bluuebunny/crossref_metadata_2025 huggingface dataset:
Processing of the Multifunctional Polymer Poly(phenylene methylene) into Fibers, Films, Foams, and Microspheres
Authors: Braendle Andreas , Ofner Alessandro , Perevedentsev Aleksandr , Schwendimann Pascal , Niederberger Markus , Caseri Walter R.
Published: April 2019

Poly(phenylene methylene) (PPM) has recently emerged as a promising multifunctional polymer, requiring straightforward one‐step synthesis to achieve high molar mass and featuring a range of attractive properties. Its processability, however, has not been explored in detail to date. Therefore, this study presents a comprehensive investigation of the processability of PPM into a wide range of forms by employing various polymer processing techniques. Thin fibers (diameter ≈100 µm) over 1 km in length and shorter thick fibers (diameter ≈1 mm) are produced by melt spinning. Although no crystallinity is observed, the fibers surprisingly exhibit pronounced birefringence. The capability for waveguiding red light within the fibers is also demonstrated. Furthermore, films with a broad thickness range, spanning nanometer to millimeter length scales, are fabricated using different approaches such as spin‐coating, hot pressing, and die casting. All films feature a very smooth and crack‐free surface topography. Additionally, freestanding foams of PPM are obtained by foaming highly concentrated solutions, and quasi‐monodisperse microspheres are prepared by a microfluidic high‐throughput emulsification. The material properties of these different specimen forms are investigated and discussed for implementation as products ranging from plastic optical fibers and light emitting diodes, to protective coatings and packaging, as well as insulators and separation membranes.
Polyamide/PEG Blends as Biocompatible Biomaterials for the Convenient Regulation of Cell Adhesion and Growth
Authors: Winnacker Malte , Beringer Andreas J. G. , Gronauer Thomas F. , Güngör Hicran H. , Reinschlüssel Leonhard , Rieger Bernhard , Sieber Stephan A.
Published: April 2019

In addition to their established usage in textiles, commodities, and automotives, classical polyamides (nylons) are recently becoming increasingly interesting for applications in (bio)medicine. This fact relies on many prosperous properties of these polymers, which are toughness, resistance, biocompatibility, low immunogenicity, tunable biodegradability, and their similarity to natural peptides (amide bonds). Some nylon‐based medical products do already exist for wound treatment applications, implants, and biomolecule‐interacting membranes, but the systematic use of these polymers for tissue engineering is—although desired—still to be accomplished. Inspired by this, the suitability of nylon 6 and of a related biobased and more hydrophobic terpene‐derived polyamide as surfaces for the controlled interaction with HaCat cells (human keratinocytes) are investigated herein with regard to possible applications for regenerative skin replacement. The nylons are applied as neat polymers and as hydrophilized blends/composites with polyethylene glycol and confirm their excellent suitability as biomaterials.
PARP14 promotes the proliferation and gemcitabine chemoresistance of pancreatic cancer cells through activation of NF‐κB pathway
Authors: Yao Na , Chen Qiuyang , Shi Weihai , Tang Liming , Fu Yue
Published: April 2019

Pancreatic cancer (PC) is the most fatal gastrointestinal malignancy in the world, with a 5‐year relative survival of only 8%. Poly(ADP‐ribose) polymerase (PARP)14, a member of the macro‐PARP subfamily proteins, has been reported to participate in various biologic and pathologic processes in multiple cancers. The roles and underlying molecular mechanisms of PARP14 in PC carcinogenesis, however, remain to be elucidated. In this study, we for the first time discovered that PARP14 was highly expressed in human primary PC specimens and significantly correlated with poor patient prognosis. Using loss‐of‐function studies in vitro and in vivo, we showed that the knockdown of PARP14 led to enhanced apoptosis, repressed proliferation, and gemcitabine (GEM) resistance of PC cells. Further investigations revealed that PARP14 was significantly overexpressed in GEM‐resistant PC cells (SW1990/GZ). And silencing of PARP14 significantly reversed the GEM resistance of SW1990/GZ cells. To the mechanism, PARP14 could stimulate PC progression by the activation of nuclear factor‐κB (NF‐κB) signaling pathway. And inhibition of NF‐κB signal could significantly reverse PARP14–overexpression triggered PC carcinogenesis. In conclusion, PARP14 could promote PC cell proliferation, antiapoptosis, and GEM resistance via NF‐κB signaling pathway, highlighting its potential role as a therapeutic target for PC.
Comparison of gene mutation spectrum of thalassemia in different regions of China and Southeast Asia
Authors: Yang Zhuo , Cui Quexuan , Zhou Wenzhe , Qiu Ling , Han Bing
Published: April 2019

Background

Thalassemia is a common genetic disorder. High prevalence of thalassemia is found in South China, Southeast Asia, India, the Middle East, and the Mediterranean regions. Thalassemia was thought to exist only in southern China, but an increasing number of cases from northern China have been recently reported.

Methods

During 2012 to 2017, suspected thalassemia people were detected for common α‐ and β‐thalassemia mutations by gap‐Polymerase Chain Reaction (PCR) and reverse dot blot (RDB) analysis in Peking Union Medical College Hospital. One thousand and fifty‐nine people with thalassemia mutations were analyzed retrospectively. We picked mutated individuals who originally came from northern areas, and conducted telephone follow‐up survey in order to collect their ancestral information. Besides, we used “thalassemia”, “mutation”, and “Southeast Asian countries” as keywords to search the relevant studies in PubMed and Embase databases.

Results

All carriers included in our study were resided in northern China. Among them, 17.3% were native northerners and 82.7% were immigrants from southern China. Although substantial difference was found in α‐ and β‐thalassemia ratio and detailed spectrum of α‐ and β‐globin mutation spectrum between our data and data obtained from a previous meta‐analysis literature focused on southern China, the most common gene mutations were the same. Similar β‐thalassemia mutation spectrum was found among Thai, Malaysian Chinese, and Guangdong people, however, no other similarities in gene profile were found between Chinese and other ethnic groups in Southeast Asia.

Conclusion

Chinese people in different areas had similar gene mutation, whereas they had significantly different mutation spectrums from other ethnic groups in Southeast Asia.
Clinical utility in infants with suspected monogenic conditions through next‐generation sequencing
Authors: Hong Sha , Wang Li , Zhao Dongying , Zhang Yonghong , Chen Yan , Tan Jintong , Liang Lili , Zhu Tianwen
Published: April 2019

Background

Rare diseases are complex disorders with huge variability in clinical manifestations. Decreasing cost of next‐generation sequencing (NGS) tests in recent years made it affordable. We witnessed the diagnostic yield and clinical use of different NGS strategies on a myriad of monogenic disorders in a pediatric setting.

Methods

Next‐generation sequencing tests are performed for 98 unrelated Chinese patients within their first year of life, who were admitted to Xin Hua Hospital, affiliated with Shanghai Jiao Tong University School of Medicine, during a 2‐year period.

Results

Clinical indications for NGS tests included a range of medical concerns. The mean age was 4.4 ± 4.2 months of age for infants undergoing targeting specific (known) disease‐causing genes (TRS) analysis, and 4.4 ± 4.3 months of age for whole‐exome sequencing (WES) (p > 0.05). A molecular diagnosis is done in 72 infants (73.47%), which finds a relatively high yield with phenotypes of metabolism/homeostasis abnormality (HP: 0001939) (odds ratio, 1.83; 95% CI, 0.56–6.04; p = 0.32) and a significantly low yield with atypical symptoms (without a definite HPO term) (odds ratio, 0.08; 95% CI, 0.01–0.73; p = 0.03). TRS analysis provides molecular yields higher than WES (p = 0.01). Ninety‐eight different mutations are discovered in 72 patients. Twenty‐seven of them have not been reported previously. Nearly half (43.06%, 31/72) of the patients are found to carry 11 common disorders, mostly being inborn errors of metabolism (IEM) and neurogenetic disorders and all of them are observed through TRS analysis. Eight positive cases are identified through WES, and all of them are sporadic, of highly variable phenotypes and severity. There are 26 patients with negative findings in this study.

Conclusion

This study provides evidence that NGS can yield high success rates in a tertiary pediatric setting, but suggests that the scope of known Mendelian conditions may be considerably broader than currently recognized.
Maternal genetic markers for risk of celiac disease and their potential association with neural tube defects in offspring
Authors: Hoang Thanh T. , Lei Yunping , Mitchell Laura E. , Sharma Shreela V. , Swartz Michael D. , Waller D. Kim , Finnell Richard H. , Benjamin Renata H. , Browne Marilyn L. , Canfield Mark A. , Lupo Philip J. , McKenzie Paige , Shaw Gary M. , Agopian A. J. ,   The National Birth Defects Prevention Study
Published: April 2019

Background

We examined the association between the maternal genotype for celiac disease‐associated variants and risk of neural tube defects (NTDs).

Methods

We conducted a case–control study, using data from the National Birth Defects Prevention Study. We evaluated 667 cases (women with an offspring with NTD) and 743 controls (women with an offspring without a birth defect). We classified women as having low, intermediate, or high risk of celiac disease based on human leukocyte antigen (HLA) variants. We used logistic regression to assess the relationship between HLA celiac risk group (low, intermediate, high) and risk of NTDs. Fifteen non‐HLA variants (identified from genome‐wide association studies of celiac disease) were individually evaluated and modeled additively.

Results

There was no association between HLA celiac risk group and NTDs (intermediate vs. low risk: aOR, 1.0; 95% CI, 0.8–1.3; high vs. low risk: aOR, 0.8; 95% CI, 0.5–1.3). Of the fifteen non‐HLA variants, we observed five significant associations after accounting for multiple comparisons. Three negative associations were observed with rs10903122, rs13314993, rs13151961 (aOR range: 0.69–0.81), and two positive associations were observed with rs13003464 and rs11221332 (aOR range: 1.27–1.73).

Conclusion

If confirmed, our results suggest that the maternal variants related to celiac disease may be involved in the risk of NTDs.
Approximation properties of λ‐Bernstein‐Kantorovich operators with shifted knots
Authors: Rahman Shagufta , Mursaleen Mohammad , Acu Ana Maria
Published: April 2019

In the present article, Kantorovich variant of λ‐Bernstein operators with shifted knots are introduced. The advantage of using shifted knot is that one can do approximation on [0,1] as well as on its subinterval. In addition, it adds flexibility to operators for approximation. Some basic results for approximation as well as rate of convergence of the introduced operators are established. The rth order generalization of the operator is also discussed. Further for comparisons, some graphics and error estimation tables are presented using MATLAB.
Sex-Specific Dynamic Rates in the Alligator Gar: Implications for Stock Assessment and Management
Authors: Daugherty Daniel J. , Buckmeier David L. , Smith Nathan G.
Published: April 2019

Growth and mortality are commonly estimated for fish populations; however, potential differences between males and females receive less attention. Quantifying sex-specific dynamic rates can be important as they can lead to differential exploitation, altered sex ratios, and reduced reproductive potential. We examined sex-specific growth, size and age structure, maximum observed age, longevity, and total mortality using total length (TL), age, and sex collected from 549 Alligator Gar Atractosteus spatula from multiple Texas systems. Males (n = 324) ranged from 353 to 2,051 mm TL and 1–61 years of age, whereas females (n = 225) were 385 to 2,420 mm TL and 1–60 years old. We found significant differences in population-specific size and age distributions between sexes. Greater than 91% of males were less than 1,500 mm TL, whereas over 63% of females sampled were greater than this length. Sixty-four percent of males were ≤ 10 years old as compared with only 20% of females. Sex-specific estimates of longevity and total mortality indicated that females lived 10–15 years longer than males and exhibited 25% to 40% lower total mortality. Despite similar growth rates for males and females prior to age 3, female Alligator Gar growth was greater than males at older age-classes, resulting in a 617-mm difference in theoretical maximum length based on the double von Bertalanffy growth model. The considerable differences we observed between sexes have important implications for population sampling and stock assessment and highlight the importance of collecting sex-specific data.
Minimum reload cost cycle cover in complete graphs
Authors: Büyükçolak Yasemin , Gözüpek Didem , Özkan Sibel
Published: April 2019

The reload cost refers to the cost that occurs along a path on an edge‐colored graph when it traverses an internal vertex between two edges of different colors. Galbiati et al. introduced the Minimum Reload Cost Cycle Cover problem, which is to find a set of vertex‐disjoint cycles spanning all vertices with minimum reload cost. They proved that this problem is strongly NP‐hard and not approximable within 1/ϵ for any ϵ > 0 even when the number of colors is 2, the reload costs are symmetric and satisfy the triangle inequality. In this paper, we prove that the minimum reload cost is zero on complete graphs with n vertices and an equitable 2‐edge‐coloring except possibly n = 4 or with a nearly equitable 2‐edge‐coloring except possibly for n ≤ 13. Furthermore, we provide a polynomial‐time algorithm that constructs a monochromatic cycle cover in complete graphs Kn with an equitable 2‐edge‐coloring except possibly for n = 4. This algorithm also finds a monochromatic cycle cover in complete graphs with a nearly equitable 2‐edge‐coloring except for some special cases.
Prevalence of suicidal behaviour among nursing and midwifery college students in Ghana
Authors: Quarshie Emmanuel Nii‐Boye , Cheataa‐Plange Haziel Vera , Annor Francis , Asare‐Doku Winifred , Lartey Joshua King Safo
Published: April 2019

Aim

To provide exploratory and descriptive evidence on the prevalence estimate and some demographic correlates of suicidal behaviour among nursing and midwifery college students in Ghana.

Design

We used a cross‐sectional survey design.

Method

An anonymous survey involving a randomly selected sample of 305 nursing and midwifery college students was conducted in March–May 2017. The Suicide Behavior Questionnaire‐Revised was used to assess suicidal behaviour (i.e., ideation, planning, threat and attempt) and suicidal behaviour risk.

Results

The lifetime prevalence of suicide ideations (15.4%; 95% confidence interval [CI] = 0.11–0.20), plans (6.6%; 95% CI = 0.04–0.10), attempts (2.3%; 95% CI = 0.01–0.05), threats (13.4%; 95% CI = 0.10–0.18) and 12‐month prevalence of ideations (21.3%; 95% CI = 0.17–0.26) are comparable to estimates found in both high‐income and low‐ and middle‐income countries. However, associations between the demographic variables studied and suicidal behaviour risk were not statistically significant.
Failing to Fail nursing students among mentors: A confirmatory factor analysis of the Failing to Fail scale
Authors: Bachmann Liv , Groenvik Cecilie Katrine Utheim , Hauge Kari Westad , Julnes Signe
Published: April 2019

Aim

The aim was to explore the psychometric properties with respect to the internal consistency reliability of the subject‐specific questionnaire “Failing to Fail.”

Design

Cross‐sectional study.

Methods

Exploratory factor analysis with varimax rotation. A confirmatory factor analysis was used to examine the factor structure of the “Failing to Fail” scale. The sample included 336 Norwegian nurse mentors.

Results

The confirmatory factor analysis confirmed a five‐factor structure of the “Failing to Fail” scale with adequate model fit. The factors were named as: (a) Insufficient mentoring competence; (b) Insufficient support in the working environment; (c) Emotional process dominates the assessment; (d) Insufficient support from the university; and (e) Decision‐making detached from learning outcomes. The scale proved to be feasible to test whether mentors are Failing to Fail nursing students. The confirmatory factor analysis model supported the predictive validity of the “Failing to Fail” scale.
Craft a compelling evidence‐based story to draw learners to campus
Authors: Sutton Halley
Published: April 2019

ATLANTA — If a picture's worth a thousand words, then an accurate snapshot of how your institution will enrich the lives of your students is worth at least a brochure. But how can you properly convey the full scope of the return on investment students can expect when they attend your institution?
Unconventional monetary policy spillovers: Evidence from India
Authors: Thomas Aiswarya , Kumar Lakshmi
Published: April 2019

Many of the studies on the unconventional monetary policy spillover effects concentrated primarily on the policy announcements of the U.S. Federal Reserve. Using a time series approach, with dummies in the event study framework, this study estimates the monetary policy spillover effects of the unconventional monetary policy announcements of the central banks of four major economic regions: the United States, the United Kingdom, European Central bank, and Japan on the asset prices in India. In addition to that, this study estimates the asymmetry in the responses to positive and negative surprise announcements. The study reveals that unconventional monetary surprises do not have any significant impact on the asset prices in India in a narrow time window.
The mobility of PEG chains versus micellar stability towards the formation of PE‐b‐PEG nanohybrid shish‐kebab on carbon nanotubes
Authors: Le Tuan , Subramanian Ramalingam , Ajala Oluwakemi , Pellegrin Padma , Depan Dilip
Published: April 2019

A comparative study of the effect of copolymer composition on nanohybrid shish‐kebab (NHSK) architecture on carbon nanotubes (CNTs) is presented. A semi‐crystalline amphiphilic di‐block copolymer, polyethylene‐b‐polyethylene glycol (PE‐b‐PEG) was used in this study. Copolymer composition was varied on the basis of the molecular weight of individual copolymers and the ratio between PE and PEG. NHSK structure was characterized using a combination of scanning and transmission electron microscopy. The mobility of PEG, which is determined by its chain length was found to have a significant impact on the periodic decoration of the copolymer on CNTs. With higher chain length or molecular weight, PEG chains provided better stability to micelles formed by the copolymer. Further, PEG assisted micellar stability to create a foundation for PE chains to interact and orient along the tube axis of CNTs as a function of the copolymer composition. It was found that the stability of NHSK architecture can also be changed over time at the same crystallization temperature. This work offers novel and fundamental insights towards the mobility of PEG in the copolymer and its disk‐shaped crystal's formation and micellar stability during crystallization with CNTs. This study provides a better understanding of a mechanically tunable NHSK where the architecture of copolymer crystals can be modified by adjusting the molecular weight of PEG.
Photothermal/Photodynamic Therapy with Immune‐Adjuvant Liposomal Complexes for Effective Gastric Cancer Therapy
Authors: Meng Xiangbo , Wang Ke , Lv Lin , Zhao Ye , Sun Chen , Ma Lianjun , Zhang Bin
Published: April 2019

A diagnosis and therapeutic strategy for gastric cancer is developed herein by combining thermosensitive liposomal (TSL)‐based photothermal/photodynamics therapy (PTT/PDT) with chemotherapy and adjuvant immunotherapy. IR820, a photothermal agent, paclitaxel (PTX), an antitumor drug, and imiquimod (R837), a Toll‐like‐receptor‐7 agonist, are coencapsulated into a TSL drug delivery system. These formed PTX‐R837‐IR820@TSL complexes exhibit excellent optical properties, good dispersibility, and stability. Under NIR light irradiation, the measurement of singlet oxygen production and thermal efficiency indicate promising potential of PTX‐R837‐IR820@TSL complexes for PTT and PDT. Confocal microscopy and small animal NIR imaging demonstrate tumor targeting ability of the liposomal complexes to gastric cancer cells. In vitro cell viability assays and in vivo animal experiments show prominent antitumor efficiency of PTX‐R837‐IR820@TSL complexes upon NIR light irradiation. This excellent therapeutic efficacy is attributed to the simultaneous chemotherapy and PTT/PDT. Furthermore, the liposomal complexes under NIR irradiation would ablate tumors to generate a pool of tumor‐associated antigens, which is able to promote strong antitumor immune responses in the presence of those R837‐containing liposomal complexes acted as adjuvant. These results indicate that the multifunctional liposomal complexes could realize a remarkable synergistic therapeutic outcome in gastric carcinoma.
Quantum Networks with Deterministic Spin–Photon Interfaces
Authors: Borregaard Johannes , Sørensen Anders Søndberg , Lodahl Peter
Published: April 2019

This report considers how recent experimental progress on deterministic solid‐state spin–photon interfaces enables the construction of a number of key elements of quantum networks. After reviewing some of the recent experimental achievements, a discussion of their integration into Bell state analyzers, quantum non‐demolition detection, and photonic cluster state generation is presented. Finally, it is outlined how these elements can be used for long‐distance entanglement generation and quantum key distribution in a quantum network.
Practical and theoretical considerations for the determination of δ13CVPDB values of methylmercury in the environment
Authors: Dunn Philip J.H. , Bilsel Mine , Şimşek Adnan , Gören Ahmet Ceyhan , Tunç Murat , Ogrinc Nives , Horvat Milena , Goenaga‐Infante Heidi
Published: April 2019

Rationale

Analytical methods that can identify the source and fate of mercury and organomercury compounds are likely to be useful tools to investigate mercury in the environment. Carbon isotope ratio analysis of methylmercury (MeHg) together with mercury isotope ratios may offer a robust tool to study environmental cycling of organomercury compounds within fish tissues and other matrices.

Methods

MeHg carbon isotope ratios were determined by gas chromatography/combustion‐isotope ratio mass spectrometry (GC/C‐IRMS) either directly or following derivatization using sodium tetraethylborate. The effects of a normalization protocol and of derivatization on the measurement uncertainty of the methylmercury δ13CVPDB values were investigated.

Results

GC/C‐IRMS analysis resulted in a δ13CVPDB value for an in‐house MeHg reference material of δ13CVPDB = −68.3 ± 7.7‰ (combined standard uncertainty, k = 1). This agreed very well with the value obtained by offline flow‐injection analysis/chemical oxidation/isotope ratio mass spectrometry of δ13CVPDB = −68.85 ± 0.17‰ (combined standard uncertainty, k = 1) although the uncertainty was substantially larger. The minimum amount of MeHg required for analysis was determined to be 20 μg.

Conclusions

While the δ13CVPDB values of MeHg can be obtained by GC/C‐IRMS methods with or without derivatization, the low abundance of MeHg precludes such analyses in fish tissues unless there is substantial MeHg contamination. Environmental samples with sufficient MeHg pollution can be studied using these methods provided that the MeHg can be quantitatively extracted. The more general findings from this study regarding derivatization protocol implementation within an autosampler vial as well as measurement uncertainty associated with derivatization, normalization to reporting scales and integration are applicable to other GC/C‐IRMS‐based measurements.
Multidimensional environmental social governance sustainability framework: Integration, using a purchasing, operations, and supply chain management context
Authors: Whitelock Vincent G.
Published: April 2019

Academics and practitioners promote integration as the thread that holds processes together and is pursued by those who seek efficiency and effectiveness. Integration may be described as any activity, or group of activities, concerning interaction and collaboration, in which individuals, and or organizations, work together in cooperative ways, to achieve mutually acceptable outcomes. Consistent with this notion, this paper proposes a unique, innovative, comprehensive, multidimensional environmental social governance (ESG) sustainability framework to inform on the relationships among integration concepts, ESG sustainability initiatives, distinct management processes, and key supply chain members. Using stakeholder theory as the underlying referent theoretical base, this manuscript informs on the alignment and integration of sustainability reporting and financial reporting to help researchers and practitioners overcome many of the shortcomings of current sustainability frameworks, as well as enable companies, which do not yet have an established sustainability strategy, to define potential initiatives and interventions towards sustainability.
A Bayesian adaptive marker‐stratified design for molecularly targeted agents with customized hierarchical modeling
Authors: Zang Yong , Guo Beibei , Han Yan , Cao Sha , Zhang Chi
Published: April 2019

It is well known that the treatment effect of a molecularly targeted agent (MTA) may vary dramatically, depending on each patient's biomarker profile. Therefore, for a clinical trial evaluating MTA, it is more reasonable to evaluate its treatment effect within different marker subgroups rather than evaluating the average treatment effect for the overall population. The marker‐stratified design (MSD) provides a useful tool to evaluate the subgroup treatment effects of MTAs. Under the Bayesian framework, the beta‐binomial model is conventionally used under the MSD to estimate the response rate and test the hypothesis. However, this conventional model ignores the fact that the biomarker used in the MSD is, in general, predictive only for the MTA. The response rates for the standard treatment can be approximately consistent across different subgroups stratified by the biomarker. In this paper, we proposed a Bayesian hierarchical model incorporating this biomarker information into consideration. The proposed model uses a hierarchical prior to borrow strength across different subgroups of patients receiving the standard treatment and, therefore, improve the efficiency of the design. Prior informativeness is determined by solving a “customized” equation reflecting the physician's professional opinion. We developed a Bayesian adaptive design based on the proposed hierarchical model to guide the treatment allocation and test the subgroup treatment effect as well as the predictive marker effect. Simulation studies and a real trial application demonstrate that the proposed design yields desirable operating characteristics and outperforms the existing designs.
Biocompatible Tin Oxide Nanoparticles: Synthesis, Antibacterial, Anticandidal and Cytotoxic Activities
Authors: Rehman Suriya , Asiri Sarah Mousa , Khan Firdos Alam , Jermy B Rabindran , Khan Hafeezullah , Akhtar Sultan , Jindan Reem Al , Khan Khalid Mohammed , Qurashi Ahsanulhaq
Published: April 2019

Biocompatible SnO2 NPs, were synthesized by simple and facile ultrasonic technique, and further studied for antibacterial, anticandidal and invitro cytotoxic activity. The obtained size of synthesized SnO2 NPs, was 5–30 nm and characterized by X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The evaluation of antibacterial and anticandidal activity of the SnO2 NPs, was done by determining the minimum inhibitory concentration (MIC), and minimum bactericidal/fungicidal concentration (MBC/MFC), against Escherichia coli and Candida albicans, respectively. The MIC of 0.5 mg/ml and MBC of >1 mg/ml for E. coli, while as the MIC of 8 mg/ml and MFC >16 mg/ml for C. albicans, was obtained. Maximum activity for both, bacteria and Candida was achieved, however, to the best of our knowledge, this is the first report of anticandidal activity exhibited by SnO2 NPs. Treatment of synthesized SnO2 NPs against the colorectal (HCT‐116) cancer cell line, decreased the cell survivability in a dose‐dependent manner, as lower dose showed decrease of 73.00%, whereas, higher dosage caused a significant 31.34% decrease in the cell viability. The obtained results confirmed, that the prepared SnO2 NPs can be the future broad‐spectrum antibacterial, anticandidal and anticancer agent, and can be further explored for application in the biomedical field.
Computational Investigation on Series of Metal‐Free Sensitizers in Tetrahydroquinoline with Different π‐spacer Groups for DSSCs
Authors: Arunkumar A. , Deepana M. , Shanavas S. , Acevedo R. , Anbarasan P. M.
Published: April 2019

Dye‐sensitized solar cells (DSSCs) have considerable attention to the academic and industrial community. Because, it makes solar energy efficient and cost effective to harness. DSSCs is one of the important roles in the design of sensitizers with sustainable and environmentally‐friendly materials. In the present work, a series of D‐π‐A architecture with tetrahydroquinoline based organic dye sensitizer were designed and modifying π‐linker (SP1‐SP9) for the potential use in DSSCs application by DFT and TD‐DFT calculations. There are different functional groups were analyzed through a proper methodology for calculations and comparison with C1‐1 dye. From these functionals, the TD‐ωB97XD method was reasonably capable of predicting the absorption spectra of the molecules. Moreover, SP1‐SP9 dye molecules were systematically analyzed by using various parameters such as the energy gap (
), absorption spectra, light harvesting efficiency (LHE), open circuit photovoltage (
), dipole moment (
), free energy change for electron injection (
), regeneration (
) and chemical hardness (η). As a whole, all the designed dyes, especially SP6, SP7, SP8 dyes are showed smaller
, red‐shift absorption spectra, largest
, negative
and fastest
values, compared to C1‐1. Based on our result shows that SP6, SP7 and SP8 dye molecules are the best candidates to provide superior performances in the DSSCs application.
Threat of platform‐owner entry and complementor responses: Evidence from the mobile app market
Authors: Wen Wen , Zhu Feng
Published: April 2019

Research Summary

This paper studies the impact of platform‐owner entry threat on complementors in platform‐based markets. We examine how app developers on the Android mobile platform adjust innovation efforts (rate and direction) and value‐capture strategies in response to the threat of Google's entry into their markets. We find that after Google's entry threat increases, affected developers reduce innovation and raise the prices for the affected apps. However, their incentives to innovate are not completely suppressed; rather, they shift innovation to unaffected and new apps. Given that many apps already offer similar features, Google's entry threat may thus reduce wasteful development efforts. We discuss the implications of these results for platform owners, complementors, and policy makers.

Managerial Summary

We examine one prevalent source of conflict: platform owners' entry into complementary product spaces. We show that app developers on Google's Android system are strategic and nimble actors. They respond to the threat of Google's entry by adjusting both value‐creation and value‐capture strategies. We also show that platform owners could use direct entry to shape innovation directions and encourage variety of complements. Overall, on the one hand, Google's entry may have pushed complementors into other areas (which might be less lucrative) and strengthened its position in the mobile market. On the other hand, the entry may have reduced wasteful production efforts in the development of redundant applications. The overall welfare implication is thus ambiguous.
Nanowire‐Seeded Growth of Single‐Crystalline (010) β‐Ga2O3 Nanosheets with High Field‐Effect Electron Mobility and On/Off Current Ratio
Authors: Wu Zhengyuan , Jiang Zhuoxun , Song Pengyu , Tian Pengfei , Hu Laigui , Liu Ran , Fang Zhilai , Kang Junyong , Zhang Tong‐Yi
Published: April 2019

2D β‐Ga2O3 nanosheets, as fundamental materials, have great potential in next generations of ultraviolet transparent electrodes, high‐temperature gas sensors, solar‐blind photodetectors, and power devices, while their synthesis and growth with high crystalline quality and well‐controlled orientation have not been reported yet. The present study demonstrates how to grow single‐crystalline ultrathin quasi‐hexagonal β‐Ga2O3 nanosheets with nanowire seeds and proposes a hierarchy‐oriented growth mechanism. The hierarchy‐oriented growth is initiated by epitaxial growth of a single‐crystalline β‐Ga2O3 nanowire on a GaN nanocrystal and followed by homoepitaxial growth of quasi‐hexagonal (010) β‐Ga2O3 nanosheets. The undoped 2D (010) β‐Ga2O3 nanosheet field effect transistor has a field‐effect electron mobility of 38 cm2 V−1 s−1 and an on/off current ratio of 107 with an average subthreshold swing of 150 mV dec−1. The from‐nanowires‐to‐nanosheets technique paves a novel way to fabricate nanosheets, which has great impact on the field of nanomaterial synthesis and growth and the area of nanoelectronics as well.
Covalently Linked Perylene Diimide–Polydiacetylene Nanofibers Display Enhanced Stability and Photocurrent with Reversible FRET Phenomenon
Authors: Seo Joonsik , Kantha Chandra , Joung Joonyoung F. , Park Sungnam , Jelinek Raz , Kim Jong‐Man
Published: April 2019

Because of their unique structural and optical properties, 1D perylene diimide (PDI) derivatives have gained attention for use in optoelectronic devices. However, PDI‐containing self‐assembled supramolecular systems often are of limited use because they have supramolecular architectures that are held together by weak noncovalent π–π stacking, hydrogen bonding, and hydrophobic interactions. As a result, they are intrinsically unstable under solution‐processing conditions. To overcome this limitation, a polydiacetylene (PDA)‐based strategy is developed to construct a solvent‐resistant and stable PDI assembly. For this purpose, first the monomer PDI–BisDA is generated, in which two polymerizable diacetylene (DA) units are covalently linked to a PDI core. Importantly, 254 nm UV irradiation of self‐assembled PDI–BisDA nanofibers forms solvent‐resistant and stable PDI–PDA fibers. Owing to the presence of PDA, the generated polymer fibers display an increased photocurrent. In addition, the existence of PDA and PDI moieties in the fiber leads to the occurrence of switchable on–off fluorescence resonance energy transfer (FRET) between the PDI and reversibly thermochromic PDA chromophores.
Direct Synthesis of Metal‐Doped Phosphorene with Enhanced Electrocatalytic Hydrogen Evolution
Authors: Liu Danni , Wang Jiahong , Lu Jiang , Ma Chao , Huang Hao , Wang Zhongzheng , Wu Lie , Liu Qian , Jin Shaowei , Chu Paul K. , Yu Xue‐Feng
Published: April 2019

2D materials with large specific surface area and robust mechanical properties are appropriate for electrocatalysis. However, the unsatisfactory adsorption energy and limited active sites restrict their commercial application. Herein, a facile and rapid electrochemical strategy enabling synchronous exfoliation and doping is designed to directly synthesize metal‐doped 2D materials from the bulk crystals. By using black phosphorus as a model, various metal doped phosphorene such as BP(Co), BP(Mo), and BP(Ni) is obtained, and a synergistic synthesis mechanism is proposed. Notably, the dopant introduces electronic band transformation, charge redistribution, and state occupation confirmed by density functional theory calculations. Owing to the enhanced electro‐conductivity, abundant metal‐P active sites, and optimized adsorption energy by doping, the BP(metal) exhibits enhanced hydrogen evolution reaction activities and stability in comparison to the bare phosphorene. Particularly, BP(Co) presents highest activity with a potential of 0.294 V at 10 mA cm−2 (the current density is normalized with electrochemical surface area by using a double‐layer capacitance method). This study provides new access to synthesize highly efficient electrocatalysts, and also enriches the structure modulation means for layered 2D materials.
Improving Performance and Stability of Planar Perovskite Solar Cells through Grain Boundary Passivation with Block Copolymers
Authors: Wang Changlei , Song Zhaoning , Zhao Dewei , Awni Rasha A. , Li Chongwen , Shrestha Niraj , Chen Cong , Yin Xinxing , Li Dengbing , Ellingson Randy J. , Zhao Xingzhong , Li Xiaofeng , Yan Yanfa
Published: April 2019

Organic–inorganic metal halide perovskite solar cells (PSCs) exhibit excellent photovoltaic performance but have the drawbacks of instabilities against moisture and heat due to the inherent hydroscopic nature and volatility of their organic components. Herein, it is reported that using the block copolymer F127 as the passivation reagent in conjunction with the solvent annealing process can efficiently improve the performance and stability of corresponding organic–inorganic PSCs. It is anticipated that the hydrophilic poly(ethylene oxide) tails of F127 polymers connect with contiguous perovskite crystals and passivate defects at perovskite grain boundaries, whereas the dangling hydrophobic poly(phenyl oxide) centers suppress perovskite decomposition caused by moisture and heat. After the optimization of the F127 additive, planar PSCs with champion power conversion efficiencies of 21.01% and 18.71% are achieved on rigid and flexible substrates, respectively. The F127 passivation strategy provides an effective approach for fabricating high‐efficiency and stable PSCs.
Reusability of components from single‐storey steel‐framed buildings
Authors: Hradil Petr , Fülöp Ludovic , Ungureanu Viorel
Published: April 2019

This paper presents the development of the method for predicting the reusability of building components and whole structures and a pilot study of three different single‐storey steel buildings in Finland. The method enables various building parts and products to be classified through a procedure to calculate their reusability index. These values can be further used to produce a single reusability indicator for the whole end‐of‐life scenario (e.g. complete or partial building reuse). The aggregated result of the whole building may be very useful when planning demolition or reconstruction works as well as when assessing the environmental impact of the new buildings. The main new thing explored in this paper is the possibility of integrating the economyaspect of the recovered components in the reusability assessment. Indeed, the reusability index developed earlier was purely based on the technical requirements of recovering, remanufacturing and reusing components. Hence, it was a technical reusability indicator. The possibility ofincluding information on the prospective marketability of the recovered component is a valuable extension to this method.
Hierarchical third‐order tensor decomposition through inverse difference pyramid based on the three‐dimensional Walsh–Hadamard transform with applications in data mining
Authors: Kountchev Roumen K. , Iantovics Barna L. , Kountcheva Roumiana A.
Published: April 2019

A new approach is presented for hierarchical decomposition of third‐order tensors through their transformation into the generalized three‐dimensional (3D) spectrum space based on the inverse difference pyramid (IDP). For this, we choose the 3D Walsh–Hadamard transform (3D‐WHT). As result, each tensor is represented as a spectral tensor of m hierarchical levels which contains selected low‐frequency 3D‐WHT coefficients. Calculating sequentially the inverse 3D‐WHT for the coefficients from each pyramid level starting from its top, the tensor is approximated with increasing accuracy until its full restoration is achieved. To illustrate the new approach, given is the algorithm for hierarchical three‐level tensor decomposition based on the reduced IDP. The proposed approach permits simultaneous decorrelation of tensor elements in three mutually orthogonal directions. The energy of the tensor elements is concentrated in a small number of spectral coefficients which build the top of the inverse pyramid. The use of the 3D‐WHT permits to achieve minimum computational complexity, compared to deterministic 3D orthogonal transforms. The main applications of the new method for data mining in the contemporary intelligent systems are in the processing and analysis of large sets of different kinds of data/images/videos in the following areas: Compression of correlated image sequences, computer tomography, thermo vision, ultrasound and multichannel medical signals; search of 3D objects in image databases; extraction of features for recognition of 3D objects; multidimensional data denoising; multilayer watermarking of video sequences; and so on.

This article is categorized under:

Fundamental Concepts of Data and Knowledge > Big Data Mining

Algorithmic Development > Spatial and Temporal Data Mining
Syntheses, Crystal Structures, and Properties of Two Novel CL‐20‐based Cocrystals
Authors: Liu YuJia , Lv Penghao , Sun Chenghui , Pang Siping
Published: April 2019

In recent years, cocrystallization has emerged as an effective way of tuning the properties of compounds and has been widely used in the field of energetic materials. In this study, we have prepared two novel cocrystals of CL‐20 and methylimidazole, including a 1:2 CL‐20 / 2‐mercapto‐1‐methylimidazole (1) and a 1:4 CL‐20 / 4‐methyl‐5‐nitroimidazole (2). Cocrystal 1 has good physical and detonation properties (ρ1 = 1.652 g·cm–3, D1 = 7073 m·s–1, P1 = 21.6 GPa); however, cocrystal 2 shows higher properties (ρ2 = 1.680 g·cm–3, D2 = 7945 m·s–1, P2 = 27.4 GPa). The performance of both cocrystals is better than those of TNT. Thermal performance suggests that both the cocrystals have moderate thermal stabilities. Cocrystal 1 decomposes at 164.9 °C and cocrystal 2 has an exothermic peak at 221 °C. Both cocrystals are insensitive energetic explosives (IS > 40 J, FS > 360 N). Methylimidazole compounds are rarely used as coformers to form cocrystals with CL‐20, which possess good properties for a range of potential applications. Herein, we provide new possible directions for enriching cocrystal speciation.
Evolution of Immigration-Control Policies in France, Italy, and Spain
Authors: Vickstrom Erik R.
Published: April 2019

Senegalese migration is a useful case to study because Senegalese migrants are present in many different contexts of reception. They have long migrated to destinations within Africa, including neighboring countries such as the Gambia and Guinea and more-distant destinations such as Angola, the Democratic Republic of the Congo, and South Africa (Bredeloup 1993). While France was the main destination of Senegalese intercontinental emigration during most of the twentieth century, Senegalese migrants have since diversified their mobility to include many countries in Europe, North America, and Asia. Indeed, most Senegalese who travel abroad can recount stories of meeting other Senegalese in the markets of Nairobi, the cafés of Paris, the New York subway, or the streets of Bangkok.
Pathways into Irregular Legal Status of Senegalese Migrants France, Italy, and Spain
Authors: Vickstrom Erik R.
Published: April 2019

“Illegal” migration is a major concern in most immigrant-receiving countries, yet most policy and much research on the topic is hampered by a lack of data and a misunderstanding of the origins and trajectories of so-called undocumented migrants’ legal statuses. Irregular migration is difficult to measure empirically, as it, by definition, escapes the detection of most states’ immigration-control bureaucracies. In addition, many surveys have difficulty in sampling what is a mostly hidden population. This lack of data has undoubtedly contributed to an even bigger problem in the study of irregular migration: the conflation of undocumented border crossing with the broader phenomenon of irregularity of legal status. In reality, clandestine border crossing is but one pathway among many into irregular legal status and may not even be the most important one in many countries. Furthermore, immigration policies actively produce these pathways into irregularity through restrictive control mechanisms. A more thorough understanding of the implications of irregularity for both destination societies and for the migrants themselves must therefore study multiple pathways into irregular status.
Legal Status, Territorial Confinement, and Transnational Activities of Senegalese Migrants in France, Italy, and Spain
Authors: Vickstrom Erik R.
Published: April 2019

Migrants have long maintained ongoing social, economic, and political connections with their homelands, but these transnational activities have garnered increased attention from scholars and policymakers in recent years. Academic research has shown that modern travel and communications technologies have created new kinds and quantities of transnational engagement, findings which have challenged the notions of the state control of borders and of unidirectional immigrant settlement and assimilation. At the same time, international development agencies and sending-country governments have begun to recognize the potential of migrants to be active participants in the development of their home communities. Such “co-development” strategies seek to leverage migrant cross-border activities, such as remittances, investment, and participation in hometown associations, as part of overall development strategies.
Basic Schools in Each and Every Parish: The School Act of 1842 and the Rise of Mass Schooling in Sweden
Authors: Westberg Johannes
Published: April 2019

This chapter examines the preconditions, content, and consequences of the school act of 1842, which was the main primary school legislation in nineteenth-century Sweden. This chapter shows that the school act defined a school system that placed the main responsibility for funding and organizing schools in the hands of Sweden’s parishes. Although the school act did not make schooling mandatory for all children, it required all parishes to establish at least one school. As a result, schools were soon distributed throughout Sweden, although the teaching that children received remained limited in terms of attendance, content, and the length of the school year.
General fluctuations of the type II pure spinor string on curved backgrounds
Authors: Chandia Osvaldo
Published: April 2019

Abstract

The general fluctuations, in the form of vertex operators, for the type II superstring in the pure spinor formalism are considered. We review the construction of these vertex operators in flat space-time. We then review the type II superstrings in curved background in the pure spinor formalism to finally construct the vertex operators on a generic type II supergravity background.