bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics between disaggregates of governance and stock market performance in selected South Asia countries
Authors: Ahmed Khalid , Khan Bareerah , Ozturk Ilhan
Published: July 2020

This study explores the dynamics between disaggregated factors of governance and stock market development for the panel of selected South Asian countries (i.e., Bangladesh, India, Pakistan and Sri Lanka). Using newly developed data for disaggregates of governance with annual frequency between 1996 and 2014, this study pioneers in South Asian context. Doing so, this study incorporates dynamic panel data technique pool mean group estimation for robust and policy oriented outcomes. The empirical results show that three indicators of governance (control of corruption, accountability and rule of law) have a positive and statistically significant impact on stock market development. The results of long‐run estimations are homogenous across the countries but, the short‐run estimates, and the speed of adjustment towards the long‐run equilibrium are found to be heterogeneous. It could be due to volatility effect of governance in each cross section country. From the policy perspective, the study concludes that the institutional quality and governance are the significant factors on market capitalization in the panel countries. The institutional factors (i.e., control of corruption, accountability and rule of law) support stock market development through high market capitalization, strengthens investor's confidence for long term investment in the countries.
The impact of tunnelling on financial distress and resolution: Evidence from listed firms in China
Authors: He Yu , Xu Lei , Yang Minhua
Published: July 2020

We examine the impact of tunnelling on financial distress in Chinese stock markets, where the agency problem is common due to the weak legal system protecting minority shareholders' interests. Investigating the widespread financial distress among listed firms during the time period 1999–2015, we find that tunnelling is a determinant of financial distress–tunnelling not only leading to financial distress but also prohibiting distress recovery. Regulatory improvements aiming to reduce tunnelling behaviour contribute to the resolution of financial distress, but there is still room to improve. Our results show that state ownership has limited influence on firm operation before financial distress but tends to benefit recovery from periods of distress, which depicts the market economy mechanism in China. Our findings are robust to the potential endogeneity issue and various measures of financial distress.
Testing the Δ‐∑ hypothesis in the suboptimal choice task: Same delta with different probabilities of reinforcement
Authors: González Valeria V. , Macías Alejandro , Machado Armando , Vasconcelos Marco
Published: July 2020

In a concurrent‐chain procedure, pigeons choose between 2 initial‐link stimuli; one is followed by terminal link stimuli that signal reliably whether food will be delivered after a delay; the other is followed by terminal link stimuli that do not signal whether food will be delivered after the delay. Pigeons prefer the former alternative even when it yields a lower overall probability of food. Recently, we proposed the Delta‐Sigma (∆‐∑) hypothesis to explain the effect: Preference depends on the difference (∆) between the reinforcement probabilities associated with the terminal link stimuli, and the overall probability of reinforcement (∑) associated with the alternative. The hypothesis predicts that, for constant ∑, animals should prefer alternatives with greater ∆ values regardless of the specific probabilities of reinforcement that determine ∆. In 2 experiments, we tested this prediction by comparing a ∆ = .5 against a ∆ = 0 alternative, with the former obtained with different pairs of reinforcement probabilities across conditions. The results supported the hypothesis when the 2 probabilities defining ∆ were significantly greater than 0, but not when one of them was close to 0. The results challenge our theoretical accounts of suboptimal choice and the variables considered to determine pigeons’ preference.
Characterization of RDX and HMX explosive adduct ions using ESI FT‐ICR MS
Authors: Lee Jihyeon , Kim Min Sun , Kim Hyun Sik , Choe Yoong‐Kee , Cho Soo Gyeong , Goh Eun Mee , Kim Jeongkwon
Published: July 2020

Investigation of two common explosives such as cyclonite (RDX) and cyclotetramethylenetetranitramine (HMX) using a mass spectrometer with ultrahigh resolution and accuracy has not been comprehensively performed. Here, ultrahigh mass accuracy 15‐T Fourier transform–ion cyclotron resonance mass spectrometry (FT‐ICR MS) spectra were utilized to comprehensively characterize the adduct ions of RDX and HMX. Two different ionization sources such as a conventional electrospray ionization (ESI) source and a chip‐based static nano‐ESI source were used to investigate the adduct ions of RDX and HMX. The ESI‐MS analyses of two explosives in negative ion mode provide some adduct ions of RDX and HMX even without prior addition of their corresponding anions. A total of six types of adduct ion were characterized: [M + Cl]−, [M + HCOO]−, [M + NO2]−, [M + CH3COO]−, [M + NO3]−, and [M + C3H5O3]−, where M is either RDX or HMX. The ultrahigh accuracy of the 15‐T FT‐ICR MS was utilized to distinguish two closely spaced peaks representing the monoisotopic [M + NO2]− and second isotopic [M + HCOO]− ions, thereby enabling the discovery of a [M + NO2]− adduct ion in the ESI analysis of RDX or HMX. [M + NO2]− and [M + CH3COO]− adduct ions were only observed when using a static nano‐ESI source. It is the first report explaining the discovery of [M + NO2]− adduct ion in the ESI‐MS analyses of RDX and HMX.
Clinical validation of an immunochromatographic SARS‐Cov‐2 IgM/IgG antibody assay with Japanese cohort
Authors: Kaneko Shun , Nukui Yoko , Arashiro Takeshi , Aiso Yoshibumi , Sugii Maya , Hadano Yoshiro , Nagata Kaoru , Taki Reiko , Ueda Ken , Hanada Satoko , Suzaki Shinichiro , Harada Naoshige , Yamaguchi Yoshimi , Nakanishi Hiroyuki , Kurosaki Masayuki , Nagasawa Masayuki , Izumi Namiki
Published: July 2020

Background

The coronavirus disease 2019 (COVID‐19) has become a major health threat. To overcome COVID‐19, appropriate diagnosis methods are urgently needed. The aim of this study was to clinically evaluate the colloidal gold immunochromatography assay for SARS‐Cov‐2 IgM/IgG antibody (Ab).

Methods

Patients confirmed COVID‐19 (n = 51) were recruited prospectively from the Musashino Red Cross hospital and Tokyo Medical and Dental University Medical Hospital, between March and May 2020. And the analytical specificity was assessed with serum samples of patients without COVID‐19 (n = 100) collected between August to September 2019 before SARS‐CoV‐2 was first reported in China.

Results

Among COVID‐19 patients, a total of 87 serum samples were tested for SARS‐Cov‐2 IgM/IgG Ab assay. IgM was detected 71.0 %, 86.9 %, and 83.3 % at day8‐14, 15‐28, >29 after symptom onset and IgG was detected in 81.6 %, 87.0 %, and 94.4 %, respectively. The sensitivity of IgM and IgG Ab after day8 assay was significantly higher than before day7, respectively (p=0.0016, 0.0003). There were no positive results in 100 serum samples from patients without COVID‐19.

Conclusion

The SARS‐Cov‐2 IgM/IgG Ab assay had 79.7% / 86.1% sensitivity (the 8 days after from onset) and 100% specificity in this population.
The association of interleukin‐6 value, interleukin inhibitors, and outcomes of patients with COVID‐19 in New York City
Authors: Maeda Tetsuro , Obata Reiichiro , Rizk DO Dahlia , Kuno Toshiki
Published: July 2020

Since cytokine release syndrome with elevation of interleukin‐6 (IL‐6) is considered to be associated with severe cases of coronavirus disease 2019 (COVID‐19); IL‐6 inhibitors, such as tocilizumab, are expected to be effective for its treatment. This was a retrospective study using a consecutive cohort of 224 patients hospitalized with COVID‐19 in March 2020. Patients were divided into those admitted to the intensive care unit (ICU group) and those not (no ICU group), and clinical data including usage of tocilizumab were compared. Correlation between IL‐6 value at admission and at peak, and tocilizumab use, as well as clinical outcomes were also investigated. The ICU group had higher rates of pre‐existing comorbidities such as hypertension, diabetes, and coronary disease, and higher IL‐6 than no ICU group (all P < .05). Age, peak IL‐6, and peak d‐dimer were significant predictors of in‐hospital mortality (1.05 [1.01‐1.09], P = .012; 1.001 [1.000‐1.002], P = .002; 1.10 [1.03‐1.18], P = .008). Receiver operating characteristics curve showed higher predictability of in‐hospital mortality with IL‐6 at peak than others (area under curve; IL‐6 at peak: 0.875 [0.87‐0.942], IL‐6 at admission: 0.794 [0.699‐0.889], d‐dimer at peak 0.787 [0.690‐0.883], d‐dimer at admission 0.726 [0.625‐0.827]). Incidence of fungal infections was significantly higher in patients who were given tocilizumab than those who were not (13.0% vs 1.1%, P < .001). Notably, tocilizumab did not affect in‐hospital mortality after adjustment including IL‐6 (odds ratio [95% confidential interval]: 1.00 [0.27‐3.72, P = .998]). Age, peak IL‐6, and peak d‐dimer levels were significant predictors of in‐hospital mortality. Tocilizumab did not decrease in‐hospital mortality in our cohort.
Use of Home Enteral Nutrition in Malnourished Post‐Bariatric Surgery Patients
Authors: Velapati Saketh R. , Schroeder Sarah E. , Schroeder Darrell R. , Buttar Navtej S. , Mohamed Elfadil Osman , Hurt Ryan T. , Mundi Manpreet S.
Published: July 2020

Background

Bariatric surgery is by far the most effective treatment option available for successfully achieving and maintaining weight loss in the obese population, but it can also be associated with complications that lead to malnutrition. There is limited data on how enteral nutrition (EN) can be used to provide nutrition support in such cases.

Methods

Retrospective review of our Home Enteral Nutrition (HEN) database was conducted from February 2013 to April 2018 to identify patients who received HEN because of bariatric surgery–related complication.

Results

During the study period, 72 patients (86% female, mean age 50.3 ± 11.6 years) initiated HEN because of bariatric surgical complication. Most common bariatric surgery was Roux‐en‐Y (74%) and most common indication for HEN was malnutrition/failure to thrive (33%). HEN was most commonly provided through nasojejunal feeds and resulted in an average increase in body weight and body mass index from 74.8 kg and 26.5, respectively, before HEN to 76.9 kg and 27.2, respectively, at the end of the HEN period. Through HEN, patients received 22.2 ± 7.9 kcal/kg/d and 1.0 ± 0.3 g/kg/d protein, meeting 94% ± 17% of their energy goals and 95% ± 29% of their protein goals. Vitamin deficiencies were noted in 69% of patients at the time of HEN initiation, which improved to 10% after enteral feeds and appropriate vitamin supplementation.

Conclusion

HEN is safe and effective in treating malnutrition and vitamin deficiencies that might occur as a complication of bariatric surgery, leading to avoidance of parenteral nutrition support in most cases.
Congenital Short‐Bowel Syndrome: Clinical and Genetic Presentation in China
Authors: Wang Ying , Chen Shanshan , Yan Weihui , Lu Lina , Tao Yijng , Xiao Yongtao , Cai Wei
Published: July 2020

Background

Congenital short‐bowel syndrome (CSBS) is a rare disorder characterized by retardation of intestinal development. However, it is still not well recognized at present. In this study, the etiological, clinical, and genetic characteristics of CSBS in China were analyzed.

Methods

Nine infants with CSBS were recruited. Full‐thickness biopsy findings were evaluated by histopathology. Whole‐exome sequencing was performed to identify mutations in patients and their family members. All patients were followed up at >1 year of age.

Results

Six of 9 infants had malrotation, and 2 patients had intestinal atresia. The average total small‐bowel length was 51.7 (40–75) cm. Coxsackie and adenovirus receptor‐like membrane protein (CLMP) mutations were found in 5 patients and were related to decreases in ileal goblet cells and mucous secretion. Among these 5 patients, 3 shared the same mutation (c. 206G>A p.R69H), 1 patient had an exon 3–5 deletion, and 1 patient had the C.655T>G, p.Cys219Gly, and C.389‐2A>C. Another case carried a loss‐of‐function mutation in filamin A (FLNA). In the other 3 patients, no pathogenic mutations in genes related to intestinal development were found. The rate of catheter‐related bloodstream infection was 4.3 per 1000 catheter days, and intestinal failure–associated liver disease (IFALD) was 77.8%. The median follow‐up duration was 24.1 months. Eight patients were weaned off parenteral nutrition (PN). Six patients still exhibited malnutrition during follow‐up.

Conclusions

Infants with CSBS often need long‐term PN and remain at risk of SBS‐related complications. CLMP and FLNA mutations are associated with CSBS in the Chinese population.
AVM nuclear glass/steel/claystone system altered by Callovo–Oxfordian poral water with and without cement–bentonite grout at 70°C
Authors: Carriere Charly , Neff Delphine , Martin Christelle , Tocino Florent , Delanoë Alexis , Gin Stephane , Michau Nicolas , Linard Yannick , Dillmann Philippe
Published: July 2020

The effect of a cement–bentonite grout material was studied through glass/steel interactions. Hence, two experimental mock‐ups, consisting of a “sandwich” of four materials in contact, stainless steel/AVM glass/AVM glass/P285NH steel, were leached by Callovo–Oxfordian poral water at 70°C for 1 year. CBG material was added for one experiment, whereas the second one was CBG‐free. Chemical and structural analyses (scanning electron microscopy–energy‐dispersive X‐ray spectroscopy, Raman), performed mainly at the AVM glass/P285NH interface, evidenced a comparable alteration with and without the CBG. Indeed, its presence did not impact the gel formation by hydrolysis/condensation mechanism. For both experiments, the glass alteration rates corresponded to , highlighting a kinetic rate drop after a 1‐year leaching period. However, the CBG impacted the pH solution initially buffered by the claystone, promoting precipitation of Mg/Fe‐rich silicates on the gel surface. Regarding P285NH corrosion, no major difference was observed with the CBG. Steel corrosion layers in both experiments were Si‐free, and the corrosion rates were similar. Therefore, after 1 year at 70°C, the CBG had a limited effect on the glass/carbon steel interactions.
Identification of the novel COL5A1 c.3369_3431dup, p.(Glu1124_Gly1144dup) variant in a patient with incomplete classical Ehlers–Danlos syndrome: The importance of phenotype‐guided genetic testing
Authors: Ritelli Marco , Cinquina Valeria , Venturini Marina , Colombi Marina
Published: July 2020

Background

Classical Ehlers–Danlos syndrome (cEDS) is a connective tissue disorder mainly caused by heterozygous COL5A1 or COL5A2 variants encoding type V collagen and rarely by the p.(Arg312Cys) missense substitution in COL1A1 encoding type I collagen. The current EDS nosology specifies that minimal suggestive criteria are marked skin hyperextensibility plus atrophic scarring together with either generalized joint hypermobility or at least three minor criteria comprising additional cutaneous and articular signs. To reach a final diagnosis, molecular testing is required. Herein, we report on a 3‐year‐old female who came to our attention with an inconclusive next generation sequencing (NGS) panel comprising all cEDS‐associated genes.

Methods

Despite the patient did not formally fulfill the nosological criteria because the skin was only slightly hyperextensible, we made a cEDS diagnosis, mainly for the presence of typical atrophic scars. We investigated COL5A1 intragenic deletions/duplications by Multiplex Ligation‐dependent Probe Amplification (MLPA), excluded the recessive classical‐like EDS type 2 by AEBP1 Sanger analysis, and retested COL5A1 with the Sanger method.

Results

Molecular analyses revealed the novel COL5A1 c.3369_3431dup p.(Glu1124_Gly1144dup) intermediate‐sized duplication with a predicted dominant negative effect that was missed both by NGS and MLPA.

Conclusions

This report highlights that some cEDS patients might not display overt skin hyperextensibility and the importance of clinical expertise to make such a diagnosis in patients with an incomplete presentation. Our results also exemplify that NGS is not a fool‐proof technology and that Sanger sequencing achieves the diagnostic goal when there is a sufficiently clear phenotypic indication.
A fractional‐order model for chronic lymphocytic leukemia and immune system interactions
Authors: Fadaei Yasin , Ahmadi Ali , Fekri Kiavash , Masoumi Rohollah , Radunskaya Ami
Published: July 2020

In this study, a mathematical, fractional‐order model was developed for B cell chronic lymphocytic leukemia, with immune system, and then analyzed. Interactions between B leukemia cells, natural killer cells, cytotoxic T cells, and T‐helper cells are considered to be incorporated into a system consisting of four fractional differential equations. For estimation of the parameters, clinical data of six patients were used. By numerical solution of the system, the interactions between the leukemia cell population and the immune system cell populations for values of α ∈ (0,1) at different times were explained. By determining points of equilibrium and stability of the system were met. Bifurcation analysis showed that use of the fractional‐order model, figure out unpredictable behaviors of the system such as saddle‐node, bistability and hysteresis phenomenon occurred in the system by changing the values of some of the parameters, it was predictable.
Determination of optimal parameters for 3D single‐point macromolecular proton fraction mapping at 7T in healthy and demyelinated mouse brain
Authors: Soustelle Lucas , Antal Maria Cristina , Lamy Julien , Harsan Laura‐Adela , Loureiro de Sousa Paulo
Published: July 2020

Purpose

To determine optimal constrained tissue parameters and off‐resonance sequence parameters for single‐point macromolecular proton fraction (SP‐MPF) mapping based on a comprehensive quantitative magnetization transfer (qMT) protocol in healthy and demyelinated living mice at 7T.

Methods

Using 3D spoiled gradient echo‐based sequences, a comprehensive qMT protocol is performed by sampling the Z‐spectrum of mice brains, in vivo. Provided additional T1, and B0 maps allow for the estimation of qMT tissue parameters, among which three will be constrained, namely the longitudinal and transverse relaxation characteristics of the free pool (R1,fT2,f), the cross‐relaxation rate (R) and the bound pool transverse relaxation time (T2,r). Different sets of constrained parameters are investigated to reduce the bias between the SP‐MPF and its reference based on the comprehensive protocol.

Results

Based on a whole‐brain histogram analysis about the constrained parameters, the optimal experimental parameters that minimize the global bias between reference and SP‐MPF maps consist of a 600° and 6 kHz off‐resonance irradiation pulse. Following a Bland‐Altman analysis over regions of interest, optimal constrained parameters were R1,fT2,f = 0.0129, R = 26.5 s−1, and T2,r = 9.1 µs, yielding an overall MPF bias of 10−4 (limits of agreement [−0.0068;0.0070]) and a relative variation of 0.64% ± 5.95% between the reference and the optimal single‐point method across all mice.

Conclusion

The necessity of estimating animal model‐ and field‐dependent constrained parameters was demonstrated. The single‐point MPF method can be reliably applied at 7T, as part of routine preclinical in vivo imaging protocol in mice.
Probing the ballistic microcirculation in placenta using flow‐compensated and non‐compensated intravoxel incoherent motion imaging
Authors: Jiang Ling , Sun Taotao , Liao Yuhao , Sun Yi , Qian Zhaoxia , Zhang Yi , Wu Dan
Published: July 2020

Purpose

Intravoxel incoherent motion (IVIM) imaging is widely used to evaluate microcirculatory flow, which consists of diffusive and ballistic flow components. We proposed a joint use of flow‐compensated (FC) and non‐compensated (NC) diffusion gradients to probe the fraction and velocity of ballistic flow in the placenta.

Methods

Forty pregnant women were included in this study and scanned on a 1.5T clinical scanner. FC and NC diffusion MRI (dMRI) sequences were achieved using a pair of identical or mirrored bipolar gradients. A joint FC‐NC model was established to estimate the fraction (fb) and velocity (vb) of the ballistic flow. Conventional IVIM parameters (f, D, and D*) were obtained from the FC and NC data, separately. The vb and f·D*, as placental flow velocity measurements, were correlated with the umbilical‐artery Doppler ultrasound indices and gestational ages.

Results

The ballistic flow component can be observed from the difference between the FC and NC dMRI signal decay curves. vb fitted from the FC‐NC model showed strong correlations with umbilical‐artery impedance indices, the systolic‐to‐diastolic (SD) ratio and pulsatility index (PI), with correlation coefficients of 0.65 and 0.62. The f·D* estimated from the NC data positively correlated with SD and PI, while the FC‐based f·D* values showed weak negative correlations. Significant gestational‐age dependence was also found in the flow velocity measurements.

Conclusion

Our results demonstrated the feasibility of using FC and NC dMRI to noninvasively measure ballistic flow velocity in the placenta, which may be used as a new marker to evaluate placenta microcirculation.
Sensitivity to myelin using model‐free analysis of the water resonance line‐shape in postmortem mouse brain
Authors: Foxley Sean , Wildenberg Gregg , Sampathkumar Vandana , Karczmar Gregory S , Brugarolas Pedro , Kasthuri Narayanan
Published: July 2020

Purpose

Dysmyelinating diseases are characterized by abnormal myelin formation and function. Such microstructural abnormalities in myelin have been demonstrated to produce measurable effects on the MR signal. This work examines these effects on measurements of voxel‐wise, high‐resolution water spectra acquired using a 3D echo‐planar spectroscopic imaging (EPSI) pulse sequence from both postmortem fixed control mouse brains and a dysmyelination mouse brain model.

Methods

Perfusion fixed, resected control (n = 5) and shiverer (n = 4) mouse brains were imaged using 3D‐EPSI with 100 µm isotropic resolution. The free induction decay (FID) was sampled every 2.74 ms over 192 echoes, for a total sampling duration of 526.08 ms. Voxel‐wise FIDs were Fourier transformed to produce water spectra with 1.9 Hz resolution. Spectral asymmetry was computed and compared between the two tissue types.

Results

The water resonance is more asymmetrically broadened in the white matter of control mouse brain compared with dysmyelinated white matter. In control brain, this is modulated by and consistent with previously reported orientationally dependent effects of white matter relative to B0. Similar sensitivity to orientation is observed in dysmyelinated white matter as well; however, the magnitude of the resonance asymmetry is much lower across all directions.

Conclusion

Results demonstrate that components of the spectra are specifically differentially affected by myelin concentration. This suggests that water proton spectra may be sensitive to the presence of myelin, and as such, could serve as a MRI‐based biomarker of dysmyelinating disease, free of mathematical models.
Bioactive ROS‐scavenging nanozymes for regenerative medicine: Reestablishing the antioxidant firewall
Authors: Wu Haibin , Liao Hongwei , Li Fangyuan , Lee Jiyoung , Hu Pingjing , Shao Wei , Li Xiangzi , Ling Daishun
Published: July 2020

Bio‐therapeutics, such as stem cells, nucleic acids, and growth factors, represent the frontier of regenerative medicines. The excessive accumulation of reactive oxygen species (ROS) is an essential mechanism in tissue degeneration or injury, which stimulates deleterious oxidative damage to the administered bio‐therapeutics. Likewise, a high level of ROS provokes critical damage to vital endogenous biomacromolecules, such as proteins, lipids, and nucleic acids, which restricts the innate regeneration. Recently, ROS‐scavenging nanozymes gain increasing attention from the field of regenerative medicine, which are able to protect bio‐therapeutics and endogenous actives from oxidative damage and facilitate innate regeneration. ROS‐scavenging nanozyme becomes a novel bioactive platform technology that enables the development of tailored materials for regenerative therapies. Herein, we provide a review on the chemical mechanism of ROS‐scavenging nanozymes, and summarize their applications within the scope of tissue repair and regeneration. We also discuss the current limitations and future directions of ROS‐scavenging nanozymes in the field of regenerative medicine from a perspective of clinical translation. Hopefully, our work may inspire further innovation of advanced ROS‐modulating biomaterials, which will accelerate the evolution of regenerative medicine.
Function of a PETN‐Based Exploding Bridgewire Detonator Post Melt
Authors: Manner Virginia W. , Yeager John D. , Smilowitz Laura , Remelius Dennis , Henson Bryan F.
Published: July 2020

Exploding bridgewire (EBW) detonators are used for a variety of purposes and subjected to a wide range of conditions during transport and use, however, few studies have been conducted on stability at high temperatures. Many EBW's contain pentaerythritol tetranitrate (PETN) as the initiating explosive, which has been shown to exhibit a relatively low melt at 141 °C, followed by an onset of decomposition of approximately 160 °C. In the present work, we have evaluated the behavior of PETN with X‐ray radiography in commercial RP‐80 EBW detonators at temperatures just above the melt. These experiments show that PETN remains stable in the solid‐state, but after reaching the melt temperature is vulnerable to mixing, followed by rapid evolution of gases and decomposition. Our results indicate that the orientation of the thermally treated detonator with respect to gravity is important after the PETN reaches the melted state: this shows for the first time why thermal tests on PETN‐based detonators often result in varied outcomes.
Electrodeposited ZnO Nanorods as Efficient Photoanodes for the Degradation of Rhodamine B
Authors: Ait hssi Abderrahim , Amaterz Elhassan , labchir Nabil , Atourki Lahoucine , Bouderbala Ibrahim Yaacoub , Elfanaoui Abdeslam , Benlhachemi Abdeljalil , Ihlal Ahmed , Bouabid Khalid
Published: July 2020

Herein the synthesis of ZnO nanorods (NRs) by means of the one‐ and two‐step electrochemical deposition (ECD) process is focused upon. A comparison of the crystal structure, morphology, optical properties, and photoelectrocatalytic (PEC) activities of nanostructured ZnO cultivated by the two methods is conducted. X‐ray diffraction (XRD) analysis reveals that all samples annealed at 300 °C are polycrystalline and have a hexagonal (wurtzite) structure and significant improvement in the crystallinity of the sample deposited by the two‐step process. The morphological characterizations show that the NRs are well hexagonal and well oriented in the same sample. The optical spectra show a transmittance higher than 70% and direct bandgaps of 3.12 and 3.04 eV for the samples synthesized by one‐step and two‐step electrodeposition, respectively. The PEC properties of the films obtained are studied and reveal an efficient and rapid rhodamine B (RhB) azo dye degradation. In addition, the scavengers of reactive species as well as the kinetics during degradation are also studied and show that the superoxide radicals contribute significantly in degradation.
Methylene Surrogates for the Synthesis of 3,3’‐Diindolylmethanes
Authors: Sarmah Debasish , Bora Utpal
Published: July 2020

Di(1H‐indol‐3‐yl)methanes (DIMs) and their derivatives are one of the highly essential indole derivatives with a broad spectrum of biological activities. The scaffold involves two indole/substituted indole moieties connected to each other via a methenyl bridge generally at the 3,3’ positions, as well as 2,2’ and 2,3’ positions. Synthesis of such moieties with the use of easily available chemicals and process is highly desirable for its tremendous importance in the fields of organic and medicinal chemistry. Herein, we review the synthesis of 3,3’‐methylene bridged indoles with the use of some methylene surrogates under various chemical and catalytic conditions.
Novel 6‐Morpholino‐9H‐purine Derivatives: Synthesis, Pharmacological and In Silico Evaluation
Authors: Nadaf AfraQuasar A. , Dixit Shruti , Yaseen Mohammed , Mantur Shivaraj , Najare Mahesh S. , Joshi Shrinivas , Vootla Shyamkumar , Khazi Imtiyaz Ahmed M.
Published: July 2020

A series of novel N‐9 substituted 6‐morpholino‐9H‐purine derivatives (PP 1–6; PO 1–6) were designed and synthesized via a multi‐step synthetic pathway. Spectroscopic techniques confirmed their chemical structures. The synthesized compounds were screened for in vitro antimicrobial, antioxidant and anti‐inflammatory activities. PP‐3, PP‐5, PP‐6, PO‐2 and PO‐5 have exhibited good activity against all the bacterial strains with MIC 4–8 μg/mL whereas PO‐5 and PO‐6 exhibited strong inhibition of fungal strains (MIC: 2–4 μg/mL). PP‐5 has strongly inhibited C. albicans with MIC 2 μg/mL which is similar to that of Fluconazole standard. The in silico studies performed on C. albicans indicated that their mode of action is by the inhibition of dihydrofolate reductase enzyme. The anti‐inflammatory and antioxidant assays have shown that the halogen substituted derivatives have good anti‐inflammatory properties while the non halogen substituted derivatives exhibited good antioxidant profile.
HClO4‐Al2O3 as a Prominent Catalyst in the Synthesis of 3,4‐Dihydropyrimidin‐2(1H)‐ones/thiones under Environmentally Friendly Solvent Conditions
Authors: Zanin Lucas L. , Porto André L. M.
Published: July 2020

An accessible, non‐toxic, easy to handle and stock catalyst with high efficiency was developed in this study for the synthesis of 3,4‐dihydropyrimidin‐2(1H)‐ones/thiones. Al2O3 was used as a support for HClO4, resulting in a heterogeneous and reusable catalyst for the Biginelli reaction. In the absence of the catalyst, the reaction provided a yield of 19%. However, in the presence of HClO4‐Al2O3 it was possible to synthesize 16 examples of DHPMs/thiones with improved yields (80‐98%), in reaction periods of 1 to 3 hours. The catalyst also stood out for its stability against temperature and the reagents used.
Introduction of Phase Change Material into Sustainable Carbon Materials for Enhanced Shape Stability and Thermal Conductivity
Authors: Zou Zhiqiang , Wu Wei , Shen Wanting
Published: July 2020

New sustainable carbon materials were synthesized from a low‐price and eco‐friendly carrot via hydrothermal reaction and carbonization approach. Afterwards, palmitic acid (PA) was impregnated into the carrot‐derived carbon material (CCM) to prepare PA@CCM composites through vacuum impregnation method. The thermal properties and shape stability of PA@CCM composites were evaluated by differential scanning calorimetry (DSC), thermal conductivity and thermal cycling tests. Owing to the special hybrid microstructure of the CCMs, the loading ratio of PA in PA@CCM composites could reach up to 85.3 % with the latent heat of 166.4 J g−1. More importantly, the PA@CCM composites show negligible leakage above the melting point of PA, exhibiting excellent shape stability. Compared with pristine PA, the thermal conductivity of PA@CCM composites could greatly enhanced by 145.5 %. Thus, PA@CCM composites can be considered as a promising candidate for thermal energy storage applications.
Synthesis and Reactivity of Heterotrinuclear Platinum Cyclometalated Complexes Containing Bridging Nitrido Ligands
Authors: Qin Shiwei , Chong Man‐Chun , Cheung Wai‐Man , H.‐Y. Sung Herman , Williams Ian D. , Leung Wa‐Hung
Published: July 2020

The treatment of [M(LOEt)(N)Cl2] (LOEt−=[Co(η5‐C5H5){P(O)(OEt)2}3]−) with the Pt(II) bis(cyclometalated) complex [Pt(C N CBu)(DMSO)] (H2C N CBu=2,6‐di(4‐tert‐butylphenyl)pyridine; DMSO=dimethylsulfoxide) afforded the heterotrinuclear nitrido complexes [LOEtCl2M(μ‐N)Pt(C N CBu)] (M=Ru (1‐Ru), Os (1‐Os)). The Pt−N(nitrido) (1.821(5) Å) and Ru−N (1.673(5) Å) distances in 1‐Ru are consistent with the Ru=N=Pt bonding description. The Pt−N(nitrido) distance in 1‐Os (1.859(7) Å) is longer than that in 1‐Ru, suggesting the π interaction between Pt(II) and Os≡N is weaker than that for the Ru counterpart. Oxidation of 1‐Ru with PhICl2 afforded the Pt(IV) dichloride complex [LOEtCl2Ru(μ‐N)Pt(C N CBu)Cl2] (2) that has a longer Pt−N distance (1.893(3) Å) than that in 1‐Ru, indicating the weakening of the Pt−N(Ru) π bonding upon oxidation of Pt(II) to Pt(IV). Treatment of [Pt(C N CBu)(DMSO)] with [nBu4N][Ru(N)Cl4] in tetrahydrofuran (THF) afforded [nBu4N][(THF)Cl4Ru(μ‐N)Pt(C N CBu)] (3), which reacted with K[N(Ph2PS)2] and K[N(iPr2PO)2] to yield [Cl{N(Ph2PS)2}2Ru(μ‐N)Pt(C N CBu)] (4) and [nBu4N][Cl3{N(iPr2PO)2}Ru(μ‐N)Pt(C N CBu)] (5), respectively. The short Pt−N(nitrido) distances in 3 (1.816(5) Å) and 4 (1.809(2) Å) are indicative of Pt=N double bond character.
How authentic leadership impacts on job insecurity: The multiple mediating role of psychological empowerment and psychological capital
Authors: Wang Dawei , Kan Wenjing , Qin Shaotian , Zhao Chaoyue , Sun Yuchen , Mao Wenxu , Bian Xiaohua , Ou Yaping , Zhao Ziyu , Hu Yixin
Published: July 2020

Previous studies have suggested that leadership style may have an impact on job insecurity among employees. Authentic leaders encourage the development of the people around them by practicing real values, beliefs and behaviours, being subordinate oriented and making honest evaluations of the behaviour and performance of employees. Authentic leadership, often considered the ‘root construct’ of other positive leadership forms, conforms to Chinese culture and hence, may be the most suitable leadership style for organizations following this culture. As the effect of authentic leadership on job insecurity is unclear, this study aimed to examine the mechanism between job insecurity and authentic leadership and further explore the mediating effect of psychological empowerment and psychological capital. The results of this study, involving 451 employees from 68 departments of a communications enterprise in China, revealed that authentic leadership has a cross‐level negative impact on employees' job insecurity. Moreover, psychological empowerment and psychological capital played a multiple mediating role between authentic leadership and job insecurity.
Oriented Perovskite Crystal towards Efficient Charge Transport in FASnI3 Perovskite Solar Cells
Authors: Gu Wenwen , Xu Xin , Chen Junwen , Ma Ben , Qin Minchao , Zhu Wenjing , Qian Jie , Qin Zhaotong , Shen Wei , Lu Yao , Zhang Wenzhu , Chen Shufen , Lu Xinhui , Huang Wei
Published: July 2020

Despite a higher power conversion efficiency (PCE) than other lead‐free perovskite solar cells (PSCs) due to intrinsically excellent optoelectronic properties and suitable bandgaps of tin (Sn) perovskites, Sn‐based PSCs still suffer from issues of stability and efficiency for practical applications. Herein, a novel strategy of tuning perovskite crystal orientation toward ≈45° with respect to the substrate by doping 2,3‐diaminopropionic acid monohydrochloride (2,3‐DAPAC) into formamidinium tin iodide (FASnI3) is proposed, which facilitates charge transport in the perovskite film and consequent device performances. In addition, the incorporation of 2,3‐DAPAC into FASnI3 enables dense and smooth high‐quality perovskite films with less Sn vacancies. Applications of the 2,3‐DAPAC‐treated FASnI3 films into PSCs acquire a champion PCE of 7.23%, showing 37.2% enhancement compared with 5.27% of the control device. Moreover, the storage stabilities of both perovskite films and PSCs are significantly prolonged with improved film quality.
Surface Passivation of All‐Inorganic CsPbI2Br with a Fluorinated Organic Ammonium Salt for Perovskite Solar Cells with Efficiencies over 16%
Authors: Chen Shan-Ci , Wang Di , Zheng Qingdong
Published: July 2020

Surface modification is demonstrated as an efficient strategy to enhance the efficiency and stability of perovskite solar cells (PVSCs). Fluorinated organic ammonium salts featuring a strong hydrophobic nature are seldom used as passivation agents for the surface modification of CsPbI2Br perovskites. Herein, a fluorinated organic ammonium halide salt, 4‐trifluoromethyl phenethylammonium iodide (CFPEAI), is incorporated into the surface of CsPbI2Br perovskite for the first time. After the CFPEAI modification, the defects of CsPbI2Br perovskite are significantly passivated with reduced trap densities. The best‐performance PVSC with CFPEAI modification shows an excellent power conversion efficiency (PCE) of 16.07% with a high fill factor (FF) of 84.65%, a short‐circuit current density (JSC) of 15.45 mA cm−2, and an open‐circuit voltage (VOC) of 1.23 V. In contrast, the control PVSCs without the surface modification exhibit a lower PCE of 14.50% with a FF of 80.56%, a JSC of 15.05 mA cm−2, and a VOC of 1.20 V. With CFPEAI passivation, the CsPbI2Br perovskite film exhibits enhanced hydrophobicity, thereby leading to improved stability for the corresponding PVSC in comparison with the control PVSC without any surface modification.
Behavior of Forging Steels under Cyclic Loading—the Benefit of Air‐Hardening Martensites
Authors: Schmiedl Tobias , Gramlich Alexander R. M. , Schönborn Steffen , Melz Tobias
Published: July 2020

The development of air‐hardening martensitic forging (LHD: luft härtend duktil) steels offers high material performance with a short and simple process route. In this study, five alloys (L1–L5), based on the existing LHD alloy concept but with different contents of aluminum, titanium, boron, and molybdenum, are cast at laboratory scale. The casted blocks are hot forged into semifinished products and cooled in air (uncontrolled). The tensile properties, the Charpy V‐notch impact energy, the cyclic material behavior, and the fatigue strength of the alloys L1–L5 are opposed to each other. Furthermore, the material properties are compared with the standard quench and tempered (Q+T) steel 42CrMo4 (reference material) and ranked against previously developed forging steels. The tensile properties and Charpy V‐notch impact energy are comparable with those of the reference material, whereas the new alloy concepts show a significantly higher cyclic yield strength and fatigue strength.
Modelling the Societal Division of Added Value Created Through Manufacturing 4.0
Authors: Hiilamo Heikki , Aaltonen Henri
Published: July 2020

While Manufacturing 4.0 will create benefits and wealth for the leading manufacturing companies that are employing automated and robotized manufacturing systems the replacement of human workers with automation and the geographical shift of manufacturing will potentially create temporary waves of risen unemployment in the manufacturing sector. This chapter discusses models for of societal systems that support the members of the society in the changing environment brought about by technology-driven disruptions, while they ensure the normal functioning of the society—views of nine experts from Germany, The Netherlands, and South Korea on these issues were elicited and are presented and shortly analyzed.
Additive Manufacturing—Past, Present, and the Future
Authors: Korpela Markus , Riikonen Niko , Piili Heidi , Salminen Antti , Nyrhilä Olli
Published: July 2020

This chapter provides a rough overall view of the current state of additive manufacturing, how the status quo was reached and what the future looks like, and how these issues are related to the Manufacturing 4.0 context. Chapter focuses on the most developed and studied form of additive manufacturing—laser based powder bed fusion of metal materials. Main challenges, possibilities, and technology readiness-level are presented together with a discussion about the approximate costs related to manufacturing with the-state-of-the-art systems.
Additive Manufacturing from the Point of View of Materials Research
Authors: Laitinen Ville , Merabtene Mahdi , Stevens Erica , Chmielus Markus , Van Humbeeck Jan , Ullakko Kari
Published: July 2020

Concentrated on additive manufacturing, this chapter discusses materials research in the Manufacturing 4.0 context. In addition to providing a brief review on stimuli-responsive materials and their applications under Manufacturing 4.0, this chapter also looks ahead and discusses in detail the recent developments in additive manufacturing of machines, particularly machines based on the special characteristics of certain stimuli-responsive materials, such as thermally activated shape memory alloys, magnetic shape memory alloys and magnetocaloric materials. Furthermore, this chapter emphasizes possible future directions for the additive manufacturing of metallic materials in general.
Non-supersymmetric branes
Authors: Cribiori Niccolò , Roupec Christoph , Tournoy Magnus , Van Proeyen Antoine , Wrase Timm
Published: July 2020

Abstract

We discuss how to incorporate non-supersymmetric branes in compactifications of type II string theories. We particularly focus on flux compactifications on SU(3) × SU(3) structure manifolds to four dimensions, so that a linear $$ \mathcal{N} $$
N
= 1 supersymmetry is spontaneously broken by spacetime filling Dp-branes. Anti-Dp-branes are a very special subset of such branes but our analysis is generic. We show that the backreaction of non-supersymmetric branes can be incorporated into the standard 4d $$ \mathcal{N} $$
N
= 1 supergravity by including a nilpotent chiral multiplet. Supersymmetry in such setups is always spontaneously broken and non-linearly realized. In particular this means that, contrary to what was previously thought, brane supersymmetry breaking cannot be simply described by a D-term in 4d $$ \mathcal{N} $$
N
= 1 supergravity theories.
Generating series of all modular graph forms from iterated Eisenstein integrals
Authors: Gerken Jan E. , Kleinschmidt Axel , Schlotterer Oliver
Published: July 2020

Abstract

We study generating series of torus integrals that contain all so-called modular graph forms relevant for massless one-loop closed-string amplitudes. By analysing the differential equation of the generating series we construct a solution for their low-energy expansion to all orders in the inverse string tensionα′. Our solution is expressed through initial data involving multiple zeta values and certain real-analytic functions of the modular parameter of the torus. These functions are built from real and imaginary parts of holomorphic iterated Eisenstein integrals and should be closely related to Brown’s recent construction of real-analytic modular forms. We study the properties of our real-analytic objects in detail and give explicit examples to a fixed order in theα′-expansion. In particular, our solution allows for a counting of linearly independent modular graph forms at a given weight, confirming previous partial results and giving predictions for higher, hitherto unexplored weights. It also sheds new light on the topic of uniform transcendentality of theα′-expansion.
A measurable angular distribution for $$ \overline{B}\to {D}^{\ast }{\tau}^{-}{\overline{v}}_{\tau } $$ decays
Authors: Bhattacharya Bhubanjyoti , Datta Alakabha , Kamali Saeed , London David
Published: July 2020

Abstract

At present, the measurements of $$ {R}_{D^{\left(\ast \right)}} $$

R

D

∗

and RJ/ψ hint at new physics (NP) in $$ b\to c{\tau}^{-}\overline{v} $$
b
→
c

τ
−

v
¯

decays. The angular distribution of $$ \overline{B}\to {D}^{\ast}\left(\to D\pi \right){\tau}^{-}{\overline{v}}_{\tau } $$

B
¯

→

D
∗

→
Dπ

τ
−

v
¯

τ

would be useful for getting information about the NP, but it cannot be measured. The reason is that the three-momentum $$ {\overrightarrow{p}}_{\tau } $$

p
→

τ

cannot be determined precisely since the decay products of the τ− include an undetected ντ. In this paper, we construct a measurable angular distribution by considering the additional decay τ−→ π−ντ. The full process is $$ \overline{B}\to {D}^{\ast}\left(\to D{\pi}^{\prime}\right){\tau}^{-}\left(\to {\pi}^{-}{v}_{\tau}\right){\overline{v}}_{\tau } $$

B
¯

→

D
∗

→
D

π
′

τ
−

→

π
−

v
τ

v
¯

τ

, which includes three final-state particles whose three-momenta can be measured: D, π′, π−. The magnitudes and relative phases of all the NP parameters can be extracted from a fit to this angular distribution. One can measure CP-violating angular asymmetries. If one integrates over some of the five kinematic parameters parametrizing the angular distribution, one obtains (i) familiar observables such as the q2 distribution and the D∗ polarization, and (ii) new observables associated with the π− emitted in the τ decay: the forward-backward asymmetry of the π− and the CP-violating triple-product asymmetry.
Improved MSSM Higgs mass calculation using the 3-loop FlexibleEFTHiggs approach including xt-resummation
Authors: Kwasnitza Thomas , Stöckinger Dominik , Voigt Alexander
Published: July 2020

Abstract

We present an improved calculation of the light CP-even Higgs boson pole mass in the MSSM based on the FlexibleEFTHiggs hybrid method. The calculation resums large logarithms to all orders and includes power-suppressed terms at fixed order. It uses state-of-the-art 2- and 3-loop matching of the quartic Higgs coupling and renormalization group running up to 4-loop, resulting in a resummation of large logarithmic corrections up to N3LL level. A conceptually novel ingredient is the expansion of the matching conditions in terms of high-scale MSSM parameters instead of SM parameters. In this way leading QCD-enhanced terms in the stop-mixing parameter are effectively resummed, leading to an improved numerical convergence of the perturbative expansion. Furthermore, the avoidance of double counting of loop corrections is more transparent than in other approaches and more independent of the high-scale model. We present numerical results and a detailed discussion of theoretical uncertainties for standard benchmark scenarios.
$$ \mathcal{SW}\left(\frac{3}{2},2\right) $$ subsymmetry in G2, Spin(7) and $$ \mathcal{N} $$ = 2 CFTs
Authors: Fiset Marc-Antoine
Published: July 2020

Abstract

Spectral flow, spacetime supersymmetry, topological twists, chiral primaries related to marginal deformations, mirror symmetry: these are important consequences of the worldsheet$$ \mathcal{N} $$N= 2 superconformal symmetry of strings on Calabi-Yau manifolds. To various degrees of certainty, these features were also established when the target is either 7d or 8d with exceptional holonomyG2or Spin(7) respectively. We show that these are more than mere analogies. We exhibit an underlying symmetry$$ \mathcal{SW}\left(\frac{3}{2},2\right) $$SW322making a bridge between the latter cases and K3 target spaces. Reviewing unitary representations of$$ \mathcal{SW}\left(\frac{3}{2},2\right) $$SW322leads us to speculate on further roles of this algebra in string theory compactifications and on the existence of topologically twisted versions of$$ \mathcal{SW}\left(\frac{3}{2},2\right) $$SW322theories.
Trifectas for TN in 5d
Authors: Eckhard Julius , Schäfer-Nameki Sakura , Wang Yi-Nan
Published: July 2020

Abstract

The trinions TN are a class of 5d $$ \mathcal{N} $$
N
= 1 superconformal field theories (SCFTs) realized as M-theory on ℂ3/ℤN× ℤN . We apply to TN , as well as closely-related SCFTs that are obtained by mass deformations, a multitude of recently developed approaches to studying 5d SCFTs and their IR gauge theory descriptions. Thereby we provide a complete picture of the theories both on the Coulomb branch and Higgs branch, from various geometric points of view — toric and gluing of compact surfaces as well as combined fiber diagrams — to magnetic quivers and Hasse diagrams.