bluuebunny/crossref_metadata_2025 huggingface dataset:
Germline mosaicism in an α‐thalassemia family: Incidental identification by prenatal ultrasound
Authors: Xu Li‐Li , Liu Ying‐Na , Zhen Li , Li Dong‐Zhi
Published: July 2019

What's already known about this topic?

In almost all cases of Hb Bart's hydrops fetalis, α0‐thalassemia can be confirmed by testing of parental blood.

Germline mosaicism occurs most of the time in autosomal dominant and X‐linked recessive disorders.

What does this study add?

The present case is the first documentation of germline mosaicism for an α‐thalassemia deletion.

Since almost all fetuses affected with Hb Bart's hydrops fetalis present with cardiomegaly on ultrasound, sonographers in regions with high α‐thalassemia prevalence should be sensitive to the cardiothoracic ratio.
Concordance of hospitalizations between Clinical Practice Research Datalink and linked Hospital Episode Statistics among patients treated with oral antidiabetic therapies
Authors: Saine M. Elle , Carbonari Dean M. , Newcomb Craig W. , Gallagher Arlene M. , Blak Betina T. , Roy Jason A. , Wood Jennifer , Cardillo Serena , Hennessy Sean , Strom Brian L. , Lo Re Vincent
Published: July 2019

Purpose

The ability of the Clinical Practice Research Datalink (CPRD) to ascertain all‐cause hospitalizations remains unknown. We determined the proportion of hospitalizations in CPRD that were also recorded in Hospital Episode Statistics (HES), and vice versa, among patients initiating oral antidiabetic (OAD) therapy.

Methods

We conducted a retrospective cohort study from October 2009 to September 2012 among OAD‐treated patients registered with general practitioners who contribute to CPRD and consent to HES linkage. In CPRD, we identified initial hospitalizations for each calendar year by an Inpatient Referral, Consultation Type code, or Read code indicating an inpatient episode and determined if an admission date was recorded in HES within ±30 days. We then identified initial HES admission dates and determined if a hospitalization was documented in CPRD within ±30 days. Sensitivity analyses were conducted utilizing HES discharge, rather than admission, dates.

Results

Among 8574 OAD‐treated HES‐linked patients in CPRD, 6574 initial hospitalizations across the study period were identified in CPRD, and 5188 (78.9% [95% CI, 77.9%‐79.9%]) were confirmed by a HES admission date within ±30 days (median difference, ±3 days [IQR, 1‐7 days]). Among 8609 initial hospital admissions in HES, 4803 (55.7% [95% CI, 54.7%‐56.8%]) hospitalizations were recorded in CPRD within ±30 days (median difference, ±4 days [IQR, 1‐9 days]). Similar results were observed using HES discharge dates.

Conclusion

A substantial minority of patient‐level hospitalization data are nonconcordant between HES and CPRD. Pharmacoepidemiologic studies within CPRD that seek to identify hospitalizations should consider linkage with HES to ensure adequate ascertainment of inpatient events.
National trends in hydroxyurea and opioid prescribing for sickle cell disease by office‐based physicians in the United States, 1997‐2017
Authors: Su Zhuo Tony , Segal Jodi Beth , Lanzkron Sophie , Ogunsile Foluso Joy
Published: July 2019

Purpose

To identify trends in physician drug prescribing practices for sickle cell disease (SCD).

Methods

We used data from the National Disease and Therapeutic Index to evaluate medications prescribed to children (definition: aged 19 years or younger) and adults (20 years or older) with SCD by office‐based physicians in the United States during 1997 to 2017. Prescriptions were evaluated in 3‐year intervals.

Results

The proportion of SCD visits that included new/continued hydroxyurea prescriptions increased from less than or equal to 8% before 2009 to 33% in 2015 to 2017. The increase was significant in visits by children (2.5% in 1997‐1999 to 47% in 2015‐2017; P = .003 by Spearman's rank‐order correlation) but not in adults (6.9% to 11%; P = .12). Opioids, started/continued in 13% (lowest 3‐year average) to 35% (highest) of visits by children and 55% to 81% of visits by adults, remained the most frequently prescribed medications for SCD overall. There were no significant changes over time in opioid prescribing for adults (P = .64) or children (P = .38). Hematologists/oncologists accounted for a higher proportion of visits by children (67.2% over 1997‐2017) than adults (25.2%), while emergency medicine visits were higher in adults (14.0%) than children (2.6%).

Conclusions

This study suggests a robust increase in hydroxyurea prescribing for children with SCD. The BABY HUG trial, which demonstrated safety and efficacy of starting hydroxyurea in infancy and informed current SCD guidelines recommending broader use in children, may have contributed to this increase. However, hydroxyurea prescribing for adults remains infrequent and considerably lower than opioids. Barriers in access to specialist care persist for adults with SCD.
Influence of Interventions on Daily Physical Activity and Sedentary Behavior after Stroke: A Systematic Review
Authors: Kringle Emily A. , Barone Gibbs Bethany , Campbell Grace , McCue Michael , Terhorst Lauren , Kersey Jessica , Skidmore Elizabeth R.
Published: July 2019

Background

Evidence suggests that frequent engagement in daily activities requiring physical activity may influence risk factors for recurrent stroke. The effects of nonpharmacological interventions on daily physical activity levels and sedentary behavior are unclear.

Objective

To describe the effects of interventions on levels of daily physical activity and sedentary behavior among people with stroke.

Methods

OVID/Medline, CINAHL, PsycINFO, and the Cochrane Database were searched using the following search terms: stroke, rehabilitation, intervention, sedentary, physical activity, lifestyle, self‐management, and exercise. Data extraction and risk of bias assessment were conducted by two authors.

Results

Thirty‐one interventions were identified that included exercise, behavior change techniques, and education components. These components were delivered alone and in varying combinations. At postintervention, between‐group effects on change scores (Cohen's d = 0.17–0.75, P < .05) or between‐group differences in odds of participating in daily physical activity (odds ratio [OR] = 2.07, P < .05) were detected in six studies, and within‐group effects in nine studies (Cohen's d = 0.21–3.97, P < .05). At follow‐up, between‐group differences in odds of participating in daily physical activity were detected in one study (OR = 2.64, P < .05), and within‐group effects in two studies (Cohen's d = 0.25, P < .05). No effects (P < .05) were detected in 17 studies.

Conclusion

It may be possible to modify daily physical activity levels and sedentary behavior poststroke; however, there is insufficient evidence to suggest the superiority of a particular intervention approach. Future studies should explore the unique contributions of individual intervention components to guide development of parsimonious multicomponent interventions that are effective for promoting daily physical activity and reducing sedentary behavior among people with stroke.

Level of Evidence

I.
Spanish multicentre study on morbidity and pathogenicity of tracheal bronchus in children
Authors: Moreno Marcela , Castillo‐Corullón Silvia , Pérez‐Ruiz Estela , Luna Maria Carmen , Antón‐Pacheco Juan L. , Mondejar‐Lopez Pedro , De‐la‐Serna Olga , Villa José‐Ramón , Osona Borja , Torres‐Borrego Javier , Santiago‐Burruchaga Mikel , Asensio Oscar , Andres‐Martin Anselmo , Delgado‐Pecellin Isabel , González Yolanda , Palmero Ana , Escribano Amparo
Published: July 2019

Tracheal bronchus (TRB) has been generally considered an anatomical variant of the tracheobronchial tree without a precise pathological effect. Its prevalence is estimated to be between 0.2% to 3% of all children undergoing bronchoscopy and scientific information has been limited to case reports or small case series. Our working hypothesis was that TRB could trigger by itself recurrent or persistent respiratory symptoms. The objective of this retrospective and multicentre study of children with a diagnosis of TRB, coming from the main paediatric pulmonology units of Spain, was to determine the anatomical and clinical characteristics, including comorbidities, of TRB in childhood and their impact in the patients' clinical outcomes. One hundred thirty‐three patients from 13 institutions were included in the study. Mean diagnostic age was 3.4 years and flexible bronchoscopy was the initial diagnostic method in 85% of cases. All TRB were located on the right wall of the trachea: 76% in the lower third and 24% in the carina. The most common clinical manifestations were obstructive bronchitis (53.3%) and recurrent pneumonia (46.6%), usually affecting the right upper lobe. Regarding associated anomalies, 33% had tracheomalacia, 32% congenital cardiovascular malformations, 28% gastroesophageal reflux, 22.5% congenital tracheal stenosis, and 8.3% Down syndrome. This series appears to be the most extensive published to date addressing this topic and, according to our data, TRB does not appear to be a mere incidental finding but is more likely linked to a wide range of congenital anomalies and contributes by itself to the recurrent respiratory symptomatology that these children exhibit.
Linoleic acid‐rich guava seed oil: Safety and bioactivity
Authors: Prommaban Adchara , Utama‐ang Niramon , Chaikitwattana Anan , Uthaipibull Chairat , Srichairatanakool Somdet
Published: July 2019

Guava (Psidium guajava) is a widely consumed fruit and has been commercialized in markets. The seeds are by‐products of the processing procedures performed by the commercial guava juice industry. They are considered a nutritional resource that has been poorly utilized as they contain essential fatty acids such as linoleic acid (LA) and phenolics in abundance. In the study, guava seed oil (GSO) was used, which was obtained by hexane extraction of guava seeds to determine composition and test toxicity, cell migration, cancer cell viability, and plasmodium growth. GSO was found to be relatively nontoxic to normal hepatocytes and peripheral blood mononuclear cells, with mice for 14 days showing median lethal dose (LD50) > 10 mg/kg and rats for up to 90 days. Surprisingly, the oil inhibited the proliferation of the human erythroleukemic cells in a dose‐dependent manner with the half maximal inhibitory concentration values of 155 and 137 μg/ml at 24 and 48 hr, respectively. Importantly, GSO at 500 μg/ml was found to increase the degree of migration of keratinocytes (HaCaT). These observations suggest that edible P. guajava seed oil, which is abundant with linoleic acid and antioxidants, can promote skin wound healing and inhibit the proliferation of leukemic cells.
Comparison of pathological outcomes between robotic rectal cancer surgery and laparoscopic rectal cancer surgery: A meta‐analysis based on seven randomized controlled trials
Authors: Liao Guixiang , Zhao Zhihong , Deng Haijun , Li Xianming
Published: July 2019

Objective

To compare the pathologic outcomes between robotic‐assisted rectal cancer surgery (RRCS) and laparoscopic rectal cancer surgery (LRCS) based on randomized controlled trials (RCTs).

Methods

Electronic databases were searched from their inception to 7 October 2018, for RCTs involving a comparison between RRCS and LRCS. Positive circumferential resection margin (CRM), distance to the distal margin, proximal margin, the rate of complete mesorectal excision, and harvested lymph nodes were interesting of outcomes.

Results

The positive CRM, proximal margin, and rate of complete mesorectal excision were comparable between the two techniques. RRCS resulted in better outcomes for the distance to the distal margin (mean difference: 0.83 cm, 95% confidence interval, 0.29‐1.37, P = .003).

Conclusions

The pathologic outcomes associated with the two approaches were comparable, with RRCS showing better outcomes for the distance to the distal margin. However, additional well‐designed studies are needed to assess whether the benefits of pathologic outcomes improve survival outcomes.
Functional Outcomes Following Microfragmented Adipose Tissue Versus Bone Marrow Aspirate Concentrate Injections for Symptomatic Knee Osteoarthritis
Authors: Mautner Kenneth , Bowers Robert , Easley Kirk , Fausel Zachary , Robinson Ryan
Published: July 2019

This study aimed to determine whether autologous orthobiologic tissue source affects pain and functional outcomes in patients with symptomatic knee osteoarthritis (OA) who received microfragmented adipose tissue (MFAT) or bone marrow aspirate concentrate (BMAC) injection. We retrospectively reviewed prospectively collected data from patients who received BMAC or MFAT injection for symptomatic knee OA. Patients completed baseline and follow-up surveys. Each survey included the Knee Injury and Osteoarthritis Outcome Score (KOOS) questionnaire, Emory Quality of Life (EQOL) questionnaire, and Visual Analog Scale (VAS) for pain. The follow-up responses were compared with baseline for all patients and between BMAC and MFAT groups. A total of 110 patients met inclusion criteria, with 76 patients (BMAC 41, MFAT 35) and 106 knees (BMAC 58, MFAT 48) having appropriate follow-up data. The BMAC group included 17 females and 24 males, with a mean age of 59 ± 11 years. The MFAT group included 23 females and 12 males, with a mean age of 63 ± 11 years. Minimum follow-up time was 0.5 years. Mean follow-up time was 1.80 ± 0.88 years for BMAC and 1.09 ± 0.49 years for MFAT. Both groups had significant improvement in EQOL, VAS, and all KOOS parameters preprocedure versus postprocedure (p < .001). There was not a significant difference when comparing postprocedure scores between groups (p = .09, .38, .63, .94, .17, .15, .70, respectively). These data demonstrate significant improvement in pain and function with both MFAT and BMAC injections in patients with symptomatic knee OA without a significant difference in improvement when comparing the two autologous tissue sources. Stem Cells Translational Medicine  2019;8:1149–1156
Embracing green innovation via green supply chain learning: The moderating role of green technology turbulence
Authors: Lisi Wei , Zhu Rui , Yuan Chunlin
Published: July 2019

With the increasingly serious environmental contamination and growingly stringent regulatory pressures, firms should embrace green innovation by learning from their supply chain partners. Although green supply chain learning has been suggested to be a crucial approach for enhancing innovative capability, whether and under what conditions it affects green innovation is still unclear. This study investigates the influence of two dimensions of green supply chain learning (i.e., green supplier and customer learning) on two types of green innovation (i.e., green product and process innovation) and the moderating role of green technology turbulence. Survey data collected from 249 Chinese firms were used to test research hypotheses. The findings show that both green supplier and customer learning positively influence green product and process innovation. However, green technology turbulence moderates these relationships differently. Specifically, green technology turbulence strengthens the impacts of green customer learning on green product and process innovation, while weakens the impact of green supplier learning on green process innovation. The moderating effect of green technology turbulence on the link between green supplier learning and green product innovation is insignificant. These results highlight the importance of learning from supply chain partners for sustainable development and firms' agility in adapting to external technological conditions in implementing their environmental practices.
Sustainable development and economic performance: Gaps and trends for future research
Authors: do Prado Guilherme Francisco , Piekarski Cassiano Moro , da Luz Leila Mendes , de Souza Jovani Taveira , Salvador Rodrigo , de Francisco Antonio Carlos
Published: July 2019

The aim of this paper is to determine the existence of gaps in the literature, by investigating studies that statistically analyzed the relationship between sustainable development and economic performance. A literature review was conducted in the Web of Science and Scopus databases. The study analyzed the authors, publication years, journals involved, methodologies used, and results obtained. The identified gaps and opportunities were (a) opportunity to create or employ different measurements for financial, social, and environmental performance and (b) to use different kinds of control or moderating variables, in order to further explore the relationship between sustainable development and financial performance.
Enzyme‐Assisted Extraction of Triterpenoid Saponins from Pseuderanthemum palatiferum (Nees) Radlk. Dry Leaf Powder and Bioactivities Examination of Extracts
Authors: Huy Tran Bao , Lien Phuong Nguyen Thi , Nga Bui Kim , Oanh Huynh Ngoc , Hieu Nguyen Huu
Published: July 2019

Triterpenoid saponins were extracted from of Pseuderanthemum palatiferum (Nees) Radlk. dry leaf powder by using enzyme‐assisted extraction method. Effects of single factors on total saponins content (TSC) were investigated. Then, a full factorial design with two levels was conducted to screen the main factors affecting TSC. Two main factors as extraction temperature and time were determined. Response Surface Methodology with central composite design was used to study simultaneous effects of these factors on TSC. Results showed that the optimum conditions were 54.9 °C and 80.8 min. The extract under these conditions was tested with bioactivities. The extract had the haemolytic index of 256.74 mL, anti‐inflammatory activity with IC20 of 0.56 μg/mL, anti‐oxidation activity with IC50 values of DPPH, ABTS, and hydroxyl of 61.47, 1.42, and 30.33 μg/mL, respectively, and cytotoxicity on cancer cell line HepG2. Accordingly, triterpenoid saponins from Pseuderanthemum palatiferum (Nees) Radlk. could be considered as a valuable constituent.
Kinetics of Thermal Degradation of Non‐Woven Plastics: Model‐Free Kinetic Approach
Authors: Patnaik Satyanarayan , Kumar Sachin , Panda Achyut K.
Published: July 2019

The thermo‐degradative behaviour of non‐woven plastics was studied in order to analyze their thermal stability and subsequent recycling method. Non‐isothermal thermogravimetric experiments using wide range of heating rates of 10, 20, 40, 60, 80,100 °Cmin−1 have been performed from ambient to 900 °C in a thermo‐balance with the objective of determining the kinetic parameters. Four model free kinetic approaches such as Friedman method, Coats‐Redfern (modified) method, Flynn–Wall–Ozawa (FWO) method and Kissinger method have been used to determine kinetic parameters for the two stage degradation of the non‐woven plastic sample including the thermal degradation of synthetic plastics in the first step followed by the subsequent degradation of inorganic fillers in the second step. The activation energy obtained for first stage degradation is found significantly lower (106‐112 kJ/mol) compared to the second stage degradation (191‐202 kJ/mol). This result would help design a process for the valorisation of synthetic polymer and segregation of the filler materials in the plastic sample to be reused further.
The Role of Polyaniline Molecular Structure in Producing High‐Performance Fe‐N‐C Catalysts for Oxygen Reduction Reaction
Authors: He Qian , Chen Xiuhong , Jia Fengqiu , Ding Wei , Zhou Yuanyuan , Wang Jian , Song Xiaoyun , Jiang Jinxia , Liao Qiang , Li Jing , Wei Zidong
Published: July 2019

The precise control of nano‐structure and increase active sites density are of crucial importance for the pyrolyzed Fe‐N−C catalysts′ performance optimization. Herein, the relationship between molecular structures of PANI precursors and the activity for oxygen reduction reaction (ORR) of the derived Fe‐N−C catalysts is investigated. The PANI molecular structure, especially the content of quinoid rings (QR), is controlled by varying molar ratios of ammonium persulfate (APS) to aniline monomers (AN). With the increase of APS/AN ratio from 0.5 to 4, the oxidation degree together with the QR content of PANI increases. Accordingly, the produced catalysts’ morphology experiences an evolution from bulk, nanotube to flower‐like structure. And the ORR activity shows volcano‐relationship with the increase of the QR content in PANI precursors. Specifically, when APS/AN=2.5, the derived PANI with moderate QR content benefits to produce Fe‐N−C catalyst which shows the maximum ORR activity with a half‐wave potential of 0.74 V (vs RHE) in acidic electrolyte among the produced catalysts. Moreover, two opposite effects with the increasing QR content are revealed; i) the QR benefits the Fe coordination and Fe−Nx active sites formation which enhances the activity, and ii) the accompanying formed oligomers decrease the thermal stability and thus decrease the number of active sites.
Unravelling the Dynamic Capture of Antibiotics by Conjugated Microporous Polymers
Authors: Li Li , Ge Lei , Chen Shiqian , Yuan Hao , Min Yuxiang , Xu Lai
Published: July 2019

The encapsulation of antibiotic molecules in conjugated microporous polymers is investigated by using the density functional theory (DFT) method and molecular dynamics (MD) simulations. We find that guest molecules are firstly wrapped around the edges of the polymer nanopores, and as the number of guest molecules increases, they begin to move from the edge to the center of the pore to further stabilize the complex. We discover a parallel sandwich‐type encapsulation model, it is the most stable configuration in which the guest molecules reside in the host framework, and the pore size of the host framework also changes with the entry of guest molecules. The significantly strong adsorption of antibiotics to CMP can be ascribed to charge transfer between the electron‐rich groups and electron‐withdrawing groups. These detailed insights would promote the design of new conjugated microporous polymers for the adsorption of antibiotics, which may provide new opportunities for the treatment of water pollution caused by antibiotics.
Study on Profile Control and Water Shut‐Off Performance of Interpenetrating Network Polymer Gel Composite System in Shallow Low Temperature Fractured Oil Layer
Authors: Fang Yujia , Yang Erlong , Cui Xiaona
Published: July 2019

In order to solve the problem/address the issue of oil saturation reduction in the near‐wellbore region of low‐temperature fractured reservoir in Fuyu oilfield, it is especially necessary to carry out in‐depth profile control plugging technology research. In this paper, composite system of particle plugging agent and new interpenetrating network gel were optimally designed, and the non‐fractured cores and fractured cores were used for plugging experiment and oil displacement, the in‐depth profile control mechanism of the composite system was obtained. The results show that the gelation time of the new interpenetrating network gel system can reach 6–7 hours under low temperature conditions (30 °C), with strong shear resistance and viscosity retention. The waterflooding efficiency of fractured core is lower than that of non‐fractured core. After injection of different profile control system, improved recovery efficiency of fractured core is larger than that of non‐fractured core, but the ultimate oil recovery of fractured core is still smaller than that of non‐fractured core. The gelation effect and strength of the composite system are better than that of new interpenetrating network gel agent. The addition of the expanded particles in the system greatly enhances the overall strength and anti‐interference ability. This study can provide theoretical guidance for in‐depth profile control of low temperature fractured reservoirs.
A pH‐Tailored Anodic Deposition of Hydrous RuO2 for Supercapacitors
Authors: Lin Jun , Xu Youlong , Wang Jie , Zhang Baofeng , Li Liang , Wang Xinzhi , He Shengnan , Zhu Jianbo
Published: July 2019

A pH‐tailored anodic deposition strategy is reported in this work, by which the hydrous ruthenium oxide (RuO2) can be directly deposited on titanium (Ti) substrates. The prepared RuO2 electrode exhibits a well kinetic performance (the remarkably low equivalent series resistance of Res∼2 mΩ and charge transfer resistance of Rct∼0.11Ω) and a high specific capacitance of 756 F g‐1 at 0.6 A g‐1. More importantly, a symmetric supercapacitor based on the RuO2 electrode delivers a high specific energy of 24 Wh kg‐1 at 150 W kg‐1. Even at a large specific power of 26.25 kW kg‐1, specific energy is still as high as 8.6 Wh kg‐1, meanwhile achieving a long lifespan of 98% retention over 100,000 cycles. All of these distinguishing properties not only enable the prepared RuO2 to be an excellent electrode material for high‐power output and long life supercapacitors, but also indicates that the pH‐tailored anodic deposition strategy reported in this work is effective to prepare high‐performance RuO2 electrode.
Dealing with revered past: Historical identity statements and strategic change in Japanese family firms
Authors: Sasaki Innan , Kotlar Josip , Ravasi Davide , Vaara Eero
Published: July 2019

Research Summary

This paper examines how strategy‐makers attempt to reconcile change initiatives with organizational values and principles laid out long before, still encased in strategic identity statements such as corporate mottos and philosophies. It reveals three discursive strategies that strategy‐makers use to establish a sense of continuity in time of change: elaborating (transferring part of the content of the historical statement into a new one), recovering (forging a new statement based on the retrieval and re‐use of historical references), and decoupling (allowing the co‐existence of the historical statement and a contemporary one). By so doing, our study advances research on uses of the past, establishes important linkages between identity and strategy research, and enhances our understanding of the intergenerational transfer of values in family firms.

Managerial Summary

Crafting a new corporate philosophy or mission statement can help implement strategic change, but can also be experienced as a disruption in people's sense of “who we are” as an organization. This paper reveals a variety of strategies that managers can use to deal with the tension between promoting change and maintaining a sense of continuity with a distant, revered past. By doing so, it helps managers confronting these issues deal with the enabling and constraining effects of the past. While this is a more general challenge for organizations with historical legacies, it is a particularly delicate issue for family firms grappling with the need to transfer values from one generation to the next, while retaining flexibility to change and adapt over time.
Problemistic search distance and entrepreneurial performance
Authors: Angus Ryan W.
Published: July 2019

Research Summary

This paper seeks to extend the problemistic search literature by investigating how far entrepreneurial organizations seeking to improve their chances for success should search, depending on their level of past performance. Drawing on a novel data set from the Google Play app store, the paper finds support for its hypothesis that past performance moderates the relationship between search distance and subsequent performance. As past performance increases, the less beneficial (and potentially more harmful) nonlocal search becomes. While the majority of app developers choose a nonlocal search strategy in response to low first app performance, this is rarely the best choice. Instead, the highest second app performance outcomes are associated with moderate search distances that fall between local and nonlocal extremes.

Managerial Summary

This paper uses a large data set obtained from the Google Play app store to explore the following question: when a nascent app developer's first app performs poorly, how different should its second app be? By comparing the text descriptions of developers' first and second apps, the paper is able to show that as the performance of a first app increases, the more harmful it becomes to make a very different second app. Only at extremely low levels of first app performance is it beneficial for developers to make second apps that are very different from their first apps. In all other cases, making second apps that are moderately different—rather than very similar or very different—is associated with the highest second app performance.
Disentangling the microfoundations of acquisition behavior and performance
Authors: Meyer‐Doyle Philipp , Lee Sunkee , Helfat Constance E.
Published: July 2019

Research Summary

The acquisition literature has highlighted that both firm‐level and manager‐level factors shape acquisition outcomes, yet little is known about their relative contribution. We conduct a variance decomposition analysis to explore the contribution of CEO‐level versus firm‐level factors to acquisition behavior and performance. We also extend the methodology of variance decomposition in strategic management research by employing Poisson multi‐level models, and deriving the percentage of variance attributable to each level in a four‐level model. Although CEO and firm effects both explain a substantial share of the variance in acquisition behavior, the CEO‐effect is notably larger. CEO‐level factors also drive a large portion of the variance in acquisition performance. Overall, our study contributes to the literatures on acquisitions and variance decomposition, and has implications for dynamic capabilities.

Managerial Summary

How much do firm‐level factors and CEO‐level factors matter for explaining acquisition behavior and acquisition performance? This question is not only relevant for researchers but also for practitioners who seek to better understand what drives acquisitions and their outcomes. To help answer this question, our study conducts a variance decomposition analysis of acquisition behavior and acquisition performance. We find that both CEO‐level factors and firm‐level factors explain a substantial portion of the variance in acquisition behavior, but that CEO‐level factors matter relatively more. We also find that CEO‐level factors also explain a substantial portion of the variance in acquisition performance.
Integrating Fluorinated Polymer and Manganese‐Layered Double Hydroxide Nanoparticles as pH‐activated 19F MRI Agents for Specific and Sensitive Detection of Breast Cancer
Authors: Zhang Cheng , Li Li , Han Felicity Y. , Yu Xinying , Tan Xiao , Fu Changkui , Xu Zhi Ping , Whittaker Andrew K.
Published: July 2019

19F magnetic resonance imaging (19F MRI) agents capable of being activated upon interactions with cancer triggers are attracting increasing attention, although challenges still remain for precise and specific detection of cancer tissues. In this study, a novel hybrid 19F MRI agent for pH‐sensitive detection of breast cancer tissues is reported, a composite system designed by conjugating a perfluoropolyether onto the surface of manganese‐incorporated layered double hydroxide (Mn‐LDH@PFPE) nanoparticles. The 19F NMR/MRI signals from aqueous solutions of Mn‐LDH@PFPE nanoparticles are quenched at pH 7.4, but “turned on” following a reduction in pH to below 6.5. This is due to partial dissolution of Mn2+ from the Mn‐LDH nanoparticles and subsequent reduction in the effect of paramagnetic relaxation. Significantly, in vivo experiments reveal that an intense 19F MR signal can be detected only in the breast tumor tissue after intravenous injection of Mn‐LDH@PFPE nanoparticles due to such a specific activation. Thus pH‐activated Mn‐LDH@PFPE nanoparticles are a potential “smart” 19F MRI agent for precise and specific detection of cancer diseases.
Lithiumpyridinyl‐Driven Synthesis of High‐Purity Zero‐Valent Iron Nanoparticles and Their Use in Follow‐Up Reactions
Authors: Egeberg Alexander , Block Theresa , Janka Oliver , Wenzel Olivia , Gerthsen Dagmar , Pöttgen Rainer , Feldmann Claus
Published: July 2019

The synthesis of zero‐valent iron (Fe(0)) nanoparticles in pyridine using lithium bipyridinyl ([LiBipy]) or lithium pyridinyl ([LiPy]) is presented. FeCl3 is used as the most simple starting material and reduced either in a [LiBipy]‐driven two‐step approach or in a [LiPy]‐driven one‐pot synthesis. High‐quality nanoparticles are obtained with uniform, spherical shape, and mean diameters of 2.9 ± 0.5 nm ([LiBipy]) or 4.1 ± 0.7 nm ([LiPy]). The as‐prepared, high purity Fe(0) nanoparticles are monocrystalline. In addition to particle characterization (high‐resolution transmission electron microscopy, scanning transmission electron microscopy, dynamic light scattering), composition and purity are examined in detail based on electron diffraction, X‐ray powder diffraction, elemental analysis, infrared spectroscopy, 57Fe Mössbauer spectroscopy, and magnetic measurements. Due to their small size and high purity, the Fe(0) nanoparticles are highly reactive. They can be used in follow‐up reactions to obtain a variety of iron compounds, which is exemplarily shown for the transformation to iron carbide (Fe3C) nanoparticles, the reaction with sulfur to obtain FeS nanoparticles, or the direct reaction with pentamethylcyclopentadiene to FeCp*2 (Cp*: pentamethylcyclopentadienyl).
Large‐Area, Uniform, Aligned Arrays of Na3(VO)2(PO4)2F on Carbon Nanofiber for Quasi‐Solid‐State Sodium‐Ion Hybrid Capacitors
Authors: Mao Zhifei , Wang Rui , He Beibei , Gong Yansheng , Wang Huanwen
Published: July 2019

Sodium–vanadium fluorophosphate (Na3V2O2x(PO4)2F3−2x, NVPF, 0 ≤ x ≤ 1) is considered to be a promising Na‐storage cathode material due to its high operation potentials (3.6–4 V) and minor volume variation (1.8%) during Na+‐intercalation. Research about NVPF is mainly focused on powder‐type samples, while its ordered array architecture is rarely reported. In this work, large‐area and uniform Na3(VO)2(PO4)2F cuboid arrays are vertically grown on carbon nanofiber (CNF) substrates for the first time. Owing to faster electron/ion transport and larger electrolyte–electrode contact area, the as‐prepared NVPF array electrode exhibits much improved Na‐storage properties compared to its powder counterpart. Importantly, a quasi‐solid‐state sodium‐ion hybrid capacitor (SIHC) is constructed based on the NVPF array as an intercalative battery cathode and porous CNF as a capacitive supercapacitor anode together with the P(VDF‐HFP)‐based polymer electrolyte. This novel hybrid system delivers an attractive energy density of ≈227 W h kg−1 (based on total mass of two electrodes), and still remains as high as 107 Wh kg−1 at a high specific power of 4936 W kg−1, which pushes the energy output of sodium hybrid capacitors toward a new limit. In addition, the growth mechanism of NVPF arrays is investigated in detail.
Potential benefits of polysaccharides derived from marine alga Ulva lactuca against hepatotoxicity and nephrotoxicity induced by thiacloprid, an insecticide pollutant
Authors: Kammoun Intissar , Sellem Imen , Ben Saad Hajer , Boudawara Tahia , Nasri Moncef , Gharsallah Neji , Mallouli Lotfi , Amara Ibtissem Ben
Published: July 2019

The present study aimed to evaluate the potential protective and antioxidant effect of polysaccharides (PS) extracted from Ulva lactuca against thiacloprid (THC) induced nephrotoxicity and hepatotoxicity. The antioxidant capacity of PS was tested in vitro using ABTS radical scavenging activity and plasmid DNA cleavage assays andin vivo on adult male rats treated for 30 days. Animals were allocated into four groups: control; THC (22.5 mg/kg); THC (22.5 mg/kg) + PS1 (100 mg/kg diet); and THC (22.5 mg/kg) + PS2 (200 mg/kg diet). The structural features of PS were determined by Fourier transformed infrared (FT‐IR), UV absorption peak detection, high performance liquid chromatography (HPLC) and gel permeation chromatography, and also functional properties were investigated. Overall, results indicated that THC increased significantly malondialdehyde, advanced oxidation protein products, glutathione levels, which is correlated with severe histological and plasmatic biochemical injuries in both liver and kidney tissues. However, cotreatment PS induced a significant protective and healing affects against the nephrotoxicity and hepatotoxcity induced by THC.
Surrogate models for parameterized representation of wake‐induced loads in wind farms
Authors: Dimitrov Nikolay
Published: July 2019

A procedure for mapping wake‐induced load predictions computed with the dynamic wake meandering model to a computationally efficient surrogate model approximation is defined and demonstrated. Using the mapping function, the load variation can be efficiently estimated for a wind farm with arbitrary layout. The resulting load assessment procedure provides continuous, differentiable output with known analytical derivatives and can be used for applications such as wind turbine layout optimization, estimation of turbine lifetime, and uncertainty analysis.
European Union retail electricity markets in the Green Transition: The quest for adequate design
Authors: Boscán Luis R.
Published: July 2019

After a gradual process of reforms, retail electricity markets in Europe are well established. In parallel, the decarbonization agenda and rapid technological progress lead the way toward a renewable‐based and distributed electricity system, in which new business models emerge. Distributed resources, prosumers, and peer‐to‐peer trading are all part of the most likely future scenarios. The newly adopted Clean Energy Package, put forward by the European Commission in 2016, responded to the consensus that existing electricity markets needed to adapt and aimed at putting consumers at the center. But will the ongoing reforms live up to the challenges posed by the coming stages of the ongoing Green Transition? While most recent analyses focus on wholesale issues, the present review narrows this gap. We analyze the European Union (EU) retail electricity market design in isolation, but also in its interaction with the renewable energy policy. We compare the current and the forthcoming legislative framework to elucidate if the recently adopted reforms mitigate conflicts or facilitate complementarities arising from the implementation of the European energy policy framework. While the reforms remove fundamental barriers for consumer participation, several unresolved conflicts remain. Thus, looking forward, there is a significant implementation challenge. Among these are the overdue task of making competition effective, striking the right balance between the verticality and horizontality of the future retail market and confronting market reconfiguration. In this respect, the paper makes several policy recommendations aimed at EU Member States, which are also valid for any jurisdiction willing to advance a transition to renewables.

This article is categorized under:

Energy and Climate > Economics and Policy

Energy Systems Economics > Economics and Policy

Energy Policy and Planning > Economics and Policy
Building a Large Robotic Thoracic Surgery Program in an Emerging Country: Experience in Brazil
Authors: Terra Ricardo Mingarini , Haddad Rui , de Campos José Ribas Milanese , de Araújo Pedro Henrique Xavier Nabuco , Lima Carlos Eduardo Teixeira , Braga Felipe , Bibas Benoit Jacques , Trindade Juliana Mol , Lauricella Leticia Leone , Pêgo‐Fernandes Paulo Manuel
Published: July 2019

Background

In the last decade, robotic video‐assisted thoracic surgery (R‐VATS) has grown significantly and consolidated as an alternative to video‐assisted thoracic surgery. The objective of this study is to present the implementation as well as the experience with R‐VATS accumulated by 2 Brazilian groups. We also compared the outcomes of procedures performed during the learning curve and after a more mature experience.

Methods

Retrospective cohort study included all R‐VATS procedures performed since April 2015 until April 2018. We describe the process of implantation of robotic surgery, highlighting the peculiarities and difficulties found in a developing country. Moreover, we reported our descriptive results and compared the first 60 patients to the subsequent cases.

Results

Two hundred and five patients included 101 females/104 males. Mean age was 61.7 years. There were hundred and sixty‐four pulmonary resections, 39 resections of mediastinal lesions, 1 diaphragmatic plication, and 1 resection of a hilar tumor. Median operative times were 205 min for lung resections and 129 min for mediastinal. There was no conversion to VATS or thoracotomy or major intraoperative complications. Median length of stay was 3 days for pulmonary resections and 1 day for mediastinal. Postoperative complications occurred in 35 cases (17.0%)—prolonged air leak was the most common (17 cases). One fatality occurred in an elderly patient with pneumonia and sepsis (0.4%). Comparison of the first 60 patients (learning curve) with subsequent 145 patients (consolidated experience) showed significant differences in surgical and ICU time, both favoring consolidated experience.

Conclusions

Our results were comparable to the literature. Robotic thoracic surgery can be safely and successfully implemented in tertiary hospitals in emerging countries provided that all stakeholders are involved and compromised with the implementation process.
Perioperative Fluid Restriction in Abdominal Surgery: A Systematic Review and Meta‐analysis
Authors: Shen Yanfei , Cai Guolong , Gong Shijin , Yan Jing
Published: July 2019

Background

Perioperative fluid management is a critical component in patients undergoing abdominal surgery. However, the benefit of restricted fluid regimen remains inconclusive. This systematic review aimed to explore potential factors causing these inconsistent findings.

Methods

The literature searches were performed in three databases including PubMed, Embase, and the Cochrane library until August 30, 2018. Only randomized, controlled trials comparing the effect of restricted versus liberal regimen in abdominal surgery were included. The primary outcome was total postoperative complications. Subgroup analysis was performed according to between‐group weight increase difference (≥ 2 kg and < 2 kg) and fluid intake ratio (≥ 1.8 and < 1.8).

Results

Sixteen studies were finally included in this meta‐analysis. The benefit of the restricted regimen in reducing postoperative complication was only significant in the subgroup with high weight increase difference (≥ 2 kg) (RR 0.67, 95% CI 0.57–0.79) and the subgroup with high fluid intake ratio (≥ 1.8) (RR 0.72, 95% CI 0.62–0.82). In the subgroup with low weight increase difference (< 2 kg) or low fluid intake ratio (< 1.8), the effect of the restricted regimen was not significant (RR 0.88, 95% CI 0.51–1.50, and RR 1.18, 95% CI 0.91–1.53, respectively).

Conclusions

The benefit of the restricted regimen was only significant in the subgroup with high weight increase difference (≥ 2 kg) or high fluid intake ratio (≥ 1.8).
Home-based parent training for school-aged children with attention-deficit/hyperactivity disorder and behavior problems with remaining impairing disruptive behaviors after routine treatment: a randomized controlled trial
Authors: Nobel Ellen , Hoekstra Pieter J. , Agnes Brunnekreef J. , Messink-de Vries Dieneke E. H. , Fischer Barbara , Emmelkamp Paul M. G. , van den Hoofdakker Barbara J.
Published: July 2019

The objective is to investigate the effectiveness of home-based behavioral parent training for school-aged children with attention-deficit/hyperactivity disorder (ADHD) and behavior problems with remaining impairing disruptive behaviors after routinely offered treatments in clinical practice. In a randomized controlled study including 73 referred children with ADHD and impairing disruptive symptoms after routine clinical pharmacotherapy and/or clinic-based parent training had been tried or, at least, offered, home-based behavioral parent training (n = 26) was compared to a waiting list (n = 23) and a care-as-usual home-based treatment (n = 24). It was unknown to families which of the home-based treatments that they received. Using mixed models for repeated measures, we examined the effectiveness on the primary outcome measure of children’s severity of disruptive behaviors and on a number of secondary outcome measures [the degree to which parents experienced the disruptive behaviors as troublesome, ADHD symptoms, oppositional-defiant disorder (ODD) symptoms, and internalizing problems]. Compared to the waiting list, children receiving home-based parent training improved significantly more regarding severity of disruptive behaviors (ES = 0.75), ADHD symptoms (ES = 0.89), ODD symptoms (ES = 0.65), and internalizing problems (ES = 0.60). Compared to care-as-usual, home-based parent training was more effective in reducing disruptive behaviors (ES = 0.57), ADHD symptoms (ES = 0.89), and ODD symptoms (ES = 0.88). Significantly more reduction of children’s internalizing problems was not found. In conclusion, children with ADHD and residual behavioral problems after routine treatment may benefit from home-based behavioral parent training.
Impact of polymer addition, electrolyte, clay and antioxidant on rheological properties of polymer fluid at high temperature and high pressure
Authors: Zheng Wenlong , Wu Xiaoming , Huang Yuming
Published: July 2019

Nowadays, the application of polymer in petroleum industries due to its feasibility with enhancing hole cleaning, less formation damage characteristics of drilling fluids has been particularly advantageous in deep well operation. However, figuring out the influence mechanism of temperature on the rheological behavior of polymer fluids and keeping the excellent rheological regulation at high temperature and high pressure (HTHP) are still serious issues for the mud designers. In this work, the rheological properties of a commonly used drilling fluid polymer treating agent named Driscal-D were tested under HTHP conditions by Fann 50SL rheometer. The effects of polymer addition, electrolyte, clay type and antioxidant on the rheological properties of Driscal-D solution were studied in high-temperature environments. Results showed that the viscosity of the solutions tends to increase with the polymer addition increases, making its pseudoplastic characteristics more noticeable. As the temperature rises, the fluid loses viscosity, causing the polymer solution to evolve from pseudoplastic fluid to Newtonian fluid. The presence of the electrolyte and the oxygen scavenger leads to a decrease in the viscosity of the solution, but in high-temperature environments, the solution adding formate or antioxidant has a higher viscosity retention rate than the pure solution at low shear rates (< 50 s−1). The incorporation of the clay in Driscal-D solution enhances the rheological properties, which is beneficial for cuttings transportation. And the dispersion is best described by Herschel–Bulkley model.
New perspectives on the Erlang-A queue
Authors: Daw Andrew , Pender Jamol
Published: July 2019

The nonstationary Erlang-A queue is a fundamental queueing model that is used to describe the dynamic behavior of large-scale multiserver service systems that may experience customer abandonments, such as call centers, hospitals, and urban mobility systems. In this paper we develop novel approximations to all of its transient and steady state moments, the moment generating function, and the cumulant generating function. We also provide precise bounds for the difference of our approximations and the true model. More importantly, we show that our approximations have explicit stochastic representations as shifted Poisson random variables. Moreover, we are also able to show that our approximations and bounds also hold for nonstationary Erlang-B and Erlang-C queueing models under certain stability conditions.