bluuebunny/crossref_metadata_2025 huggingface dataset:
Aerobic oxidation-functionalization of the aryl moiety in van Koten's pincer complex (NCN)Ni(ii)Br: relevance to carbon–heteroatom coupling reactions promoted by high-valent nickel species
Authors: Cloutier Jean-Philippe , Zamani Fahimeh , Zargarian Davit
Published: December 2021

Treating the pincer complex (NCN)NiBr with protic substrates HX (X = OH, OR, or NR2) under aerobic conditions leads to C–X functionalization of the pincer ligand. The crucial importance of aerobic conditions for the success of this coupling reaction implies the formation of high-valent intermediates during the course of the reaction.
Tuning the magnetic properties of NiPS3 through organic-ion intercalation
Authors: Tezze Daniel , Pereira José M. , Asensio Yaiza , Ipatov Mihail , Calavalle Francesco , Casanova Felix , Bittner Alexander M. , Ormaza Maider , Martín-García Beatriz , Hueso Luis E. , Gobbi Marco
Published: December 2021

The intercalation of different organic cations in the layered antiferromagnet NiPS3 yields ferrimagnetic ordering with a molecule-dependent transition temperature. A successful intercalation is demonstrated for bulk crystals and exfoliated flakes.
Wafer-scale, highly uniform, and well-arrayed suspended nanostructures for enhancing the performance of electronic devices
Authors: Zhao Zhi-Jun , Ahn Junseong , Lee Dongheon , Jeong Chan Bae , Kang Mingu , Choi Jungrak , Bok Moonjeong , Hwang Soonhyoung , Jeon Sohee , Park Sooyeon , Ko Jiwoo , Chang Ki Soo , Choi Jung-Woo , Park Inkyu , Jeong Jun-Ho
Published: December 2021

Wafer-scale, highly uniform, well-arrayed suspended nanostructures play an important role in enhancing the performance of a diverse group of nanodevices.
Bimetal metal–organic framework domino micro-reactor for synergistic antibacterial starvation/chemodynamic therapy and robust wound healing
Authors: Peng Liming , Yang Xuyang , Wang Song , Chan Yau Kei , Chen Yong , Yang Zhaopu , Mao Yurong , Li Limei , Yang Weizhong , Deng Yi
Published: December 2021

We devised a domino micro-reactor (BMOF-DMR) for long-term anti-infection and robust wound healing, which is achieved through sequences of domino reactions specifically triggered by an infectious microenvironment.
Revisiting the nontemplate approach for the synthesis of highly green emissive hybrid perovskite nanocrystals: platelets or spheres?
Authors: Rosa-Pardo Ignacio , Cevallos-Toledo Rita B. , Polavarapu Lakshminarayana , Arenal Raul , Galian Raquel E. , Pérez-Prieto Julia
Published: December 2021

Hybrid lead halide nanoplatelets of ca. 21 nm lateral size and 4.6 nm thickness were successfully isolated as bright emissive (of up to 93% photoluminescence quantum yield) nanomaterial by using the reverse microemulsion methodology.
Water assisted growth of two-dimensional MoS2/MoSe2 vertical heterostructures on molten glass
Authors: Cai Qian , Ju Qiankun , Hong Wenting , Jian Chuanyong , Wang Taikun , Liu Wei
Published: December 2021

Controlled growth of MoS2/MoSe2 heterostructures on a molten glass substrate was demonstrated with the assistance of water vapor.
Reducing the reprocessing and healing temperature of polyurea with piperazine-based hindered urea bonds
Authors: Wang Fang-Zhou , Wang Hong-Qin , Gao Wen-Tong , Li Cheng-Hui
Published: December 2021

With a novel hindered urea bond, excellent mechanical robustness and recycling ability are well balanced in piperazine-based polyureas.
Visible light promoted polyhalomethylation of alkenes: alkylation and cyclization
Authors: Wang Tong-Lin , Zhang Bo-Sheng , Liu Jing-Jiang , Liu Xiao-Jun , Wang Xi-Cun , Quan Zheng-Jun
Published: December 2021

The report describes a visible light promoted carbochloromethylation of 2-bromomethyl acrylate and N-arylmethacrylamide, and a series of trihalomethyl substituted allylic acid esters and indolone derivatives were synthesized.
Green hydrogen and platform chemicals production from acidogenic conversion of brewery spent grains co-fermented with cheese whey wastewater: adding value to acidogenic CO2
Authors: Sarkar Omprakash , Rova Ulrika , Christakopoulos Paul , Matsakas Leonidas
Published: December 2021

The biotechnological production of fuel and chemicals from renewable, organic carbon-rich substrates offers a sustainable way to meet the increasing demand for energy.
Mn, P co-doped sharp-edged Mo2C nanosheets anchored on porous carbon for efficient electrocatalytic hydrogen evolution
Authors: Mu Zongyun , Guo Ting , Fei Hao , Xu Dingsheng , Mao Yaoqing , Wu Zhuangzhi , Wang Dezhi
Published: December 2021

A Mn, P co-doping strategy is proposed to improve the HER performance of Mo2C for the first time, in which Mn, P co-doping can optimize the electronic configuration of Mo2C.
A 3D hierarchical network derived from 2D Fe-doped NiSe nanosheets/carbon nanotubes with enhanced OER performance for overall water splitting
Authors: Chang Kai , Tran Duy Thanh , Wang Jingqiang , Kim Nam Hoon , Lee Joong Hee
Published: December 2021

A novel electrocatalyst derived from a unique 3D hierarchical network of 2D Fe-doped NiSe nanosheets and CNTs on carbon paper exhibits enhanced OER performance with an overpotential of 282.0 mV to reach 10 mA cm−2 in 1.0 M KOH medium.
Dynamically balancing class losses in imbalanced deep learning
Authors: Zhao Yaochi , Liu Shiguang , Hu Zhuhua
Published: December 2021

Imbalanced datasets commonly exist in real world and greatly challenge the performances of deep neural models. The authors discover that the traditional balance strategies in the existing imbalanced learning methods emphasize/suppress the importance of minority/majority class in a fixed way. Even the minority class is fully represented, the minority/majority class is still emphasized/suppressed, eventually leading to sub‐optimal models. The authors argue that the importance of minority/majority class should be emphasized/suppressed in a dynamic manner. They propose to dynamically balance class losses (DBCL), which first suppresses the importance of majority class, and then gradually restores the importance of majority class. By adding the idea of DBCL into three state‐of‐the‐art cost‐sensitive loss functions, the authors propose three novel loss functions: dynamic constrained‐focal‐loss (DCFL), dynamic balance‐cross‐entropy based on the effective number of samples (DBENS) and dynamic balance‐cross‐entropy based on class frequencies (DBCEF). They apply DCFL, DBENS and DBCEF to the imbalanced learning in salient‐instance segmentation. The results show that their methods significantly improve the classification abilities of models.
Morphology evolution and breakdown mechanism of cross‐linked polyethylene (XLPE)–silicone rubber (SiR) interface induced by silicone grease diffusion
Authors: Li Zerui , Zhou Kai , Meng Pengfei , Yuan Hao , Wang Zikang , Chen Yidong , Li Yuan , Zhu Guangya
Published: December 2021

Silicone grease (SG) is used for lubrication during cable accessory installation and can penetrate into the silicone rubber (SiR), leading to properties deterioration of the SiR. In this study, the effects of SG on the breakdown characteristics of the cross‐linked polyethylene (XLPE)–SiR interface are investigated. First, the variation of the XLPE–SiR interface breakdown voltage with SG coating time is experimentally explored. The interface breakdown voltage significantly increases after SG is applied, remains stable for coating times of up to approximately 144 h and then rapidly decreases; the minimum interface breakdown voltage is lower than that without the SG coating. Next, the effects of SG on the chemical composition and surface topography of the SiR are examined by infrared spectroscopy and optical profilometry, respectively. The SG penetration does not change the functional groups of the SiR but significantly increases its surface roughness. Finally, the interface electric‐field distribution after coating with SG is analysed by finite‐element simulation, revealing that the residual SG at the interface distorts the interface electric field after a long coating time. The increase in the SiR surface roughness caused by SG diffusion and the interface electric‐field distortion caused by the residual SG together lead to the decrease of the interface breakdown voltage.
A social relationship preference aware peer‐to‐peer energy market for urban energy prosumers and consumers
Authors: Zhao Zehua , Luo Fengji , Zhang Chunming , Ranzi Gianluca
Published: December 2021

Increasingly prevalence of distributed energy resources (such as solar panels and wind turbines) has been transforming traditional energy consumers to become energy prosumers (producers‐and‐consumers). This in turn drives the development of peer‐to‐peer energy trading, which refers to trading energy generated by distributed energy resources directly among energy prosumers and consumers. This paper proposes a new peer‐to‐peer electricity market prototype that facilitates energy trading among energy prosumers and consumers with consideration of their preferences in terms of social relationships with each other. A data‐driven social network model is established to represent the bilateral social relationships of the market participants. Based on that, an auction‐based electricity trading mechanism is proposed to facilitate the participants to make end‐to‐end energy trading decisions by simultaneously considering energy trading prices and social relationship preferences. Numerical simulations based on real‐world datasets are conducted to validate the proposed system.
A new analytical scattering phase function for interstellar dust
Authors: Baes Maarten , Camps Peter , Kapoor Anand Utsav
Published: December 2021

Context.Properly modelling scattering by interstellar dust grains requires a good characterisation of the scattering phase function. The Henyey-Greenstein phase function has become the standard for describing anisotropic scattering by dust grains, but it is a poor representation of the real scattering phase function outside the optical range.

Aims.We investigate alternatives for the Henyey-Greenstein phase function that would allow the scattering properties of dust grains to be described. Our goal is to find a balance between realism and complexity: the scattering phase function should be flexible enough to provide an accurate fit to the scattering properties of dust grains over a wide wavelength range, and it should be simple enough to be easy to handle, especially in the context of radiative transfer calculations.

Methods.We fit various analytical phase functions to the scattering phase function corresponding to the BARE-GR-S model, one of the most popular and commonly adopted models for interstellar dust. We weigh the accuracy of the fit against the number of free parameters in the analytical phase functions.

Results.We confirm that the Henyey-Greenstein phase functions poorly describe scattering by dust grains, particularly at ultraviolet (UV) wavelengths, with relative differences of up to 50%. The Draine phase function alleviates this problem at near-infrared (NIR) wavelengths, but not in the UV. The two-term Reynolds-McCormick phase function, recently advocated in the context of light scattering in nanoscale materials and aquatic media, describes the BARE-GR-S data very well, but its five free parameters are degenerate. We propose a simpler phase function, the two-term ultraspherical-2 (TTU2) phase function, that also provides an excellent fit to the BARE-GR-S phase function over the entire UV-NIR wavelength range. This new phase function is characterised by three free parameters with a simple physical interpretation. We demonstrate that the TTU2 phase function is easily integrated in both the spherical harmonics and the Monte Carlo radiative transfer approaches, without a significant overhead or increased complexity.

Conclusions.The new TTU2 phase function provides an ideal balance between being simple enough to be easily adopted and realistic enough to accurately describe scattering by dust grains. We advocate its application in astrophysical applications, in particular in dust radiative transfer calculations.
On the impact of corruption on managers’ and controllers’ behavior
Authors: Belhaiza Slim , Charrad Salwa , M’Hallah Rym
Published: December 2021

In this paper, we study the impact of corruption in the context of a game involving a manager and a controller. We propose a model where the controller initiates the bribe demand from the manager. We identify the structure of three potential subgame perfect Nash equilibria, and show their uniqueness. Next, we analyze the influence of the corruption parameters (bribery amount, reciprocity bonus and reputation gain) and the manager’s and the controller’s bonuses/penalties on the equilibria. Finally, we explain how the manager and the controller may increase, decrease or maintain their performance, when the bribery amount, the reciprocity bonus or the reputation gain index increase.
Hairy Cell Leukemia: Morphological and Immunophenotypic Characteristics of Seven Cases and Cyclin D1 Expression
Authors: Ramesh Shruti Neelamegam , Padhi Somanath , Adhya Amit K. , Panigrahi Ashutosh , Das Prabodha K. , Patra Susama
Published: December 2021

Aberrant immunophenotypic expression in hairy cell leukemia (HCL), both at medullary and extramedullary sites, is not uncommonly reported in literature. Cyclin D1 positivity in HCL may mimic mantle cell lymphoma (MCL) morphologically, especially in the presence of aberrant CD5 immunopositivity, requiring BRAFV600E mutation and/or CCND1 gene testing for confirmation. Here, we describe seven cases of HCL with clinicomorphological and immunophenotypic characteristics with an emphasis on cyclin D1 expression using immunohistochemistry (IHC) with a brief comprehensive literature review. We suggest that cyclin D1 positive HCL may be a distinct subtype which requires further immunophenotypic and molecular characterization for accurate diagnosis and planning of definitive therapy.
A Retrospective Observational Study of Problems Faced by Children and Adolescents with Cancer: A 5-year Experience from a Pediatric Psycho-Oncology Service in India
Authors: Deodhar Jayita , Goswami Savita S. , Sonkusare Lekhika N.
Published: December 2021

Introduction Psychological concerns are common in children and adolescents with cancer, for which they require referral to specialist services. There is a dearth of pediatric psycho-oncology services in India. There are limited studies on emotional and related distress in children.

Objectives To evaluate the types of problems and associated factors in children and adolescents with cancer referred to the pediatric psycho-oncology service in a tertiary care oncology center in India.

Materials and Methods A retrospective analysis of all referrals to the institution's pediatric psycho-oncology service over 5 years was performed. Patients newly referred to the service, up to 18 years of age, with a cancer diagnosis, on active disease-modifying treatment or supportive care or following up within 2 years of completion of treatment were included. Patients not on any disease-modifying treatment and receiving the best supportive care only were excluded as needs and problems would differ in this group. Patients whose medical records were incomplete were excluded too. Descriptive measures and tests of association were performed for analysis.

Results Of the 278 children referred to the service in 5 years, 66.5% were males. The average age was 11 years (standard deviation [SD]: 4.5). Most children had hematolymphoid cancers (58.2%). All reported problems were mainly emotional/behavioral (59%), physical health-related (21%), and academic (14%). Male children, referred from outpatient clinics and undergoing treatment with palliative intent, had more emotional problems, but these factors were not statistically significant.

Conclusion Children and adolescents with cancer had different problems, most commonly emotional/behavioral and physical health-related. Age, gender, and treatment intent were factors associated with emotional problems. Psychosocial care services for children and adolescents with cancer are necessary for low-resource settings.
Enantioselective aza-Michael Cyclization Reaction Catalyzed by Quinine-Derived Monoquaternary Ammonium Salts: an Effective Route to Synthesize Letermovir
Authors: Chen Liang , Liu Wei-Yuan , Bi Si-Ju , Zhou Ting , Pan Jing , Lv Xun-Lei , Lin Kuai-Le , Zhou Wei-Cheng
Published: December 2021

A series of mono- or bis-quaternary ammonium salts derived from cinchonidine or quinine was synthesized and screened as potent phase-transfer catalysts for the reaction of aza-Michael cyclization, the key step in the synthesis of letermovir. During the reaction of aza-Michael cyclization, the screened monoquaternary ammonium salt quinine derivative Q1 transferred 7 to 8 with 91.9% yield and 58% ee. The application of Q1 was preferred, due to its enantioselectivity, the possibility of reuse, and the lower cost in large-scale preparation. Furthermore, the racemization condition of letermovir enantiomer was also explored for the possibility to develop the resolution/racemization process. With the optimal catalyst Q1 in hand, the synthesis of letermovir may be more convenient and economical in the future.
Improvement of Sleep Quality after Surgical Decompression in Carpal Tunnel Syndrome
Authors: Hieu Nguyen Le Trung , Sang Nguyen Anh , Vuong Nguyen Lam
Published: December 2021

Background Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy which can cause severe sleep disturbance. Carpal tunnel release (CTR) is a choice for severe cases, which has shown to improve sleep quality, but the available evidence is limited. This study aimed to investigate the impact of CTR on sleep quality and hand symptoms and functions in patients with CTS.

Methods This was a prospective study in 2019–2020 on patients with CTS and poor sleep quality undergoing CTR. Patients were evaluated before and at 1, 3, and 12 months after CTR by the Pittsburgh sleep quality index (PSQI) and Boston carpal tunnel syndrome questionnaires.

Results There were 33 patients with 27 females (82%) and a median age of 51 years. The median time of CTS diagnosis and having sleep disorder before CTR were 12 and 6 months, respectively. The outcomes significantly improved after CTR, with the median PSQI and Boston symptom and function scores reduced from 12, 33, and 23 before CTR to 9, 14, and 11 at 1 month; 7, 13, and 9 at 3 months; and 1, 11, and 8 at 12 months postoperatively, respectively. The correlations between the PSQI and Boston symptom and function scores were > 0.6 at all time-points.

Conclusions Surgical decompression significantly improves sleep quality and the hand symptoms and functions in patients with CTS. Long-term evaluations are lacking and thus are required in future studies.
A framework for causal discovery in non-intervenable systems
Authors: van Leeuwen Peter Jan , DeCaria Michael , Chakraborty Nachiketa , Pulido Manuel
Published: December 2021

Many frameworks exist to infer cause and effect relations in complex nonlinear systems, but a complete theory is lacking. A new framework is presented that is fully nonlinear, provides a complete information theoretic disentanglement of causal processes, allows for nonlinear interactions between causes, identifies the causal strength of missing or unknown processes, and can analyze systems that cannot be represented on directed acyclic graphs. The basic building blocks are information theoretic measures such as (conditional) mutual information and a new concept called certainty that monotonically increases with the information available about the target process. The framework is presented in detail and compared with other existing frameworks, and the treatment of confounders is discussed. While there are systems with structures that the framework cannot disentangle, it is argued that any causal framework that is based on integrated quantities will miss out potentially important information of the underlying probability density functions. The framework is tested on several highly simplified stochastic processes to demonstrate how blocking and gateways are handled and on the chaotic Lorentz 1963 system. We show that the framework provides information on the local dynamics but also reveals information on the larger scale structure of the underlying attractor. Furthermore, by applying it to real observations related to the El-Nino–Southern-Oscillation system, we demonstrate its power and advantage over other methodologies.
Formation of inverted pyramid-like structures on surfaces of single crystalline silicon solar cells by chemical wet etching
Authors: Wang Hua-Wei , Yen Henry , Liu Pang-Kai , Wang Likarn
Published: December 2021

We present a new, simple, and cost-effective etching method for forming inverted pyramid-like structures on the surfaces of single-crystalline diamond-wire sawn silicon wafers. The method follows a three-step process for etching silicon wafers without metal-assisted chemical etching involved. We used acidic etching to produce nano-to-micro-structured caves in the first two steps followed by anisotropic etching with an alkaline solution. This paper shows that the size of the opening of the inverted pyramid could vary from several hundred nanometers to about 4 μm, depending on the etch time periods in the second and the third steps. The cell performance was, however, only evaluated here for cases of smaller sizes of inverted pyramids. That is, solar cells were manufactured following an almost commercially standard procedure by using wafers with inverted pyramids of ∼900 nm in size. The best cell with this type of structure has a conversion efficiency of 19.22%, which is higher relative to the cells with smaller inward recessed caves or upright pyramids on the surfaces.
Complex network analysis of spatiotemporal dynamics of premixed flame in a Hele–Shaw cell: A transition from chaos to stochastic state
Authors: Nomi Yuji , Gotoda Hiroshi , Fukuda Shingo , Almarcha Christophe
Published: December 2021

We study the dynamical state of a noisy nonlinear evolution equation describing flame front dynamics in a Hele–Shaw cell from the viewpoint of complex networks. The high-dimensional chaos of flame front fluctuations at a negative Rayleigh number retains the deterministic nature for sufficiently small additive noise levels. As the strength of the additive noise increases, the flame front fluctuations begin to coexist with stochastic effects, leading to a fully stochastic state. The additive noise significantly promotes the irregular appearance of the merge and divide of small-scale wrinkles of the flame front at a negative Rayleigh number, resulting in the transition of high-dimensional chaos to a fully stochastic state.
Recent advances of luminogens with aggregation-induced emission in multi-photon theranostics
Authors: Fan Miaozhuang , Xu Zhourui , Liu Maixian , Jiang Yihang , Zheng Xiaomin , Yang Chengbin , Law Wing-Cheung , Ying Ming , Wang Xiaomei , Shao Yonghong , Swihart Mark T. , Xu Gaixia , Yong Ken-Tye , Tang Ben Zhong
Published: December 2021

Multi-photon theranostics, involving the absorption of two or three photons by luminogens, has come to occupy an important place in biomedical research, with its ability to allow real-time observation/treatment of dynamic structures in living cells and organisms. Luminogens with aggregation-induced emission characteristics are recognized as perfect candidates for multi-photon agents, owing to their flexibility of design, resistance to photobleaching, robust stability, and reduced cytotoxicity. Hence, in recent years, significant breakthroughs in design and application of such luminogens have been reported. In this review, we summarize the latest advances in molecular guidelines and photophysical process control for developing luminogens with large multi-photon action cross section. Special attention is paid to how the molecular structure and intermolecular interactions influence the intramolecular charge transfer, and how new strategies have been developed to advance the multi-photon imaging and therapeutic performance. With this review, we hope to encourage further exploitation of luminogens with aggregation-induced emission characteristics to advance multi-photon theranostics.
Shortcomings of the Derjaguin–Muller–Toporov model in dynamic atomic force microscopy
Authors: Theiler Pius M. , Ritz Christian , Stemmer Andreas
Published: December 2021

Force–distance curves recorded by frequency modulated atomic force microscopy (FM AFM) provide insight into the tip–sample mechanics. For quantitative analysis, FM AFM is able to separate conservative from dissipative forces by simultaneously measuring amplitude–distance and frequency–distance curves. Here, we report on the conservative forces in the gentle tip–sample contact of mesoscopic tips at low Tabor parameters. We introduce an analytical expression for the frequency shift based on the Derjaguin–Muller–Toporov (DMT) contact model to simplify the comparison between the experiment and theory. From the analytical formulas, a scaling law between the tip radius and minimal frequency shift is found, which is supported by experimental data. Although excellent fits for full frequency–distance curves are possible, the resulting material properties do not match the accepted literature values. We suspect that these flaws are a consequence of the incomplete treatment of attractive forces and DMT’s strain-stiffness approximation, rendering DMT-based models inappropriate to measure material properties by dynamic AFM in gentle contact.
Shock compression response of additively manufactured AlSi10Mg
Authors: Specht Paul E. , Brown Nathan P.
Published: December 2021

We measured the Hugoniot, Hugoniot elastic limit (HEL), and spallation strength of laser powder bed fusion (LPBF) AlSi10Mg via uniaxial plate-impact experiments to stresses greater than 13 GPa. Despite its complex anisotropic microstructure, the LPBF AlSi10Mg did not exhibit significant orientation dependence or sample-to-sample variability in these measured quantities. We found that the Hugoniot response of the LPBF AlSi10Mg is similar to that of other Al-based alloys and is well approximated by a linear relationship: us=5.49+1.39up. Additionally, the measured HELs ranged from 0.25 to 0.30 GPa and spallation strengths ranged from 1.16 to 1.45 GPa, consistent with values reported in other studies of LPBF AlSi10Mg and Al-based alloys. Strain-rate and stress dependence of the spallation strength were also observed.
Phospholipase A2 inhibitor and LY6/PLAUR domain-containing protein PINLYP regulates type I interferon innate immunity
Authors: Liu Zhongshun , Jiang Congwei , Lei Zhangmengxue , Dong Sihan , Kuang Linlin , Huang Chenxu , Gao Ying , Liu Mu , Xiao Hui , Legembre Patrick , Jung Jae U. , Liang Huaping , Liang Xiaozhen
Published: December 2021

Significance

Interferon (IFN)-mediated antiviral responses serve as the first line of the host innate immune defense against viral infection. Here we identify a previously uncharacterized protein designated phospholipase A2 inhibitor and LY6/PLAUR domain-containing protein (PINLYP), which is essential for embryonic development and plays an important role in type I IFN against pathogen infection. PINLYP deficiency impairs type I IFN production and dampens in vivo host defense against DNA and RNA virus infection. We unravel a unique actor in the type I IFN innate immunity and a potential target for the antiviral therapies.
Microstratigraphic preservation of ancient faunal and hominin DNA in Pleistocene cave sediments
Authors: Massilani Diyendo , Morley Mike W. , Mentzer Susan M. , Aldeias Vera , Vernot Benjamin , Miller Christopher , Stahlschmidt Mareike , Kozlikin Maxim B. , Shunkov Michael V. , Derevianko Anatoly P. , Conard Nicholas J. , Wurz Sarah , Henshilwood Christopher S. , Vasquez Javi , Essel Elena , Nagel Sarah , Richter Julia , Nickel Birgit , Roberts Richard G. , Pääbo Svante , Slon Viviane , Goldberg Paul , Meyer Matthias
Published: December 2021

Significance

DNA preserved in sediments has emerged as an important source of information about past ecosystems, independent of the discovery of skeletal remains. However, little is known about the sources of sediment DNA, the factors affecting its long-term preservation, and the extent to which it may be translocated after deposition. Here, we show that impregnated blocks of intact sediment are excellent archives of DNA. DNA distribution is highly heterogeneous at the microscale in the cave sediment we studied, suggesting that postdepositional movement of DNA is unlikely to be a common phenomenon in cases where the stratigraphy is undisturbed. Combining micromorphological analysis with microstratigraphic retrieval of ancient DNA therefore allows genetic information to be associated with the detailed archaeological and ecological record preserved in sediments.
Menstrual irregularity as a biological limit to early pregnancy awareness
Authors: Nobles Jenna , Cannon Lindsay , Wilcox Allen J.
Published: December 2021

US state legislatures have proposed laws to prohibit abortion once the earliest embryonic electrical activity is detectable (fetal “heartbeat”). On average, this occurs roughly 6 wk after the last menstrual period. To be eligible for abortion, people must recognize pregnancy very early in gestation. The earliest symptom of pregnancy is a missed period, and irregular menstrual cycles—which occur frequently—can delay pregnancy detection past the point of fetal cardiac activity. In our analysis of 1.6 million prospectively recorded menstrual cycles, cycle irregularity was more common among young women, Hispanic women, and women with common health conditions, such as diabetes and polycystic ovary syndrome. These groups face physiological limitations in detecting pregnancy before fetal cardiac activity. Restriction of abortion this early in gestation differentially affects specific population subgroups, for reasons outside of individual control.
Post-arc current measurement and interruption performance of vacuum interrupter in DC interruption
Authors: Tang Qiang , Jia Shenli , Shi Zongqian , Mo Yongpeng
Published: December 2021

In the DC grid, fault current rises very fast due to low impedance. Fast DC circuit breakers are needed to isolate faults and avoid a collapse of the common DC grid voltage. Based on the forced current zero (CZ) technology, the vacuum interrupter (VI) equipped with fast electromagnetic repulsion mechanism is a very promising solution of fast DC interruption. The experimental research on the DC interruption characteristics of a VI, namely by examining the post-arc current (PAC) is presented in this paper. The dependence of the interruption capability on the PAC is analysed. What’s more, the failure modes of the VI under various experiment conditions are summarized. A former finding was that not all the arcing history which starts from the electrodes separating to the CZ has influence on the PAC but only a very short duration of several microseconds right before the CZ takes effects. New experiment results are added in this paper to support the former finding. Another former finding was that a longer electrode separation will bring about higher PAC. In this paper, both the influence of the arcing memory time and the electrodes separation are owed to a higher residual plasma density, which is verified by a model for calculating the residual plasma density and the continuous transient model (CTM) for calculating PAC.
Development of non-invasive blood glucose regression based on near-infrared spectroscopy combined with a deep-learning method
Authors: Wang Zhuyu , Zhou Linhua , Liu Tianqing , Huan Kewei , Jia Xiaoning
Published: December 2021

Extracting micro-scale spectral features from dynamic blood glucose concentrations is extremely difficult when using non-invasive measurement methods. This work proposes a new machine-learning method based on near-infrared spectroscopy, a deep belief network (DBN), and a support vector machine to improve prediction accuracy. First, the standard oral glucose tolerance test was used to collect near-infrared spectroscopy and actual blood glucose concentration values for specific wavelengths (1200, 1300, 1350, 1450, 1600, 1610, and 1650 nm); the blood glucose concentrations were within a clinical range of 70 ∼ 220 mg dl−1. Second, based on the DBN model, high-dimensional deep features of the non-invasive blood glucose spectrum were extracted. These were used to establish a support vector regression (SVR) model and to quantitatively analyze the influence of the spectral sample size and corresponding feature dimensions (i.e. DBN structure) on prediction accuracy. Finally, based on data from six volunteers, a comparative analysis of the SVR model’s prediction accuracy was performed both before and after using high-dimensional deep features. For volunteer 1, when the DBN-based high-dimensional deep features were used, the root mean square error of the SVR model was reduced by 71.67%, and the correlation coefficient (R
2) and the P value of the Clark grid analysis (P) were increased by 13.99% and 6.28%, respectively. Moreover, we had similar results when the proposed method was carried out on the data of other volunteers. The results show that the presented algorithm can play an important role in dynamic non-invasive blood glucose concentration prediction and can effectively improve the accuracy of the SVR model. Further, by applying the algorithm to six independent sets of data, this research also illustrates the high-precision regression and generalization capabilities of the DBN-SVR algorithm.
Layer-dependent fracture strength of few-layer WS2 induced by interlayer sliding: a molecular dynamics study
Authors: Zhan Hao , Tan Xinfeng , Zhang Xin , Xie Guoxin , Guo Dan
Published: December 2021

Understanding the relationship between interlayer interactions and the mechanical properties and behaviors of two-dimensional layered materials is critical in the development of related nanodevices. Nevertheless, it is still challenging due to difficulties in experiments. In this work, nanoindentation simulations on few-layer WS2 were conducted by varying the tip radius, suspended membrane radius, and membrane size using a molecular dynamics simulation. Consistent with our previous experimental results, few-layer WS2 exhibited a layer-dependent reduction in fracture strength owing to the uneven stress distribution among individual layers induced by interlayer sliding under out-of-plane deformation. Furthermore, apparent curve hysteresis was observed due to interlayer sliding in the supported region when a large tip radius and membrane radius were employed. However, instead of the supported part, the interlayer sliding within the suspended part resulted in reduced fracture strength with the increase of layer number. These findings not only provide an in-depth comprehension of the influence of interlayer sliding on fracture strength of few-layer WS2, but also suggest that the role of interlayer interactions should be seriously considered during nanodevice design.
Refractive index and temperature dual parameter sensor based on a twin-core photonic crystal fiber
Authors: Yin Zhiyong , Jing Xili , Feng Yuhui , Gao Zhigang , Wu Biao , Wang Chengjun
Published: December 2021

A twin-core photonic crystal fiber sensor is proposed for measuring liquid refractive index (RI) and temperature simultaneously. The air holes of the sensor are arranged in a hexagonal pattern, and two planes are introduced by polishing in the cladding. On one side of the plane, the gold film is deposited for RI measurement, and on the other side, the gold film and polydimethylsiloxane are deposited for temperature measurement. We analyzed its sensing characteristics by using the finite element method. The numerical results show that the two channels for measuring RI and temperature have no mutual interference and the arrangement reduces the complexity of the sensing measurement. The maximum spectral sensitivity of the sensor is 20 000 nm/RIU and 9.2 nm °C−1, respectively, when the liquid RI is in the range of 1.36–1.42 and the temperature is in the range of 0 °C–50 °C. The results also show the sensing accuracy was not very sensitive to the change of structural parameters, which makes the sensor very easy to fabricate. Our work is very helpful for implementation of a high sensitivity, easy fabrication and real-time multi-parameter surface plasmon resonance sensor.
Fault diagnosis of a planetary gearbox based on a local bi-spectrum and a convolutional neural network
Authors: Lingli Jiang , Shuhui Li , Xuejun Li , Jiale Lei , Dalian Yang
Published: December 2021

The transmission paths of vibration signals in the planetary gearboxes are complex. The signals have the characteristics of strong background noise, instability and non-Gaussian. Bi-spectrums can suppress Gaussian colored noise and are suitable for vibration signal processing of planetary gearboxes. In the traditional fault diagnosis methods based on bi-spectrums, the amplitudes of fault characteristic frequency, or the other further quantitative calculations values, are generally used as the basis of fault diagnosis processes. It has been found that bi-spectrum images can directly characterize the faults of the planetary gearboxes. Convolutional neural networks (CNNs) have been used in mechanical fault diagnoses in recent years. One-dimensional original signals are converted into two-dimensional images as CNN input, which is an effective method for mechanical fault diagnoses. At the present time, there has not been any relevant research conducted using bi-spectral images as CNN input. In this study, a fault diagnosis method based on local bi-spectrum and CNN was proposed. A bi-spectral analysis of the vibration signals of the planetary gearbox was first carried out in order to reveal the fault information while retaining the non-Gaussian information. Then, according to the bi-spectrum symmetry, local images containing the main information were taken as the input of the CNN, which reduced the redundancy of the fault information. Then, in order to improve the diagnostic accuracy of the CNN, the key parameters of CNN architecture were optimized. Finally, a CNN diagnosis model was built to realize the classification diagnoses of different fault positions and different fault degrees of planetary gearboxes. This study’s comparison of the diagnosis results of the full bi-spectrum + CNN, original vibration signal + CNN, local bi-spectrum + (support vector machines), and local bi-spectrum + (stacked auto-encoder) showed that the proposed method in this study had achieved both accuracy and rapidity in the fault diagnoses of planetary gearboxes.
A single foot-mounted pedestrian navigation algorithm based on the maximum gait displacement constraint in three-dimensional space
Authors: Wang Jianyu , Liu Jinhao , Xu Xiangbo , Yu Zhibin , Li Zhe
Published: December 2021

Inertial navigation technology composed of inertial sensors is widely used in foot-mounted pedestrian positioning. However, inertial sensors are susceptible to noise, which affects the performance of the system. Zero-velocity update (ZUPT) is a traditional method utilized to suppress the cumulative error. Unfortunately, the walking distance calculated by a Kalman filter still has positional error. To improve the positional accuracy, in this work we propose a nonlinear Kalman filter with a spatial distance inequality constraint for a single foot. Since the stride distance between adjacent stance phases has an upper bound in plane and height, an inertial navigation system established by one inertial measurement unit is adopted to constrain the stride process. Eventually, the performance of the proposed method is verified by experiments. Compared with the single foot-mounted ZUPT method, the proposed method suppresses the plane error and the height error by 46.04% and 65.48%, respectively. For the dual-foot constraint method, the proposed constraint method can reduce the number of sensors while ensuring positioning accuracy. Moreover, the height error is reduced by 59.98% on average by optimizing the constraint algorithm. The experimental results show that the trajectory estimated by the proposed method is closer to the actual path.
ZnO nanoparticles and β-cyclodextrin containing molecularly imprinted polymers for gravimetric sensing of very-low-density lipoprotein
Authors: Nasrullah Amara , Roshan Sumaira , Latif Usman , Mujahid Adnan , Mustafa Ghulam , Bajwa Sadia Z , Afzal Adeel
Published: December 2021

The elevated level of very-low-density lipoprotein (VLDL) in the blood is associated with coronary heart disease; therefore, its detection is of significant clinical importance. In this work, molecularly imprinted polymer (MIP) layers fabricated with ZnO nanoparticles are developed for gravimetric sensing of VLDL. The use of methacrylic acid and β-cyclodextrin as functional co-monomers in an optimized ratio of 1:1 for MIP synthesis controls the hydrophilicity/hydrophobicity; thus, yielding highly tailored recognition sites having adequate stability. The as-prepared ZnO nanoparticles are characterized by scanning electron microscopy, Fourier transformation infrared, and x-ray diffraction before incorporating into the MIP matrix. The template concentration in MIP is also varied to select its optimal amount, i.e. 50 µl of 50 µg ml−1 VLDL solution for enhanced sensor performance. Sensor measurements reveal that the ZnO-MIP has a sensitivity of 19.285 Hz ng−1 ml−1 for VLDL, which is about 16-fold higher than the reference ZnO-non-imprinted polymer channel. Furthermore, the ZnO-MIP sensor exhibits high selectivity for VLDL as the sensor response is 6 and 3 times higher compared to α1-acid glycoprotein and human serum albumin, respectively. Finally, the performance of the developed sensor setup is evaluated for the detection of VLDL in human serum samples indicating its potential for reliable analysis of VLDL in complex biofluids.
Scanning probe analysis of twisted graphene grown on a graphene/silicon carbide template
Authors: Yao Yao , Negishi Ryota , Takajo Daisuke , Takamura Makoto , Taniyasu Yoshitaka , Kobayashi Yoshihiro
Published: December 2021

Overlayer growth of graphene on an epitaxial graphene/silicon carbide (SiC) as a solid template by ethanol chemical vapor deposition is performed over a wide growth temperature range from 900 °C to 1450 °C. Structural analysis using atomic force and scanning tunneling microscopies reveal that graphene islands grown at 1300 °C form hexagonal twisted bilayer graphene as a single crystal. When the growth temperature exceeds 1400 °C, the grown graphene islands show a circular shape. Moreover, moiré patterns with different periods are observed in a single graphene island. This means that the graphene islands grown at high temperature are composed of several graphene domains with different twist angles. From these results, we conclude that graphene overlayer growth on the epitaxial graphene/SiC solid at 1300 °C effectively synthesizes the twisted few-layer graphene with a high crystallinity.
A low-cost spectrometer to analyse the purity of honey
Authors: Bestari L F , Sarwanto  , Pujayanto  , Syam W P , Harjunowibowo D
Published: December 2021

Light spectrum dispersion is an exciting subjectin science because of its beautiful atmospheric colour phenomenon which attracts students. However, to see the phenomenon is not easy since it needs a spectrometer, which is commonly expensive. Therefore, the present study aims to describe a low-cost spectrometer for investigating lighting spectrum and analysing the purity of honey as a pedagogical students’ project. The spectrometer was constructed from a webcam connected to a laptop, a free spectrometer software, DVD disk, and black cardboard. The calibration of the developed spectrometer used an Argon (Ar) lamp. Afterwards, measurement tests were carried out by using Neon (Ne) and Xenon (Xe) lamps. A white light-emitting diode was used as a light source to measure several types of honey wavelengths. The results from the experiment show that the wavelength of Ar, Ne, and Xe are (503 ± 4) nm, (463 ± 3) nm, and (451 ± 3) nm respectively. The measurement accuracy of the spectrometer is 99.5%. In addition, the commercial honey characterisations show that pure honey tends to have an excellent and smooth spectrum with one peak. On the contrary, the adulteries honeys show a rough wave with many peaks representing the inhomogeneous ingredients. It is found that the average accuracy for honey spectrum is 99.8%. Moreover, the low-cost spectrometer can be built and used easily by students for educational purposes.
Energy transport in

Z3

chiral clock model
Authors: Nishad Naveen , Sreejith G J
Published: December 2021

We characterize the energy transport in a one dimensional

Z

3

chiral clock model. The model generalizes the

Z

2

symmetric Transverse Field Ising Model (TFIM). The model is parametrized by a chirality parameter θ, in addition to f and J which are analogous to the transverse field and the nearest neighbor spin coupling in the TFIM. Unlike the well-studied TFIM and XYZ models, this model does not transform to a fermionic system. We use a matrix product states implementation of the Lindblad master equation to obtain the Non-Equilibrium Steady State (NESS) in systems of sizes up to 48. We present the estimated NESS current and its scaling exponent γ as a function of θ at different f/J. The estimated γ(f/J, θ) points to ballistic energy transport along a line of integrable points f = J cos 3θ in the parameter space; all other points deviate from ballistic transport. Analysis of finite size effects within the available system sizes suggest diffusive behavior away from the integrable points.
Structural, optical, and potential broad-spectrum antibacterial properties of CuO-Ag nanoparticles biosynthesized using the extract of Diospyros discolor Willd
Authors: Handayani Windri , Imawan Cuk , Umar Aminah , Yasman  , Yunilawati Retno , Djuhana Dede
Published: December 2021

The development of new material properties for antimicrobial agents to address the problem of antibiotic resistance is currently being explored. Silver and copper exhibit oligodynamic properties, which inhibit the growth of microorganisms. These properties are stronger at the nanoscale than the macroscale, especially for bimetallic nanoparticles (NPs). In this study, we synthesized bimetallic CuO and Ag NPs using Diospyros discolor Willd. (Velvet apple) leaf extract with three different ratios of Cu and Ag precursors: 1:0.01, 1:0.1, and 1:1 (v/v). In addition, the optical properties of these NPs were characterised using UV-Vis spectrophotometer, which showed the typical absorbance peak in the range of 300–400 nm. The size and shape of the CuO and Ag nanoparticles were analysed using a scanning electron microscope (SEM) and transmission electron microscope (TEM) images. The SEM and TEM images showed leaf-shaped CuO nanoplates and spherical AgNPs. Furthermore, the crystalline properties were analysed using x-ray diffraction (XRD). This study produced CuO-Ag nanoclusters with a particular morphology, size, and composition. The antibacterial assay showed potential broad-spectrum activity for Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis) as well as Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa).
Super-resolution imaging of negative-refractive graded-index photonic crystal flat lens
Authors: Liang Binming , Huang Xiao , Zheng Jihong
Published: December 2021

Photonic crystal (PC) not only breaks through the diffraction limit of traditional lenses but also can realize super-resolution imaging. Improving the resolution is the key task of PC imaging. The main work of this paper is to use a graded-index Photonic crystal (GPC) flat lens to improve the image resolution. An air-hole type two-dimensional (2D) GPC structure based on silicon medium is proposed in this paper. Numerical simulations through RSoft reveal that when the medium in the imaging area is air, the full width at half maximum (FWHM) value of a single image reaches

0.362
λ
.

According to the Rayleigh criterion, the images of two point sources

0.57
λ

apart can also be distinguished. In the imaging system composed of cedar oil and GPC flat lens, the FWHM value of a single image reaches

0.34
λ
.

In addition, the images of multiple point sources

0.49
λ

apart can still be distinguished.