hu Min , Cai Wenjin , Wang Qiang , Qi Guodong , Li Shenhui , Xu Jun , Deng Feng
Published: October 2021

Carbocations such as cyclic carbenium ions are important intermediates in the zeolite‐catalyzed methanol‐to‐olefins (MTO) reaction. The MTO reaction propagates through a complex hydrocarbon pool process. Understanding the carbocation‐involved hydrocarbon pool reaction on a molecular level still remains challenging. Here we show that electron‐deficient cyclopentenyl cations stabilized in ZSM‐5 zeolite are able to capture the alkanes, methanol, and olefins produced during MTO reaction via noncovalent interactions. Intermolecular spatial proximities/interactions are identified by using two‐dimensional 13C–13C correlation solid‐state NMR spectroscopy. Combined NMR experiments and theoretical analysis suggests that in addition to the dispersion and CH/π interactions, the multiple functional groups in the cyclopentenyl cations produce strong attractive force via cation‐induced dipole, cation–dipole and cation–π interactions. These carbocation‐induced noncovalent interactions modulate the product selectivity of hydrocarbon pool reaction.
Sterically Wrapped Multiple Resonance Fluorophors for Suppression of Concentration Quenching and Spectrum Broadening
Authors: Zhang Yuewei , Wei Jinbei , Zhang Dongdong , Yin Chen , Li Guomeng , Liu Ziyang , Jia Xiaoqin , Qiao Juan , Duan Lian
Published: October 2021

Multiple resonance (MR) emitters are promising for highly efficient organic light‐emitting diodes (OLEDs) with narrowband emission; however, they still face intractable challenges with concentration‐caused emission quenching, exciton annihilation, and spectral broadening. In this study, sterically wrapped MR dopants with a fluorescent MR core sandwiched by bulk substituents were developed to address the intractable challenges by reducing intermolecular interactions. Consequently, high photo‐luminance quantum yields of ≥90 % and small full width at half maximums (FWHMs) of ≤25 nm over a wide range of dopant concentrations (1–20 wt %) were recorded. In addition, we demonstrated that the sandwiched MR emitter can effectively suppress Dexter interaction when doped in a thermally activated delayed fluorescence sensitizer, eliminating exciton loss through dopant triplet. Within the above dopant concentration range, the optimal emitter realizes remarkably high maximum external quantum efficiencies of 36.3–37.2 %, identical small FWHMs of 24 nm, and alleviated efficiency roll‐offs in OLEDs.
Carboxylation of a Palladacycle Formed via C(sp3)−H Activation: Theory‐Driven Reaction Design
Authors: Kanna Wataru , Harabuchi Yu , Takano Hideaki , Hayashi Hiroki , Maeda Satoshi , Mita Tsuyoshi
Published: October 2021

Theory‐driven organic synthesis is a powerful tool for developing new organic transformations. A palladacycle(II), generated from 8‐methylquinoline via C(sp3)−H activation, is frequently featured in the scientific literature, albeit that the reactivity toward CO2, an abundant, inexpensive, and non‐toxic chemical, remains elusive. We have theoretically discovered potential carboxylation pathways using the artificial force induced reaction (AFIR) method, a density‐functional‐theory (DFT)‐based automated reaction path search method. The thus obtained results suggest that the reduction of Pd(II) to Pd(I) is key to promote the insertion of CO2. Based on these computational findings, we employed various one‐electron reductants, such as Cp*2Co, a photoredox catalyst under blue LED irradiation, and reductive electrolysis ((+)Mg/(−)Pt), which afforded the desired carboxylated products in high yields. After screening phosphine ligands under photoredox conditions, we discovered that bidentate ligands such as dppe promoted this carboxylation efficiently, which was rationally interpreted in terms of the redox potential of the Pd(II)‐dppe complex as well as on the grounds of DFT calculations. We are convinced that these results could serve as future guidelines for the development of Pd(II)‐catalyzed C(sp3)−H carboxylation reactions with CO2.
A Free Radical Cyclization Catalyzed by Ruthenium Hydride Species
Authors: Kim Rira , Kwon Kuktae , Lee Hee‐Yoon
Published: October 2021

A photolytically generated ruthenium hydride species catalyzing a free radical cyclization reaction was developed. As the new methodology ensures reproducibility of the free radical reaction of trialkyltin hydrides and a fast hydrogen transfer to the radical intermediates, the methodology provides fast quenching of radical intermediates and thus suppresses rearrangement of radical intermediates before the hydride quench. By offering new reactivity and selectivity to the trialkyltin hydride mediated free radical cyclization reactions, the methodology will find wide range of applications in organic synthesis.
Controllable Modulation of Defects for Layered Double Hydroxide Nanosheets by Altering Intercalation Anions for Efficient Electrooxidation Catalysis
Authors: Lai Tianyi , Wang Jikang , Sun Xiaoliang , Zhao Yufei , Song Yu‐Fei
Published: October 2021

Hydrazine (N2H4) is considered as one of the most potential energy storage materials in liquid fuel cells, as it contains high energy and power density, and the high‐efficiency oxidation of N2H4 in fuel cells has drawn great attention. However, the most used catalysts are expensive noble metal catalysts, thus the development of highly efficient non‐noble metal catalysts is crucial to reduce the cost of hydrazine oxidation in practical industry. Herein, we synthesized a series of CoFe‐layered double hydroxides (CoFe‐LDHs) intercalated with different anions via a simple one‐step co‐precipitation method for the electrooxidation of hydrazine. Through altering the intercalated anions of CoFe‐LDHs, the defects and the electronic structure can be well controlled, and the catalytic performance for the electrooxidation of hydrazine were well promoted by using NO3− intercalated into CoFe‐LDH compared with other anions (like Cl−, BO33−, CO32−). This work developed a series of hydrazine electrooxidation catalysts and established the relationship between the intercalated anions, the fine structure of the catalyst and the electrocatalytic performance.
Antisense Oligonucleotide Modified with Disulfide Units Induces Efficient Exon Skipping in mdx Myotubes through Enhanced Membrane Permeability and Nucleus Internalization
Authors: Hiraoka Haruka , Shu Zhaoma , Tri Le Bao , Masuda Keiko , Nakamoto Kosuke , Fangjie Lyu , Abe Naoko , Hashiya Fumitaka , Kimura Yasuaki , Shimizu Yoshihiro , Veedu Rakesh N. , Abe Hiroshi
Published: October 2021

We have found that antisense oligonucleotides and siRNA molecules modified with repeat structures of disulfide units can be directly introduced into the cytoplasm and exhibit a suppressive effect on gene expression. In this study, we analyzed the mechanism of cellular uptake of these membrane‐permeable oligonucleotides (MPONs). Time‐course analysis by confocal microscopy showed that the uptake of MPONs from the plasma membrane to the cytoplasm reached 50 % of the total uptake in about 5 min. In addition, analysis of the plasma membrane proteins to which MPONs bind, identified several proteins, including voltage‐dependent anion channel. Next, we analyzed the behavior of MPONs in the cell and found them to be abundant in the nucleus as early as 24 h after addition with the amount increasing further after 48 and 72 h. The amount of MPONs was 2.5‐fold higher than that of unmodified oligonucleotides in the nucleus after 72 h. We also designed antisense oligonucleotides and evaluated the effect of MPONs on mRNA exon skipping using DMD model cells; MPONs caused exon skipping with 69 % efficiency after 72 h, which was three times higher than the rate of the control. In summary, the high capacity for intracytoplasmic and nuclear translocation of MPONs is expected to be useful for therapeutic strategies targeting exon skipping.
Reconstruction of Hyper‐Thermostable Ancestral L‐Amino Acid Oxidase to Perform Deracemization to D‐Amino Acids
Authors: Ishida Chiharu , Miyata Ryo , Hasebe Fumihito , Miyata Azusa , Kumazawa Shigenori , Ito Sohei , Nakano Shogo
Published: October 2021

L‐amino acid oxidases (LAAOs) with broad substrate specificity can be used in the deracemization of D,L‐amino acids (D,L‐AAs) to their D‐enantiomers. Hyper‐thermostable LAAO (HTAncLAAO) was designed through a combination of manual sequence data mining and ancestral sequence reconstruction. Soluble expression of HTAncLAAO (>50 mg/L) can be achieved using an E. coli system. HTAncLAAO, which recognizes seven L‐AAs as substrates, exhibits extremely high thermal stability and long‐term stability; the t1/2 value was 95 °C and <5% activity loss after incubation of the enzyme at 30 °C for 1 week. Deracemization could be achieved at 40 °C with a small amount of enzymes compared to previously reported LAAOs. A total of 0.4 mg (2 U) of HTAncLAAO is enough to deracemize three D,L‐AAs at a preparative scale with high enantiomeric excess (>99 % ee, D‐enantiomer). These results suggest that HTAncLAAO is an excellent biocatalyst to perform this deracemization.
Diastereoselective [2+2+1] Hydrative Annulation of Phenol‐Linked 1,6‐Enynes with Acetylenes Through Rhodium Catalysis: A Rapid Access to Cyclopenta[b]benzofuranols
Authors: Nagireddy Attunuri , Dattatri  , Babu Nanubolu Jagadeesh , Sridhar Reddy Maddi
Published: October 2021

An unprecedented [2+2+1] hydrative annulation of 1,6‐enynes with terminal alkynes is achieved using catalytic cationic Rh(I). Thus, a modular assembly of cyclopenta[b]benzofuranols with two consecutive quarternary stereocenters is achieved from readily available alkynes. The reaction is proposed to go through a sequence of 5‐membered rhoda‐cycle formation, regioselective acetylene insertion, 1,5 H‐shift, substrate controlled stereoselective addition of water molecule followed by 1,2‐rhodium migration gave contracted rhoda‐cycle D and reductive elimination. Necessary control/labelling experiments were conducted to gain insight in to the mechanism.
Reactivity of the Bicyclic Amido‐Substituted Silicon(I) Ring Compound Si4{N(SiMe3)Mes}4 with FLP‐Type Character
Authors: Schwedtmann Kevin , Quest Michael , Guddorf Benedikt J. , Keuter Jan , Hepp Alexander , Feldt Milica , Droste Jörn , Hansen Michael Ryan , Lips Felicitas
Published: October 2021

The bicyclic amido‐substituted silicon(I) ring compound Si4{N(SiMe3)Mes}4 2 (Mes=Mesityl=2,4,6‐Me3C6H2) features enhanced zwitterionic character and different reactivity from the analogous compound Si4{N(SiMe3)Dipp}4 1 (Dipp=2,6‐iPr2C6H3) due to the smaller mesityl substituents. In a reaction with the N‐heterocyclic carbene NHC
(1,3,4,5‐tetramethyl‐imidazol‐2‐ylidene), we observe adduct formation to give Si4{N(SiMe3)Mes}4 ⋅ NHC
(3). This adduct reacts further with the Lewis acid BH3 to yield the Lewis acid–base complex Si4{N(SiMe3)Mes}4 ⋅ NHC
 ⋅ BH3 (4). Coordination of AlBr3 to 2 leads to the adduct 5. Calculated proton affinities and fluoride ion affinities reveal highly Lewis basic and very weak Lewis acidic character of the low‐valent silicon atoms in 1 and 2. This is confirmed by protonation of 1 and 2 with Brookharts acid yielding 6 and 7. Reaction with diphenylacetylene only occurs at 111 °C with 2 in toluene and is accompanied by fragmentation of 2 to afford the silacyclopropene 8 and the trisilanorbornadiene species 9.
Thermotriggered Domino‐like Single‐Crystal‐to‐Single‐Crystal Phase Transition from Face‐to‐Edge to Face‐to‐Face Packing of Anthracenes
Authors: Hino Yuto , Hayashi Shotaro
Published: October 2021

Stimuli‐triggered crystal‐to‐crystal and single‐crystal‐to‐single‐crystal (SCSC) transformations have received significant attention in the scientific community. To visualize such phenomenon, controlling the optical properties and the thermodynamic stability of the molecular crystals is a very important research subject. In this report, the selective growth of photoluminescent (PL) 1,8‐bisphenylanthracene polymorphic (cI and cII) and 1,2‐dichloroethane‐inclusion crystals (iC) under various optimized conditions is described. These crystals exhibited unique mechano‐ and thermoresponsive disordering, crystal‐to‐crystal phase transition, and SCSC phase transition. In particular, rapid thermostimulus SCSC occurred from blue‐PL cI into greenish‐blue‐PL cII. Interestingly, the SCSC phase transition of cI into cII was triggered by thermal stimuli and propagated spontaneously. Thermotriggered domino‐like SCSC phase transition was observed on a fully visible timescale (ca. 125 μm min−1).
Photochemical Hydrogen Evolution at Metal Centers Probed with Hydrated Aluminium Cations, Al+(H2O)n, n=1–10
Authors: Heller Jakob , Pascher Tobias F. , van der Linde Christian , Ončák Milan , Beyer Martin K.
Published: October 2021

Hydrated aluminium cations have been investigated as a photochemical model system with up to ten water molecules by UV action spectroscopy in a Fourier transform ion cyclotron resonance (FT‐ICR) mass spectrometer. Intense photodissociation was observed starting at 4.5 eV for two to eight water molecules with loss of atomic hydrogen, molecular hydrogen and water molecules. Quantum chemical calculations for n=2 reveal that solvation shifts the intense 3s–3p excitations of Al+ into the investigated photon energy range below 5.5 eV. During the photochemical relaxation, internal conversion from S1 to T2 takes place, and photochemical hydrogen formation starts on the T2 surface, which passes through a conical intersection, changing to T1. On this triplet surface, the electron that was excited to the Al 3p orbital is transferred to a coordinated water molecule, which dissociates into a hydroxide ion and a hydrogen atom. If the system remains in the triplet state, this hydrogen radical is lost directly. If the system returns to singlet multiplicity, the reaction may be reversed, with recombination with the hydroxide moiety and electron transfer back to aluminium, resulting in water evaporation. Alternatively, the hydrogen radical can attack the intact water molecule, forming molecular hydrogen and aluminium dihydroxide. Photodissociation is observed for up to n=8. Clusters with n=9 or 10 occur exclusively as HAlOH+(H2O)n‐1 and are transparent in the investigated energy range. For n=4–8, a mixture of Al+(H2O)n and HAlOH+(H2O)n‐1 is present in the experiment.
Development of astrocyte morphology and function in mouse visual thalamus
Authors: Somaiya Rachana D. , Huebschman Natalie A. , Chaunsali Lata , Sabbagh Ubadah , Carrillo Gabriela L. , Tewari Bhanu P. , Fox Michael A.
Published: October 2021

The rodent visual thalamus has served as a powerful model to elucidate the cellular and molecular mechanisms that underlie sensory circuit formation and function. Despite significant advances in our understanding of the role of axon‐target interactions and neural activity in orchestrating circuit formation in visual thalamus, the role of non‐neuronal cells, such as astrocytes, is less clear. In fact, we know little about the transcriptional identity and development of astrocytes in mouse visual thalamus. To address this gap in knowledge, we studied the expression of canonical astrocyte molecules in visual thalamus using immunostaining, in situ hybridization, and reporter lines. While our data suggests some level of heterogeneity of astrocytes in different nuclei of the visual thalamus, the majority of thalamic astrocytes appeared to be labeled in Aldh1l1‐EGFP mice. This led us to use this transgenic line to characterize the neonatal and postnatal development of these cells in visual thalamus. Our data show that not only have the entire cohort of astrocytes migrated into visual thalamus by eye‐opening but they also have acquired their adult‐like morphology, even while retinogeniculate synapses are still maturing. Furthermore, ultrastructural, immunohistochemical, and functional approaches revealed that by eye‐opening, thalamic astrocytes ensheathe retinogeniculate synapses and are capable of efficient uptake of glutamate. Taken together, our results reveal that the morphological, anatomical, and functional development of astrocytes in visual thalamus occurs prior to eye‐opening and the emergence of experience‐dependent visual activity.