bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of superstrong magnetic field on neutrino energy loss of the nuclide 56Fe, 56Co, 56Ni, 56Mn and 56Cr by electron capture in the crust of neutron stars
Authors: Liu Jing-Jing  ,   College of Science and Technology, Qiongzhou University, Sanya 572022, China
Published: December 2020

We investigated the neutrino energy loss by electron capture of the nuclide 56Fe, 56Co, 56Ni, 56Mn and 56Cr in superstrong magnetic field at the crusts of neutron stars. The results showed that the superstrong magnetic field has only a slight effect on the neutrino energy loss rates when B13 G on surfaces of most neutron stars. Whereas for some magnetars, the range of the magnetic field is 1013—1015 G, the neutrino energy loss rates would be lowered greatly and may be even decreased more than five orders of magnitude by superstrong magnetic field.
Dynamical properties of quantum ring under the stepped pulse bias
Authors: Guo Yan-Jiang  , Xiong Yong-Jian  ,   宁波重点纳米实验室，宁波大学物理系，宁波  315211
Published: December 2020

The dynamical properties of a one-dimensional quantum ring with a constant magnetic flux are studied using the non-equilibrium Green’s function method. The ring is coupled through a single lead to an electron reservoir, which is driven by a stepped pulse bias. We provide a numerical method to calculate current in the presence of stepped bias. Our results reveal the relation between the evolution of tunneling current and electron energy levels of the ring.
Grainboundary electronic structure of ZnO-Bi2O3 based varistor ceramics
Authors: Cheng Peng-Fei  , Li Sheng-Tao  , Li Jian-Ying  ,   (1)西安工程大学理学院，西安  710048; (2)西安交通大学电力设备电气绝缘国家重点实验室，西安  710049
Published: December 2020

Dielectric frequency spectra of ZnO-Bi2O3 based varistor ceramics were measured in the frequency range of 10-2Hz—106Hz from -100℃ to 20℃ by Novocontrol broadband dielectric spectrometer. The intrinsic defect structure of ZnO was calculated according to the theory which assumes that characteristics dielectric loss peaks of ZnO varistor ceramics origin from electronic relaxation process of intrinsic defects in depletion layer. At the same time the micro-electric parameters of grainboundary and the single grainboundary breakdown voltage Vb were obtained. The accordance of theory with experiment in Vb value indicates that the method to calculate grainboundary electronic structure by dielectric spectroscopy proposed in this paper is resonable.
Development of the transient spin grating system and its application in the study of spin transport
Authors: Hu Chang-Cheng  , Wang Gang  , Ye Hui-Qi  , Liu Bao-Li  ,   (1)北京凝聚态物理国家实验室，中国科学院物理研究所固态量子信息与计算实验室,北京  100190; (2)北京凝聚态物理国家实验室，中国科学院物理研究所固态量子信息与计算实验室,北京  100190；吉林大学物理学院,长春  130021
Published: December 2020

Transient spin grating, as a novel technique in ultrafast magneto-optical laser spectroscopy, is widely used to study the properties of spin transport in semiconductor low-dimensional structures. The principle of transient spin grating and the optical arrangement are described briefly in this paper, which includes the generation and detection of transient spin grating. The signal to noise ratio was significantly enhanced by using heterodyne detection. The spin diffusion coefficient Ds was determined by this technique to be about 551cm/s in (110) GaAs/AlGaAs single quantum well at room temperature.
The impact of temperature and precipitation variation on drought in China in last 50 years
Authors: Zhang Da-Quan  , Zhang Lu  , Yang Jie  , Feng Guo-Lin  ,   (1)国家气候中心，中国气象局气候研究开放实验室，北京  100081; (2)兰州大学大气科学学院，兰州  730000; (3)兰州大学大气科学学院，兰州  730000；中国科学院大气物理研究所东亚区域气候-环境重点实验室，北京  100029; (4)中国科学院大气物理研究所东亚区域气候-环境重点实验室，北京  100029；国家气候中心，中国气象局气候研究开放实验室，北京  100081
Published: December 2020

Based on homogeneous temeperature, precipitation and the Palmer Drought Severity Index (PDSI) data between 1958 and 2007 of 194 stations in China, quantitative measure of impact of global warming and precipitation variation on the formation of drought in China is made through a statistical model. Dividing China into eight regions, we analyzed the importance of global warming and precipitation variations in each region respectively. Under the background of global warming, the trend of drought in north China still persists. The most probable region of drought in the next five years shows a tendendy of expansion in north China, especially in the direction to the south. Decreased precipitation is still the key factor in drought formation in most regions. However, in the north, northeast and east-northwest China, global warming plays a bigger role in drought formation.
Malware propagation in scale-free networks for the nodes with different anti-attack abilities
Authors: Song Yu-Rong  , Jiang Guo-Ping  ,   (1)南京邮电大学控制与智能技术研究中心，南京  210003; (2)南京邮电大学控制与智能技术研究中心，南京  210003；南京邮电大学自动化学院，南京  210003
Published: December 2020

Considering the nodes with different anti-attack abilities in scale-free networks，we investigated the probabilistic behaviors of malware propagation in scale-free complex networks. Using the cellular automata，we proposed a model of malware propagation in complex networks with the nodes having different anti-attack abilities. In particular，a vulnerability function related to node’s degree is firstly introduced into the model to describe the different anti-attack abilities of nodes. Then，the epidemic threshold and time evolution of malware propagation are investigated through analysis and simulation for the various vulnerability functions. The results show that different anti-attack abilities of nodes can produce significant effects on the behaviors of propagation. For example，different anti-attack abilities of nodes can change the value of epidemic propagation，and slow down the spreading speed of malware. Finally，it is pointed out that the vulnerability function is very important for adopting appropriate immunization strategies to control the malware propagation.
Instantaneous radiation energy flux of the scalar field in arbitrarily accelerating black hole with electric charge and magnetic charge
Authors: Meng Qing-Miao  , Jiang Ji-Jian  , Li Chuan-An  ,   菏泽学院物理系,菏泽  274015
Published: December 2020

Using entropy density of scalar field near event horizon in an arbitrarily accelerating black hole with electric charge and magnetic charge, we study the law for the thermal radiation of black hole and the instantaneous radiation energy flux is obtained. It is found that the thermal radiation of a black hole always satisfies the generalized Stefan-Boltzmann’s law. The proportional coefficient of generalized Stefan-Boltzmann is no longer a constant, and it becomes a dynamic coefficient that is related to the parameters of the black hole. For different dynamic black holes, the obtained generalized Stefan-Boltzmann’s dynamic proportional coefficient is different from each other, because the gravitation field and electromagnetic field around black holes is not the same.
Synchronization methods and properties of the improved chaotic system with constant Lyapunov exponent spectrum
Authors: Li Chun-Biao  , Hu Wen  ,   (1)江苏经贸职业技术学院工程技术学院，南京  210007；江苏省食品安全工程技术研究开发中心电源与系统部，南京  210007; (2)南京航空航天大学信息科学与技术学院，南京 210016
Published: December 2020

The existence of special piecewise-linear structure, global linear amplitude adjuster and phase-reverse controller in improved chaotic system with constant Lyapunov exponent spectrum contributed much to finding new synchronization methods and new adjusting parameters. According to the principle of generalized synchronization, by constructing appropriate driving system and response system, generalized synchronization of the improved chaotic system with constant Lyapunov exponent spectrum then can be achieved. By changing the parameter of response system, the complete synchronization and generalized projective synchronization can be further realized. The amplitude of the state variable of the driving system and the response system can be controlled to increase and decrease synchronously by the global linear amplitude adjuster, while the phase of certain variables can be controlled to reverse synchronously by the phase-reverser. This synchronization system dispenses with other special controllers, possesses simple structure and so can be implemented easily. Finally, the implement circuit of synchronization system is designed. It is validated by experiment simulation that the synchronization methods are feasible, the amplitude and the phase of the state variable in the synchronization system can be controlled by special parameters of the improved chaotic system.
A semiclassical analyses on the auto-ionization of lithium atom in parallel electric and magnetic fields
Authors: Deng Shan-Hong  , Gao Song  , Li Yong-Ping  , Pei Yun-Chang  , Lin Sheng-Lu  ,   山东师范大学物理与电子科学学院，济南  250014
Published: December 2020

Based on the extended closed-orbit theory with the combination recurrence induced by the nuclear core scattering，we calculate the time-dependent auto-ionization rate of lithium atoms in parallel electric and magnetic fields, and the chaotic behavior in the auto-ionization process is explained. A qualitative description of the shape of the ionizing trajectories from the nesting distinct fractal epistrophes is given.In particular, some special escape trajectories induced by core-scattering is obtained in configuration space. The escape time and the auto-ionization rate that exhibit a series of chaotic pulse train are discussed for different magnetic fields. We find that, with the increase of the magnetic field, the ionizing electron pulse train along with the corresponding ionized electron trajectories become more and more complicated, showing the sensitive dependence of the dynamic properties on the initial conditions.
Comparison between the optimal velocity model and the Nagel-Schreckenberg model
Authors: Jia Ning  , Ma Shou-Feng  ,   天津大学管理学院，系统工程研究所，天津  300072
Published: December 2020

The similarities as well as the differences of the optimal velocity model（OV model） and the Nagel-Schreckenberg model （NS model） are compared by both analytical and numerical approaches. By analyzing the rules of both models, we prove that the NS model is a discrete form model of OV model. By numerical simulations, OV model with different parameters and stochastic NS model are compared from two aspects, namely the fundamental diagram and their dynamics under open boundary conditions. The results show that these two models have very similar behaviors. However, they are different in essence, and each model has their own advantages, which makes it useful. This study provides a basis for the application and improvement of traffic flow models.
Multimode squeezed light generation in a three-plane-mirror confocal cavity
Authors: Wang Li  , Bi Si-Wen  , Wang Guo-Guo  ,   (1)中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室，西安  710119; (2)中国科学院西安光学精密机械研究所瞬态光学与光子技术国家重点实验室，西安  710119；中国科学院研究生院，北京  100049
Published: December 2020

In this paper, we propose a kind of degenerate optical parametric oscillator below threshold and use the thin crystal approximation to analyze the quantum noise reduction of the spectrum emitted from this cavity, and get the relation between the squeezing level and the pump field or the cavity detuning. We found that better squeezing level could be obtained only by properly choosing the phase of the local field, the amplitude of the pump field and the cavity detuning of the confocal cavity.
Theoretical analysis and experimental verification on speckle fields produced by the square loop aperture and circular ring aperture and their phase singularities
Authors: Liu Man  , Cheng Chuan-Fu  , Song Hong-Sheng  , Liu Gui-Yuan  , Teng Shu-Yun  ,   (1)山东师范大学物理与电子科学学院,济南  250014; (2)山东师范大学物理与电子科学学院,济南  250014；山东建筑大学理学院,济南  250101; (3)山东师范大学物理与电子科学学院,济南  250014；山东轻工业学院数理学院,济南  250353
Published: December 2020

The speckle fields and their phase singularities produced respectively by the square loop aperture and circular ring aperture are studied. It is found that the zero-contour of the real and imaginary parts occurs in the complicated tangential and intersectional situations. The tangential and intersectional points can also form phase singularities, around which the phase distribution shows the characteristics of symmetry and discontinuity，which differs from the spiral distribution around the traditional singular points formed by the zero crossings of the real and imaginary parts. The speckle particle distributions in the speckle fields produced by the square loop aperture and circular ring aperture is different from those by the traditional square aperture, and the speckle particle distributions are modulated by the scattering aperture, in stripes of horizontal or vertical outlines and circular outlines respectively. In addition, an interesting phenomenon occurs that a lot of disc-like dark regions appear in the intensity pattern of the speckle fields. We call it “light intensity dark nucleus”, whose center corresponds to a vortex with homogeneous phase distribution.
Modeling high-resolution synthetic aperture radar images with heavy-tailed distributions
Authors: Sun Zeng-Guo  , Han Chong-Zhao  ,   (1)西安交通大学电子与信息工程学院，西安  710049; (2)西安交通大学机械制造系统工程国家重点实验室，西安  710049
Published: December 2020

Statistical distributions of synthetic aperture radar （SAR） images based on central limit theorem cannot reflect the statistical characteristics of sharp peak and heavy tail of high-resolution SAR images. By using the generalized central limit theorem, the heavy-tailed distributions （heavy-tailed Rayleigh distribution for amplitude image and heavy-tailed exponential distribution for intensity image） are obtained from the symmetric stable distributions of real and imaginary parts of echoes. Taking the heavy-tailed Rayleigh distribution as an example, the algebraic tails of heavy-tailed distributions are explained as well as the statistical properties of sharp peak and heavy tail. In order to model the high-resolution SAR images with the heavy-tailed distributions, based on second-kind statistical, Characteristics the log-cumulant estimator is proposed to efficiently estimate the parameters of the heavy-tailed distributions. Modeling experiments on real SAR images demonstrate that the heavy-tailed distributions based on the generalized central limit theorem can accurately describe the sharp-peaked and heavy-tailed statistical characteristics of high-resolution SAR images.
Cytosolic calcium regulates cytoplasmic accumulation of TDP-43 through Calpain-A and Importin α3
Authors: Park Jeong Hyang , Chung Chang Geon , Park Sung Soon , Lee Davin , Kim Kyung Min , Jeong Yeonjin , Kim Eun Seon , Cho Jae Ho , Jeon Yu-Mi , Shen C-K James , Kim Hyung-Jun , Hwang Daehee , Lee Sung Bae
Published: December 2020

Cytoplasmic accumulation of TDP-43 in motor neurons is the most prominent pathological feature in amyotrophic lateral sclerosis (ALS). A feedback cycle between nucleocytoplasmic transport (NCT) defect and TDP-43 aggregation was shown to contribute to accumulation of TDP-43 in the cytoplasm. However, little is known about cellular factors that can control the activity of NCT, thereby affecting TDP-43 accumulation in the cytoplasm. Here, we identified via FRAP and optogenetics cytosolic calcium as a key cellular factor controlling NCT of TDP-43. Dynamic and reversible changes in TDP-43 localization were observed inDrosophilasensory neurons during development. Genetic and immunohistochemical analyses identified the cytosolic calcium-Calpain-A-Importin α3 pathway as a regulatory mechanism underlying NCT of TDP-43. InC9orf72ALS fly models, upregulation of the pathway activity by increasing cytosolic calcium reduced cytoplasmic accumulation of TDP-43 and mitigated behavioral defects. Together, these results suggest the calcium-Calpain-A-Importin α3 pathway as a potential therapeutic target of ALS.
Satisfação acadêmica de estudantes de ensino superior: o caso de um universitário
Authors: Rossato Vanessa Piovesan , Pinto Nelson Guilherme Machado , Müller Andressa Petry
Published: December 2020

O objetivo desse trabalho é identificar o grau de satisfação acadêmica dos alunos dos cursos de Ensino Superior de uma instituição pública do Rio Grande do Sul acerca da satisfação com o curso, oportunidades de desenvolvimento e satisfação com a instituição. Os dados foram coletados por meio de um questionário com 384 acadêmicos e analisados com o auxílio do software SPSS por meio dos testes estatísticos U Mann Whitney para até dois grupos e o de Kruskal Wallis para mais de dois grupos, a fim de verificar as diferenças de comportamento de satisfação quanto as variáveis de perfil. As questões qualitativas foram analisadas por meio da nuvem de palavras realizadas no software Word Art. Os resultados apresentaram significância para o sexo, curso, idade e se os acadêmicos trabalhavam ou não. Pelos resultados, identificou-se que homens, estudantes do curso de Economia e pessoas mais velhas possuem experiências mais satisfatórias com sua formação acadêmica. Nas questões de cunho qualitativo, identificou forte influência do professor para a satisfação com o curso, além de serem verificadas limitações entre a integração de teoria e prática nas disciplinas. Buscou-se por meio desse trabalho entender como se dá o processo de interação dos estudantes com a instituição, pois é uma questão de planejamento para as universidades.
Competências empreendedoras: um estudo com discentes do ensino médio
Authors: Lizote Suzete Antonieta , Miranda Adriane Lintener , Da Silva Samantha Guedes , Gohn Caroline
Published: December 2020

O interesse pela aprendizagem e educação empreendedoras estimula novas formas de pensar sobre o indivíduo empreendedor e o papel do ensino no seu desenvolvimento. Diante deste contexto, este estudo teve como objetivo reconhecer as competências empreendedoras que os alunos do Colégio de Aplicação da Univali (CAU) desenvolveram no Ensino Médio com a disciplina de Sociedade e Cultura. A pesquisa de natureza descritiva, teve abordagem quantitativa, sendo aplicado um questionário de autopreenchimento com base no modelo MacClelland (1973), que destaca as competências empreendedoras em 3 conjuntos (Realização, Planejamento e Poder). A população pesquisada foram os 132 alunos dos 1º, 2º e 3º anos do Ensino Médio do CAU resultando em uma amostra de 66 respondentes. Os resultados apontaram que os discentes, ao cursarem a referida disciplina, desenvolveram a competência busca de oportunidade e comprometimento no conjunto de realização ao afirmarem estarem satisfeitos com a disciplina. No planejamento, predominou o reconhecimento de oportunidades para criar produtos/serviços, desenvolvendo a competência de busca de informações. Por fim, no conjunto poder, os discentes afirmaram que acreditam no sucesso do empreendimento constituído na disciplina, ou seja, desenvolveram a autoconfiança.
An Aggressive Urothelial Carcinoma in a Horseshoe Kidney- A Case Report
Authors: Fathima Sana , Kamath Sulata Manjunath
Published: December 2020

Evidence of horseshoe kidney in Indian population is 1 in 600-800 individuals. Horseshoe kidney is predisposed to complications by virtue of its ectopic position, malrotation and associated vascular and ureteral anomalies. Incidence of Renal Cell Carcinoma (RCC) in a horseshoe kidney is same as that in general population. Other pelvic tumours, transitional tumours, Wilms tumour and carcinoids show a greater frequency. High grade urothelial carcinomas are quite rare with a few case reports available. An index case of 75 yeal old male presented with renal mass in an incidentally diagnosed horseshoe kidney on radiologic imaging. The case has been highlighted due to its poorly differentiated tumour morphology and aggressive nature. Further, immunohistochemistry was done to arrive at a correct diagnosis for appropriate treatment. The tumour cells showed positivity for Cytokeratin 7 (CK 7) and CK 5/6. They were negative for p63, PAX-8 (Paired-box gene 8). Also, it is technically difficult to excise large-sized renal mass in an anomalous kidney.
Complications Associated with Osmotic Therapy in Acute Stroke Patients- A Prospective Longitudinal Observational Study
Authors: Rackimuthu Sudhan , Ishwara Pawan Raj Pulu , Suresh Sucharitha
Published: December 2020

Introduction: Mannitol is one of the most frequently used drugs to treat cerebral oedema resulting from ischemic and haemorrhagic strokes. Mannitol administration is associated with complications such as Acute Kidney Injury (AKI) and electrolyte imbalance. Aim: To study effect of mannitol therapy on electrolyte levels and renal function in acute stroke patients. Materials and Methods: The present prospective longitudinal observational study was carried out from January 2019 till September 2019 in Father Muller Medical College, Mangalore, India. After taking informed consent, patients with acute stroke who received mannitol were recruited into the study. Nature of the stroke, presence of comorbidities and dosage of mannitol given were recorded. Serum electrolytes, Serum urea and creatinine were recorded at admission and on fifth day. Serum urea was measured by enzymatic photometric method using urease and glutamate dehydrogenase and serum creatinine was measured by Jaffe’s kinetic method. Comparison of data among different groups was performed using student t-test, ANOVA test, Mann-whitney test and Pearson test. The p-values <0.05 were taken as statistically significant. Results: Total of 72 patients were included in the study. Mean age was 57.7±14.6 years and male: female ratio was 2.27:1. Of the total study subjects, 16 suffered from diabetes (22.22%), 40 from hypertension (55.55%). Ischemic stroke was seen in 41.66% patients and haemorrhagic stroke was seen in 58.33% of the patients. The dose of mannitol administered to all the patients was less than 1 gram/kg/day (low dose mannitol). Cumulative dose of mannitol was 180±177.3 grams. Serum sodium levels were significantly lower on fifth day compared to admission (p-value 0.030) whereas serum potassium and chloride levels were not significantly changed during therapy. There was statistically significant elevation in serum urea levels from admission to fifth day (p-value <0.001) whereas creatinine levels were not significantly altered. Total cumulative dose was compared to serum electrolyte levels and urea and creatinine at admission and fifth day and no significant changes were found. On analysing comorbidities, electrolyte fluctuations were more common in diabetics and Chronic Kidney Disease (CKD) patients whereas renal function parameters were abnormal in diabetics, CKD and hypertensive patients. None of the patients needed any corrective measures to treat the dyselectrolytemias or altered renal function. Conclusion: Low dose mannitol therapy does not produce any significant electrolyte or renal function abnormality in patients with acute stroke. Careful monitoring may be required while treating patients with additional comorbidities.
Midbrain Pons Ratio- A Diagnostic Tool for Progressive Supranuclear Palsy
Authors: Jabir Mappilaveetil Sayed , Haris Anjamparuthikal Aboobakar
Published: December 2020

Introduction: Progressive Supranuclear Palsy (PSP) is a Parkinsonism plus syndrome. PSP has different clinical features, it is unresponsive to levodopa and have poor prognosis compared to classical Parkinson’s Disease (PD). However, in clinical practice accurate diagnosis of parkinsonian syndromes are difficult especially when the patient presents early during the course of illness. Diagnosis of each condition is important since it affects patient’s management, rehabilitation and prognosis. Magnetic Resonance Imaging (MRI) is especially useful tool in parkinsonian syndromes, since it identifies changes produced by the neurodegeneration. Rostral midbrain atrophy is seen in PSP. Midbrain pons ratio helps to identify the atrophy involving midbrain, thus helps in differentiating PSP from other causes of parkinsonism. Aim: To investigate the utility of midbrain diameter and midbrain pons ratio in mid-sagittal sections of MRI for differentiation of PSP from other neurodegenerative parkinsonism. Materials and Methods: This was a cross-sectional study conducted in Department of Neurology, Government Medical College, Kottayam, Kerala, India. Of all the patients who presented with clinical features of Parkinsonism, 124 patients who met the inclusion criteria were selected for the study. Comparison was made between the values obtained in clinically diagnosed patients with PSP (n=30), PD (n=30), Multiple System Atrophy (MSA) (n=30), Corticobasal Degeneration (CBD) (n=4) and normal Controls (n=30). These patients underwent MRI and the mid-sagittal T1 weighted MRI images were obtained; the diameter of midbrain and pontine base as well as midbrain-to-pons ratio was calculated. Quantitative analysis of five groups were done using Analysis of Variance (ANOVA) with post-hoc Tukey correction. Results: Mean age of patients in PSP was 59.47±3.86 years. The mean midbrain diameter was found to be lower in PSP, measuring 7.8±0.83 mm (p<0.001) with reduction of the midbrain-to-pons ratio. The mean midbrain pons ratio was found to be lower in PSP, measuring 0.45±0.03 in comparison with the other parkinsonian syndromes (p<0.001). Conclusion: Midbrain pons ratio and midbrain diameter in MRI is a simple measurement for differentiating PSP from other degenerative parkinsonian syndromes.
Halophilic to mesophilic adaptation of ubiquitin‐like proteins
Authors: Li Quan , Li Mengqing , Li Cong , Li Xinxin , Lu Chenghui , Tu Xiaoming , Zhang Zhiyong , Zhang Xuecheng
Published: December 2020

Elucidating how proteins adapt from halophilic to mesophilic environments will enable a better understanding of protein evolution and folding. In this study, by directed evolution and site‐directed mutagenesis of the halophilic ubiquitin‐like protein (ULP) Samp2, we find that substitution of the prebiotic amino acid Asp31 by Gly is uniquely effective in the mesophilic adaptation of ULP. Sequence analysis shows that substitution of Asp/Glu in halophilic ULPs by Gly in mesophilic ULPs has higher occurrence than other substitutions, supporting the unique role of the substitution in the mesophilic adaptation of ULP. Molecular dynamic simulations indicate that the mesophilic adaptation might result from the effect of the substitution on the conformational flexibility of ULP.
Penalties in Chemometrics
Authors: Eilers Paul H.C.
Published: December 2020

A penalty is a simple device to push the solution of a regression model in a desired direction. A penalty can achieve smoothness, or it can remove singularities. Both types of penalties are presented. Important applications of roughness penalties are noise reduction and trend estimation. Size penalties have their origin in ridge regression for multivariate calibration. It is shown that roughness penalties are more effective in this application.

A penalty comes with a tuning parameter to set its influence. To optimize the penalty, cross‐validation is effective. In a regression model it can be implemented in an efficient way. Several examples are provided.
Mobile Chromatographs and Spectrometers for the Analysis of Chemical Warfare Agents
Authors: Witkiewicz Zygfryd , Wardencki Waldemar , Neffe Sławomir
Published: December 2020

This article describes the technological state of readiness regarding mobile chromatographs and spectrometers and their applicability for the analysis of chemical warfare agents (CWAs), degradation products, simulants, and precursors. Application of chromatographic techniques and instruments, which are useful for the screening and analysis of Chemical Weapons Convention (CWC)‐related chemicals, is described. Proper choice of mobile equipment and its applicability for detection of CWAs are discussed. Various miniaturized detectors and analytical procedures are described. The analytical techniques and advanced software for large amount of analytical data management are important factors when performing the on‐site analysis for security and forensic needs. The advantages and disadvantages of mobile instruments in comparison with the laboratory equipment are presented.
A review on medical imaging synthesis using deep learning and its clinical applications
Authors: Wang Tonghe , Lei Yang , Fu Yabo , Wynne Jacob F. , Curran Walter J. , Liu Tian , Yang Xiaofeng
Published: December 2020

This paper reviewed the deep learning‐based studies for medical imaging synthesis and its clinical application. Specifically, we summarized the recent developments of deep learning‐based methods in inter‐ and intra‐modality image synthesis by listing and highlighting the proposed methods, study designs, and reported performances with related clinical applications on representative studies. The challenges among the reviewed studies were then summarized with discussion.
Encouraging trends from NSDUH at risk as a result of tumultuous 2020
Authors: Enos Gary
Published: December 2020

Even as federal officials last summer were releasing substance use data suggesting a continuation of mostly positive trends in the National Survey on Drug Use and Health (NSDUH), a preoccupation with the potential impacts of COVID‐19 on substance use was overshadowing encouraging 2019 numbers for opioids and alcohol.
Polyphenol‐Induced Adhesive Liquid Metal Inks for Substrate‐Independent Direct Pen Writing
Authors: Rahim Md. Arifur , Centurion Franco , Han Jialuo , Abbasi Roozbeh , Mayyas Mohannad , Sun Jing , Christoe Michael J. , Esrafilzadeh Dorna , Allioux Francois‐Marie , Ghasemian Mohammad B. , Yang Jiong , Tang Jianbo , Daeneke Torben , Mettu Srinivas , Zhang Jin , Uddin Md Hemayet , Jalili Rouhollah , Kalantar‐Zadeh Kourosh
Published: December 2020

Surface patterning of liquid metals (LMs) is a key processing step for LM‐based functional systems. Current patterning methods are substrate specific and largely suffer from undesired imperfections—restricting their widespread applications. Inspired by the universal catechol adhesion chemistry observed in nature, LM inks stabilized by the assembly of a naturally abundant polyphenol, tannic acid, has been developed. The intrinsic adhesive properties of tannic acid containing multiple catechol/gallol groups, allow the inks to be applied to a variety of substrates ranging from flexible to rigid, metallic to plastics and flat to curved, even using a ballpoint pen. This method can be further extended from hand‐written texts to complex conductive patterns using an automated setup. In addition, capacitive touch and hazardous heavy metal ion sensors have been patterned, leveraging from the synergistic combination of polyphenols and LMs. Overall, this strategy provides a unique platform to manipulate LMs from hand‐written pattern to complex designs onto the substrate of choice, that has remained challenging to achieve otherwise.
Tumor Microenvironment‐“AND” Near‐Infrared Light‐Activated Coordination Polymer Nanoprodrug for On‐Demand CO‐Sensitized Synergistic Cancer Therapy
Authors: Sun Panpan , Jia Le , Hai Jun , Lu Siyu , Chen Fengjuan , Liang Kun , Sun Shihao , Liu Hanwen , Fu Xu , Zhu Yanhong , Wang Baodui
Published: December 2020

Carbon monoxide (CO) as an emerging treatment holds great promise for inducing the apoptosis of cancer cells. Here coordination assembled strategy is first reported for synthesis of Cu(II)‐flavone coordination polymer (NCu‐FleCP) CO nanoprodrug that is stable in normal physiological conditions, and yet readily reduces to small size prodrug complex and releases CO on demand under glutathione (GSH) and near infrared (NIR) light. Specifically, after uptaking by cancer cells, local GSH attacked coordination bond within NCu‐FleCP, resulting in the release of Cu(I) and free Fle. The CC bond of Fle is cleavage under NIR light to release CO for gas therapy, and Cu(I) reacts with local H2O2 through Fenton like reaction to generate hydroxyl radicals (•OH) for chemodynamic therapy. Detailed in vitro and in vivo experiments demonstrate that the CO prodrug system in generating a sufficient quantity of CO and •OH offers remarkable destructive effects against cancer cells without causing toxicity to surrounding normal tissues. The study provides a solid foundation to develop smart coordination polymer CO prodrugs with on‐demand CO release, enhanced permeability and retention effect, and biodegradability for multimodal synergistic therapy.
Emerging Light‐Emitting Materials for Photonic Integration
Authors: Liu De‐Sheng , Wu Jiang , Xu Hongxing , Wang Zhiming
Published: December 2020

The arrival of the information explosion era is urging the development of large‐bandwidth high‐data‐rate optical interconnection technology. Up to now, the biggest stumbling block in optical interconnections has been the lack of efficient light sources despite significant progress that has been made in germanium‐on‐silicon (Ge‐on‐Si) and III‐V‐on‐silicon (III‐V‐on‐Si) lasers. 2D materials and metal halide perovskites have attracted much attention in recent years, and exhibit distinctive advantages in the application of on‐chip light emitters. Herein, this Progress Report reviews the recent progress made in light‐emitting materials with a focus on new materials, i.e., 2D materials and metal halide perovskites. The report briefly introduces the current status of Ge‐on‐Si and III‐V‐on‐Si lasers and discusses the advances of 2D and perovskite light‐emitting materials for photonic integration, including their optical properties, preparation methods, as well as the light sources based on these materials. Finally, challenges and perspectives of these emerging materials on the way to the efficient light sources are discussed.
Improving the Sensitivity of Planar Fabry–Pérot Cavities via Adaptive Optics and Mode Filtering
Authors: Czuchnowski Jakub , Prevedel Robert
Published: December 2020

Fabry–Pérot (FP) cavities are fundamental and ubiquitous optical elements frequently used in various sensing applications. Here, the authors introduce a general theoretical framework to study arbitrary light–cavity mode interactions for planar FPs and show how optical aberrations, intrinsic to the interrogating beam or due to imperfect cavities, reduce optical sensitivity by exciting higher‐order spatial modes in the cavity. It is found that particular Zernike aberrations play a dominant role in sensitivity degradation, and that the general loss of sensitivity can be significantly recovered by appropriate wavefront correction or mode filtering. The authors then demonstrate their theoretical findings also experimentally and show that in practice the sensitivity of realistic planar FP micro‐cavity sensors can be improved up to threefold by a synergistic combination of adaptive optics and passive mode filtering.
COVID‐19 and fresh produce markets in the United States and China
Authors: Çakır Metin , Li Qingxiao , Yang Xiaoli
Published: December 2020

This paper examines the impact of COVID‐19 on fruits and vegetable prices in the United States and China in a difference‐in‐differences framework. Our main results show differing impacts of the pandemic on the U.S. and Chinese wholesale prices. We conclude that despite the unprecedented disruptions, the U.S. produce industry remained intact. However, the long‐run effects could be mixed. We conjecture that the industry would stay resilient in the long run by having gained practical know‐how. Nevertheless, potential structural changes, such as changing household expenditure patterns due to income loss and increasing concentration in the food service market, could hurt the industry.
Self‐Driven Multistep Quantum Dot Synthesis Enabled by Autonomous Robotic Experimentation in Flow
Authors: Abdel-Latif Kameel , Epps Robert W. , Bateni Fazel , Han Suyong , Reyes Kristofer G. , Abolhasani Milad
Published: December 2020

Identifying the optimal formulation of emerging inorganic lead halide perovskite quantum dots (LHP QDs) with their vast colloidal synthesis universe and multiple synthesis/postsynthesis processing parameters is a challenging undertaking for material‐ and time‐intensive, batch synthesis strategies. Herein, a modular microfluidic synthesis strategy, integrated with an artificial intelligence (AI)‐guided decision‐making agent for intelligent navigation through the complex colloidal synthesis universe of LHP QDs with 10 individually controlled synthesis parameters and an accessible parameter space exceeding 2 × 107, is introduced. Utilizing the developed autonomous microfluidic experimentation strategy within a global learning framework, the optimal formulation of LHP QDs is rapidly identified through a two‐step colloidal synthesis and postsynthesis halide exchange reaction, for 10 different emission colors in less than 40 min per desired peak emission energy. Using two in‐series microfluidic reactors enables continuous bandgap engineering of LHP QDs via in‐line halide exchange reactions without the need for an intermediate washing step. Using an inert gas within a three‐phase flow format enables successful, self‐synchronized continuous delivery of halide salt precursor into moving droplets containing LHP QDs, resulting in accelerated closed‐loop formulation optimization and end‐to‐end continuous manufacturing of LHP QDs with desired optoelectronic properties.
How specialized is a soil specialist? Early life history responses of a rare Eriogonum to site‐level variation in volcanic soils
Authors: McClinton Jamey D. , Parchman Thomas L. , Torrence Kathleen L. , Verburg Paul S. , Leger Elizabeth A.
Published: December 2020

PREMISE

Understanding edaphic specialization is crucial for conserving rare plants that may need relocation due to habitat loss. Focusing on Eriogonum crosbyae, a rare soil specialist in the Great Basin of the United States, we asked how site‐level variation among volcanic soil outcrops affected plant growth and population distribution.

METHODS

We measured emergence, survival, size, and biomass allocation of E. crosbyae seedlings planted in soils collected from 42 outcrops of actual and potential habitat. We also measured phenotypic variation in the wild, documented abiotic and biotic components of E. crosbyae habitat, re‐surveyed Nevada populations, and evaluated occupancy changes over time.

RESULTS

Plants responded plastically to edaphic variation, growing larger and allocating relatively more to aboveground tissues in soils with greater nutrient availability and growing smaller in soils higher in copper in the field and the greenhouse. However, the chemical and physical soil properties we measured did not predict site occupancy, nor was plant phenotype in the greenhouse different when plants were grown in soils from sites with different occupation status. We observed occupation status reversals at five locations.

CONCLUSIONS

Eriogonum crosbyae performed well in soils formed on hydrothermally altered rocks that are inhospitable to many other plants. Extirpation/colonization events observed were consistent with metapopulation dynamics, which may partially explain the patchy distribution of E. crosbyae among outcrops of potential habitat. While soil properties did not predict site occupancy, early life stages showed sensitivity to soil variation, indicating that seedling dynamics may be important to consider for the conservation of this soil specialist.
First patient with mosaic NOTCH3 gene pathogenic variant. Unrevealed mosaicisms and importance of their detection
Authors: Moreno‐García Marta , Arteche‐López Ana Rosa , Álvarez‐Mora María Isabel , Palma Milla Carmen , Quesada Espinosa Juan Francisco , Lezana Rosales José Miguel , Sánchez Calvín María Teresa , Gómez Manjón Irene , Gómez Rodríguez María José , Mendez‐Guerrero Antonio , Villarejo‐Galende Alberto
Published: December 2020

Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an inherited small vessel disease caused predominantly by pathogenic variants in NOTCH3 gene. Neither germline nor somatic mosaicism has been previously published in NOTCH3 gene. CADASIL is inherited in an autosomal dominant manner; only rare cases have been associated with de novo pathogenic variants. Mosaicism is more common than previously thought because mosaic variants often stay unrevealed. An apparently de novo variant might actually be a consequence of a parental mosaicism undetectable with Sanger sequencing, especially in the case of low grade mosaicism. Parental testing by sensitive tools like deep targeted next‐generation sequencing (NGS) analysis could detect cases of unrevealed medium or low level mosaicism in patients tested by Sanger sequencing. Here, we report the first patient with mosaic NOTCH3 gene pathogenic variant to our knowledge; the allelic fraction in the leucocyte DNA was low (13%); the pathogenic variant was inhered by his two daughters. The patient was diagnosed by deep targeted NGS analysis after studying his two affected daughters. This report highlights the importance of parental testing by sensitive tools like deep targeted NGS analysis. Detection of mosaicism is of great importance for diagnosis and adequate family genetic counseling.
NIR‐II pH Sensor with a FRET Adjustable Transition Point for In Situ Dynamic Tumor Microenvironment Visualization
Authors: Zhao Mengyao , Wang Jianbo , Lei Zuhai , Lu Lingfei , Wang Shangfeng , Zhang Hongxin , Li Benhao , Zhang Fan
Published: December 2020

Monitoring the pH in tumor lesions provides abundant physiological information. However, currently developed pH sensors only achieve sensitive detection in the settled response region around the pH transition point (pHt). To realize tumor pH monitoring with high sensitivity within a wider response region, reported here are serial pHt adjustable sensors (pTAS) that simply regulate the component ratio of second near‐infrared (NIR‐II) emission aza‐BODIPY (NAB) donor and pH sensitive rhodamine‐based pre‐acceptor (NRh) in Förster resonance energy transfer system. Combining the pH response regions of pTAS, a twofold widened pH detection range (6.11–7.22) is obtained compared to the pHt settled sensor (6.38–6.94). With an adjustable pHt, in vivo tumor pH increase and decrease processes could be dynamically visualized through dual‐channel ratiometric bioimaging within the NIR‐II window, with a coefficient of variation under 1 % compared to the standard pH meter.
Artificial Heterointerfaces Achieve Delicate Reaction Kinetics towards Hydrogen Evolution and Hydrazine Oxidation Catalysis
Authors: Qian Qizhu , Zhang Jihua , Li Jianming , Li Yapeng , Jin Xu , Zhu Yin , Liu Yi , Li Ziyun , El‐Harairy Ahmed , Xiao Chong , Zhang Genqiang , Xie Yi
Published: December 2020

Electrochemical water splitting for H2 production is limited by the sluggish anode oxygen evolution reaction (OER), thus using hydrazine oxidation reaction (HzOR) to replace OER has received great attention. Here we report the hierarchical porous nanosheet arrays with abundant Ni3N‐Co3N heterointerfaces on Ni foam with superior hydrogen evolution reaction (HER) and HzOR activity, realizing working potentials of −43 and −88 mV for 10 mA cm−2, respectively, and achieving an industry‐level 1000 mA cm−2 at 200 mV for HzOR. The two‐electrode overall hydrazine splitting (OHzS) electrolyzer requires the cell voltages of 0.071 and 0.76 V for 10 and 400 mA cm−2, respectively. The H2 production powered by a direct hydrazine fuel cell (DHzFC) and a commercial solar cell are investigated to inspire future practical applications. DFT calculations decipher that heterointerfaces simultaneously optimize the hydrogen adsorption free energy (ΔGH*) and promote the hydrazine dehydrogenation kinetics. This work provides a rationale for advanced bifunctional electrocatalysts, and propels the practical energy‐saving H2 generation techniques.
Transformable Honeycomb‐Like Nanoassemblies of Carbon Dots for Regulated Multisite Delivery and Enhanced Antitumor Chemoimmunotherapy
Authors: Hou Lin , Chen Dandan , Wang Ruiting , Wang Ruibing , Zhang Huijuan , Zhang Zhenzhong , Nie Zhihong , Lu Siyu
Published: December 2020

Tumor fibrotic stroma forms complex barriers for therapeutic nanomedicine. Although nanoparticle vehicles are promising in overcoming biological barriers for drug delivery, fibrosis causes hypoxia, immunosuppression and limited immunocytes infiltration, and thus reduces antitumor efficacy of nanosystems. Herein, we report the development of cancer‐associated fibroblasts (CAFs) responsive honeycomb‐like nanoassemblies of carbon dots (CDs) to spatially program the delivery of multiple therapeutics for enhanced antitumor chemoimmunotherapy. Doxorubicin (DOX) and immunotherapeutic enhancer (Fe ions) are immobilized on the surface of CDs, whereas tumor microenvironment modifier (losartan, LOS) is encapsulated within the mesopores. The drugs‐loaded nanoassemblies disassociate into individual CDs to release LOS to mitigate stroma and hypoxia in response to CAFs. The individual CDs carrying DOX and Fe ion efficiently penetrate deep into tumor to trigger intensified immune responses. Our in vitro and in vivo studies show that the nanoassemblies exhibit effective T cells infiltration, tumor growth inhibition and lung metastasis prevention, thereby providing a therapeutic platform for desmoplasia solid tumor.
Alkyne 1,1‐Hydroboration to a Reactive Frustrated P/B‐H Lewis Pair
Authors: Škoch Karel , Daniliuc Constantin G. , Kehr Gerald , Erker Gerhard
Published: December 2020

The Mes2P‐C≡C‐SiMe3 alkyne reacts with the borane H2B‐Fmes by means of a rare 1,1‐hydroboration reaction to give an unsaturated C2‐bridged frustrated P/B‐H Lewis pair. Most of its reactions are determined by the presence of the B‐H functionality at the FLP function and the activated connecting carbon‐carbon double bond. It reduces carbon monoxide to the formyl stage. With nitriles it reacts in an extraordinary way: it undergoes a reaction sequence that eventually results in the formation of a P‐substituted dihydro‐1,2‐azaborole derivative. Several similar examples were found. In one case a P‐ylide was isolated that was related to an intermediate of the reaction sequence. It subsequently opened in an alternative way to give an alkenyl borane product.
Pentaerythritol derived phosphorous based bicyclic compounds as promising flame retardants for thermoplastic polyurethane films
Authors:   Shikha, Meena Mahipal , Jacob Josemon
Published: December 2020

Imparting flame retardancy without melt dripping in thermoplastic polyurethane (TPU) is a challenging task. In the current work, a series of pentaerythritol derived phosphorous based flame retardants (FRs labeled FR1, FR2, FR3, and FR4) were synthesized, and their suitability for TPU thin films (<100 micron) was explored. Vertical flammability tests revealed that a blend of FR2 and TPU at 2% phosphorous content exhibited excellent flame suppression and complete stoppage of melt dripping whereas samples prepared from FR1 showed reduced melt drips. In comparison to FR1 and FR2, FR3 and FR4 manifested excessive nonflamed melt drips, which helps in removal of heat from the combustion cycle and self‐extinguishment. The limiting oxygen index value of flame retardant (FRTPU) blends reached up to 33.5% compared to 19% for pure TPU. Thermogravimetric analysis and scanning electron microscopy studies suggest that blends of TPU with FR1 and FR2 display high char residue and condensed phase mechanism, whereas FR3 and FR4 blends show low char residue, working in the gas phase and by the removal of polymer from flame zone through melt dripping phenomena.