bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and initial validation of a novel smoothed‐particle hydrodynamics‐based simulation model of trabecular bone penetration by metallic implants
Authors: Kulper Sloan A. , Fang Christian X. , Ren Xiaodan , Guo Margaret , Sze Kam Y. , Leung Frankie K. L. , Lu William W.
Published: September 2017

A novel computational model of implant migration in trabecular bone was developed using smoothed‐particle hydrodynamics (SPH), and an initial validation was performed via correlation with experimental data. Six fresh‐frozen human cadaveric specimens measuring 10 × 10 × 20 mm were extracted from the proximal femurs of female donors (mean age of 82 years, range 75–90, BV/TV ratios between 17.88% and 30.49%). These specimens were then penetrated under axial loading to a depth of 10 mm with 5 mm diameter cylindrical indenters bearing either flat or sharp/conical tip designs similar to blunt and self‐tapping cancellous screws, assigned in a random manner. SPH models were constructed based on microCT scans (17.33 µm) of the cadaveric specimens. Two initial specimens were used for calibration of material model parameters. The remaining four specimens were then simulated in silico using identical material model parameters. Peak forces varied between 92.0 and 365.0 N in the experiments, and 115.5–352.2 N in the SPH simulations. The concordance correlation coefficient between experimental and simulated pairs was 0.888, with a 95%CI of 0.8832–0.8926, a Pearson ρ (precision) value of 0.9396, and a bias correction factor Cb (accuracy) value of 0.945. Patterns of bone compaction were qualitatively similar; both experimental and simulated flat‐tipped indenters produced dense regions of compacted material adjacent to the advancing face of the indenter, while sharp‐tipped indenters deposited compacted material along their peripheries. Simulations based on SPH can produce accurate predictions of trabecular bone penetration that are useful for characterizing implant performance under high‐strain loading conditions. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1114–1123, 2018.
Does Lesion Size Affect the Value of Shear Wave Elastography for Differentiating Between Benign and Malignant Thyroid Nodules?
Authors: Wang Fen , Chang Cai , Chen Min , Gao Yi , Chen Ya‐Ling , Zhou Shi‐Chong , Li Jia‐Wei , Zhi Wen‐Xiang
Published: September 2017

Objectives

We aimed to investigate the diagnostic performance of shear wave elastography (SWE) combined with conventional ultrasonography (US) for differentiating between benign and malignant thyroid nodules of different sizes.

Methods

A total of 445 thyroid nodules from 445 patients were divided into 3 groups based on diameter (group 1, ≤ 10 mm; group 2, 10–20 mm; and group 3, > 20 mm). The mean elasticity index of the whole lesion was automatically calculated, and the threshold for differentiation between benign and malignant nodules was constructed by a receiver operating characteristic curve analysis. Diagnostic performances of conventional US and SWE were compared by using pathologic results as reference standards.

Results

The mean elasticity was significantly higher in malignant versus benign nodules for all size groups. The differences in mean elasticity in the size groups were not statistically significant for malignant or benign nodules. The specificity of US combined with SWE for group 1 was significantly higher than that for groups 2 and 3 (77.8% versus 62.9% and 53.3%; P < .05), and compared with group 1, the sensitivity was significantly higher for groups 2 and 3 (92.4% and 94.3% versus 80.7%; P < .05). When SWE was added, the specificity increased and the sensitivity and diagnostic accuracy decreased for group 1, and the sensitivity increased and the specificity decreased for groups 2 and 3; however, the differences were not significant.

Conclusions

Combined with SWE, US yielded higher specificity for nodules of 10 mm and smaller and higher sensitivity for nodules larger than 10 mm.
A new integrable equation that combines the KdV equation with the negative‐order KdV equation
Authors: Wazwaz Abdul‐Majid
Published: September 2017

In this work, we develop a new integrable equation by combining the KdV equation and the negative‐order KdV equation. We use concurrently the KdV recursion operator and the inverse KdV recursion operator to construct this new integrable equation. We show that this equation nicely passes the Painlevé test. As a result, multiple soliton solutions and other soliton and periodic solutions are guaranteed and formally derived.
Steer‐PROP: a GRASE‐PROPELLER sequence with interecho steering gradient pulses
Authors: Srinivasan Girish , Rangwala Novena , Zhou Xiaohong Joe
Published: September 2017

Purpose

This study demonstrates a novel PROPELLER (periodically rotated overlapping parallel lines with enhanced reconstruction) pulse sequence, termed Steer‐PROP, based on gradient and spin echo (GRASE), to reduce the imaging times and address phase errors inherent to GRASE. The study also illustrates the feasibility of using Steer‐PROP as an alternative to single‐shot echo planar imaging (SS‐EPI) to produce distortion‐free diffusion images in all imaging planes.

Methods

Steer‐PROP uses a series of blip gradient pulses to produce N (N = 3‐5) adjacent k‐space blades in each repetition time, where N is the number of gradient echoes in a GRASE sequence. This sampling strategy enables a phase correction algorithm to systematically address the GRASE phase errors as well as the motion‐induced phase inconsistency. Steer‐PROP was evaluated on phantoms and healthy human subjects at both 1.5T and 3.0T for T2‐ and diffusion‐weighted imaging.

Results

Steer‐PROP produced similar image quality as conventional PROPELLER based on fast spin echo (FSE), while taking only a fraction (e.g., 1/3) of the scan time. The robustness against motion in Steer‐PROP was comparable to that of FSE‐based PROPELLER. Using Steer‐PROP, high quality and distortion‐free diffusion images were obtained from human subjects in all imaging planes, demonstrating a considerable advantage over SS‐EPI.

Conclusion

The proposed Steer‐PROP sequence can substantially reduce the scan times compared with FSE‐based PROPELLER while achieving adequate image quality. The novel k‐space sampling strategy in Steer‐PROP not only enables an integrated phase correction method that addresses various sources of phase errors, but also minimizes the echo spacing compared with alternative sampling strategies. Steer‐PROP can also be a viable alternative to SS‐EPI to decrease image distortion in all imaging planes. Magn Reson Med 79:2533–2541, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Simple method for RF pulse measurement using gradient reversal
Authors: Landes Vanessa L. , Nayak Krishna S.
Published: September 2017

Purpose

To develop and evaluate a simple method for measuring the envelope of small‐tip radiofrequency (RF) excitation waveforms in MRI, without extra hardware or synchronization.

Theory and Methods

Gradient reversal approach to evaluate RF (GRATER) involves RF excitation with a constant gradient and reversal of that gradient during signal reception to acquire the time‐reversed version of an RF envelope. An outer‐volume suppression prepulse is used optionally to preselect a uniform volume. GRATER was evaluated in phantom and in vivo experiments. It was compared with the programmed waveform and the traditional pick‐up coil method.

Results

In uniform phantom experiments, pick‐up coil, GRATER, and outer‐volume suppression + GRATER matched the programmed waveforms to less than 2.1%, less than 6.1%, and less than 2.4% normalized root mean square error, respectively, for real RF pulses with flip angle less than or equal to 30°, time‐bandwidth product 2 to 8, and two to five excitation bands. For flip angles greater than 30°, GRATER measurement error increased as predicted by Bloch simulation. Fat‐water phantom and in vivo experiments with outer‐volume suppression + GRATER demonstrated less than 6.4% normalized root mean square error.

Conclusions

The GRATER sequence measures small‐tip RF envelopes without extra hardware or synchronization in just over two times the RF duration. The sequence may be useful in prescan calibration and for measurement and precompensation of RF amplifier nonlinearity. Magn Reson Med 79:2642–2651, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Preemptive parallel‐machine scheduling with a common server to minimize makespan
Authors: Cheng T.C.E. , Kravchenko Svetlana A. , Lin Bertrand M.T.
Published: September 2017

We consider parallel‐machine scheduling with a common server and job preemption to minimize the makespan. While the non‐preemptive version of the problem is strongly NP‐hard, the complexity status of the preemptive version has remained open. We show that the preemptive version is NP‐hard even if there is a fixed number of machines. We give a pseudo‐polynomial time algorithm to solve the case with two machines. We show that the case with an arbitrary number of machines is unary NP‐hard, analyze the performance ratios of some natural heuristic algorithms, and present several solvable special cases. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 388–398, 2017
Improving mechanical, thermal, and electrical properties of polyimide by incorporating vinyltriethoxysilane functionalized graphene oxide
Authors: Fazil Srosh , Saeed Shaukat , Waseem Muhammad , Rehman Wajid , Bangesh Masroor , Liaqat Khurram
Published: September 2017

Functionalized graphene oxide (FGO) nanosheets were produced by reacting graphene oxide with vinyltriethoxysilane (VTES). The vinyltriethoxysilane graphene oxide and polyimide (VGO/PI) composites were prepared by solution blending method. In comparison with the pristine polyimide (PI) and graphene oxide/polyimide (GO/PI) composite, VGO showed better mechanical, electrical and thermal properties. The tensile strength of VGO/PI composite with 0.8 wt% VGO loading was up to 148 MPa, i.e., 105% higher than that of pure PI. The respective electrical and thermal conductivity values of composite were found 2.15 × 10−3 S/m and 0.89 W/mK as compared to 1.21 × 10−12 S/m and 0.13 W/mK for the pure PI. The thermal stability of composite was found to improve with the addition of VGO. Significant improvement in the properties has been explained in terms of homogeneous dispersion of VGO in the matrix and its strong interfacial adhesion with polymer due to surface modification of GO. POLYM. COMPOS., 39:E1635–E1642, 2018. © 2017 Society of Plastics Engineers
Research to support optimization of prescription drug monitoring programs
Authors: Doyle Sheri , Leichtling Gillian , Hildebran Christi , Reilly Cynthia
Published: September 2017

Purpose

Research is needed to evaluate the impact of prescription drug monitoring programs (PDMPs). This paper describes research priorities for PDMPs that were initially discussed at a 2015 meeting of PDMP administrators, researchers, public health officials, and other stakeholders.

Methods

Meeting participants defined the current landscape of PDMP research and identified research gaps. Research priorities were grouped by theme.

Results

Prescription drug monitoring program research priorities were identified for 3 key areas: individual patient health outcomes, prescriber use and decision making, and population‐level outcomes. Research areas for individual patient outcomes include examining drug‐use thresholds that best predict risk for overdose or substance use disorder and unintended consequences of PDMP use. Proposed research on prescriber PDMP use include evaluating how enhancements to the content and format of PDMP reports informs clinical decision making and optimal clinician actions in response to a concerning PDMP report. Finally, research topics related to population‐level outcomes include measuring the impact of PDMP policies on the incidence of substance misuse and harms and assessing the return on investment for these databases.

Conclusions

The clinical, public health, and economic impacts of PDMPs must be evaluated, using both quantitative and qualitative methods. In addition to assessing patient outcomes, qualitative research should examine how clinicians use and interpret PDMP information. Research should also examine the impact of PDMP features and policies on prescriber utilization. Comparative analyses across states with differing PDMP policies should be conducted to inform best practices.
Isatin‐induced increase in the affinity of human ferrochelatase and adrenodoxin reductase interaction
Authors: Ershov Pavel , Mezentsev Yuri , Gilep Andrey , Usanov Sergey , Buneeva Olga , Medvedev Alexei , Ivanov Alexis
Published: September 2017

Isatin (indol‐2,3‐dione) is an endogenous non‐peptide regulator exhibiting a wide range of biological and pharmacological activities, which are poorly characterized in terms of their molecular mechanisms. Identification of many isatin‐binding proteins in the mammalian brain and liver suggests that isatin may influence their functions. We have hypothesized that besides direct action on particular protein targets, isatin can act as a regulator of protein–protein interactions (PPIs). In this surface plasmon resonance‐based biosensor study we have found that physiologically relevant concentrations of isatin (25‐100 μM) increase affinity of interactions between human recombinant ferrochelatase (FECH) and NADPH‐dependent adrenodoxin reductase (ADR). In the presence of increasing concentrations of isatin the Kd values demonstrated a significant (up to 6‐fold) decrease. It is especially important that the interaction of isatin with each individual protein (FECH, ADR) was basically negligible and therefore could not contribute to the observed effect. This effect was specific only for the FECH/ADR complex formation and was not observed for other protein complexes studied: FECH/cytochrome b5(CYB5A) and FECH/SMAD4.
Somatostatin receptor subtype 1 as a potential diagnostic marker and therapeutic target in prostate cancer
Authors: Pedraza‐Arévalo Sergio , Hormaechea‐Agulla Daniel , Gómez‐Gómez Enrique , Requena María J. , Selth Luke A. , Gahete Manuel D. , Castaño Justo P. , Luque Raul M.
Published: September 2017

Background

Prostate cancer (PCa) is a highly prevalent neoplasia that is strongly influenced by the endocrine system. Somatostatin (SST) and its five receptors (sst1‐5 encoded by SSTR1‐5 genes) comprise a pleiotropic system present in most endocrine‐related cancers, some of which are successfully treated with SST analogs. Interestingly, it has been reported that SSTR1 is overexpressed in PCa, but its regulation, functional role, and clinical implications are still poorly known.

Methods

PCa specimens (n = 52) from biopsies and control prostates from cystoprostatectomies (n = 12), as well as in silico databases were used to evaluate SSTR1 and miRNAs expression. In vitro studies in 22Rv1 PCa cells were implemented to explore the regulation of SSTR1/sst1 by different miRNAs, and to evaluate the consequences of SSTR1/sst1 overexpression, silencing and/or activation [with the specific BIM‐23926 sst1 agonist (IPSEN)] on cell‐proliferation, migration, signaling‐pathways, and androgen‐signaling.

Results

We found that SSTR1 is overexpressed in multiple cohorts of PCa samples, as compared with normal prostate tissues, wherein it correlates with androgen receptor (AR) expression, and appears to be associated with aggressiveness (metastasis). Furthermore, our data revealed that SSTR1/sst1 expression might be regulated by specific miRNAs in PCa, including miR‐24, which is downregulated in PCa samples and correlates inversely with SSTR1 expression. In vitro studies indicated that treatment with the BIM‐23926 sst1 agonist, as well as SSTR1 overexpression, decreased, whereas SSTR1 silencing increased, cell‐proliferation in 22Rv1 cells, likely through the regulation of PI3K/AKT‐CCND3 signaling‐pathway. Importantly, sst1 action was also able to modulate androgen/AR activity, and reduced PSA secretion from PCa cell lines.

Conclusions

Altogether, our results indicate that SSTR1 is overexpressed in PCa, where it can exert a relevant pathophysiological role by decreasing cell‐proliferation and PSA secretion. Therefore, sst1, possibly in combination with miR‐24, could be used as a novel tool to explore therapeutic targets in PCa.
Modeling of protein complexes in CAPRI Round 37 using template‐based approach combined with model selection
Authors: Dapkūnas Justas , Olechnovič Kliment , Venclovas Česlovas
Published: September 2017

We participated in Round 37 of the Critical Assessment of PRediction of Interactions (CAPRI), held jointly with the 12th edition of the Critical Assessment of protein Structure Prediction (CASP12), having two major objectives. First, we intended to test the utility of our PPI3D web server in finding and selecting templates for comparative modeling of structures of protein complexes. Our second aim was to evaluate the ability of our model accuracy estimation method VoroMQA to score and rank structural models for protein‐protein interactions. Using sequence search in PPI3D and HHpred servers we identified multimeric templates for 7 of 11 CAPRI targets, and models of at least acceptable quality were constructed for 6 of them. The clustering and visual analysis features implemented in the PPI3D software were instrumental in detecting alternative protein‐protein interaction interfaces among the identified templates. When a single binding mode was observed for homologous proteins, the structural modeling of the protein complex was fairly straightforward, whereas choosing the correct interaction template from several alternatives turned out to be a difficult task requiring manual intervention. The combination of full structure and interaction interface VoroMQA scores effectively ranked structural models of protein complexes and selected models of better quality from the CAPRI Scoring sets. The overall results show possible uses of PPI3D and VoroMQA in structural modeling of protein‐protein interactions and suggest ways for further improvements of both methods.
Anion induced conformational preference of CαNN motif residues in functional proteins
Authors: Patra Piya , Ghosh Mahua , Banerjee Raja , Chakrabarti Jaydeb
Published: September 2017

Among different ligand binding motifs, anion binding CαNN motif consisting of peptide backbone atoms of three consecutive residues are observed to be important for recognition of free anions, like sulphate or biphosphate and participate in different key functions. Here we study the interaction of sulphate and biphosphate with CαNN motif present in different proteins. Instead of total protein, a peptide fragment has been studied keeping CαNN motif flanked in between other residues. We use classical force field based molecular dynamics simulations to understand the stability of this motif. Our data indicate fluctuations in conformational preferences of the motif residues in absence of the anion. The anion gives stability to one of these conformations. However, the anion induced conformational preferences are highly sequence dependent and specific to the type of anion. In particular, the polar residues are more favourable compared to the other residues for recognising the anion.
Investigating the structural dynamics of the PIEZO1 channel activation and inactivation by coarse‐grained modeling
Authors: Zheng Wenjun , Sachs Frederick
Published: September 2017

The PIEZO channels, a family of mechanosensitive channels in vertebrates, feature a fast activation by mechanical stimuli (eg, membrane tension) followed by a slower inactivation. Although a medium‐resolution structure of the trimeric form of PIEZO1 was solved by cryo‐electron microscopy (cryo‐EM), key structural changes responsible for the channel activation and inactivation are still unknown. Toward decrypting the structural mechanism of the PIEZO1 activation and inactivation, we performed systematic coarse‐grained modeling using an elastic network model and related modeling/analysis tools (ie, normal mode analysis, flexibility and hotspot analysis, correlation analysis, and cryo‐EM‐based hybrid modeling and flexible fitting). We identified four key motional modes that may drive the tension‐induced activation and inactivation, with fast and slow relaxation time, respectively. These modes allosterically couple the lateral and vertical motions of the peripheral domains to the opening and closing of the intra‐cellular vestibule, enabling external mechanical forces to trigger, and regulate the activation/inactivation transitions. We also calculated domain‐specific flexibility profiles, and predicted hotspot residues at key domain‐domain interfaces and hinges. Our results offer unprecedented structural and dynamic information, which is consistent with the literature on mutational and functional studies of the PIEZO channels, and will guide future studies of this important family of mechanosensitive channels.
Adaptive dynamic surface asymptotic tracking for a class of uncertain nonlinear systems
Authors: Liu Yong‐Hua
Published: September 2017

This paper contributes to dynamic surface asymptotic tracking for a class of uncertain nonlinear systems in strict‐feedback form. By utilizing the nonlinear filters with a positive time‐varying integral function, an adaptive state feedback controller is explicitly designed via a dynamic surface approach, where the compensating term with the estimate of an unknown bound is introduced to eliminate the effect raised by the boundary layer error at each step. Compared with the existing results in the literature, the proposed control scheme not only avoids the issue of “explosion of complexity” inherent in the backstepping procedure but also holds the asymptotic output tracking. Finally, simulation results are presented to verify the effectiveness of the proposed methodology.
Hydrostatic versus nonhydrostatic hydrodynamic modelling of secondary flow in a tortuously meandering river: Application of Delft3D
Authors: Parsapour‐Moghaddam P. , Rennie C.D.
Published: September 2017

Given the importance of pressure gradients in driving secondary flow, it is worth studying how the modelled flow structures in a natural river bend can be impacted by the assumption of hydrodynamic pressure. In this paper, the performance of hydrostatic versus nonhydrostatic pressure assumption in the three‐dimensional (3D) hydrodynamic modelling of a tortuously meandering river is studied. Both hydrostatic and nonhydrostatic numerical models were developed using Delft3D‐Flow to predict the 3D flow field in a reach of Stillwater Creek in Ottawa, Canada. An acoustic Doppler velocimeter was employed to measure the 3D flow field at a section in a sharp bend of the simulated river at two flow stages. The results of the Delft3D hydrostatic model agreed well with the acoustic Doppler velocimeter measurements: The hydrostatic model predicted reasonably accurately both the streamwise velocity distribution across the section and the magnitude and location of the primary secondary flow cell. The results of the Delft3D nonhydrostatic approximation showed that the model was not conservative and could not accurately generate either the secondary flow or the streamwise velocity distribution. This study illustrated the superior performance of the hydrostatic over nonhydrostatic 3D modelling of the secondary flow using Delft3D. Several possible reasons for unfavourable performance of the nonhydrostatic version of Delft3D are discussed, including the pressure correction technique employed in Delft3D. Considering the uncertainties that may arise in both modelling and field measurements, the 3D hydrostatic Delft3D model was capable of reasonably predicting the river bend flow structures in the studied meandering creek.
The decline of science in corporate R&D
Authors: Arora Ashish , Belenzon Sharon , Patacconi Andrea
Published: September 2017

Research summary: In this article, we document a shift away from science by large corporations between 1980 and 2006. We find that publications by company scientists have declined over time in a range of industries. We also find that the value attributable to scientific research has dropped, whereas the value attributable to technical knowledge (as measured by patents) has remained stable. These trends are unlikely to be driven principally by changes in publication practices. Furthermore, science continues to be useful as an input into innovation. Our evidence points to a reduction of the private benefits of internal research. Large firms still value the golden eggs of science (as reflected in patents), but seem to be increasingly unwilling to invest in the golden goose itself (the internal scientific capabilities).

Managerial summary: There is a widespread belief among commentators that large American corporations are withdrawing from research. Large corporations may still collaborate with universities and acquire promising science‐based start‐ups, but their labs increasingly focus on developing existing knowledge and commercializing it, rather than creating new knowledge. In this article, we combine firm‐level financial information with a large and comprehensive data set on firm publications, patents and acquisitions to quantify the withdrawal from science by large American corporations between 1980 and 2006. This withdrawal is associated with a decline in the private value of research activities, even though scientific knowledge itself remains important for corporate invention. We discuss the managerial and policy implications of our findings.
Do ongoing networks block out new friends?Reconciling the embeddedness constraint dilemma on new alliance partner addition
Authors: Jiang Han , Xia Jun , Cannella Albert A. , Xiao Ting
Published: September 2017

Research Summary:This study addresses a theoretical dilemma regarding how alliance network constraint (reflected by network cohesion) affects a firm’s alliance formation with new partners. Using a network pluralism approach, we separate a firm’s ego alliance network into two activity‐based networks—an exploratory network and an exploitative network—based on the primary value chain activity involved in each alliance. We argue that the cohesion of exploratory or exploitative networks has an inverted U‐shaped effect on the addition of new partners in the same activity‐based network, and a positive effect on the addition of new partners in the other network. Results based on data from the biotechnology industry largely support our predictions with one exception. Our study contributes to both scholarly understanding of network embeddedness and alliance practice.

Managerial Summary:The structure of firms’ ongoing alliance networks may have paradoxical implications for their efforts to search for and form alliance with new partners. That is, when a firm’s alliance partners are tightly connected with each other, the cohesive network tends to both encourage and impede the focal firm to add new partners. We resolve this dilemma by showing that when a firm is deeply entrenched in a cohesive alliance network conducting a certain type of activities (e.g., R&D activities), it may not easily add new R&D alliance partners. However, it may still be able to escape from the cohesive R&D alliance network by seeking new partners conducting other activities (e.g., manufacturing activities).
BS in the boardroom: Benevolent sexism and board chair orientations
Authors: Oliver Abbie G. , Krause Ryan , Busenbark John R. , Kalm Matias
Published: September 2017

Research Summary: Though research has focused on the ascent and acceptance of female CEOs, the post‐promotion circumstances female CEOs face remain unclear. In this study, we focus on a critical post‐promotion circumstance: the board chair–CEO relationship. Drawing on the gender stereotype literature, agency theory, and stewardship theory, we posit that firms appointing a female CEO are more likely to adopt a collaboration board chair orientation and less likely to adopt a control orientation. We further predict this effect is attenuated by female board representation. Using a sample of new S&P 1500 CEOs, we find support for our predictions regarding the collaboration orientation but not the control orientation. This research provides some evidence of benevolent sexism in the boardroom, with female directors acting as a countervailing influence.

Managerial Summary: Whereas the notion that females encounter a glass ceiling on their path toward CEO is well documented, the conditions female CEOs encounter after promotion are less understood. The relationship between the board chair and the CEO is one important post‐promotion condition. Board chairs can focus on monitoring and/or working together with the CEO. We suggest board chairs are more likely to work in close collaboration with female CEOs than with male CEOs. We attribute this to benevolent sexism, which explains that board chairs are more likely to collaborate with female CEOs because they view females as more conducive to, and in need of, this type of relationship. We also suggest this benevolent sexism is less prevalent when there are more females on the board.
Virtuous or vicious cycles? The role of divestitures as a complementary Penrose effect within resource‐based theory
Authors: Vidal Elena , Mitchell Will
Published: September 2017

Research summary: Studies of how divestitures affect firm performance offer mixed results. This paper unpacks relationships between divestitures and subsequent performance, focusing first on the moderating role of prior performance and then on mechanisms through which divestitures by higher‐ and lower‐performing firms affect performance. The study suggests that divestitures can exacerbate weakness and reinforce strength: divestitures by lower performers improve profits but inhibit sales growth and tend to speed the firms’ exits as independent actors; by contrast, higher‐performing divesters invest in support of existing assets and gain new growth, while avoiding becoming acquisition targets. Most generally, divestitures help reduce constraints to changing a firm's resource base, which we refer to as a complementary Penrose effect.

Managerial summary: Divestitures help both struggling firms and high performers free financial and managerial resources that they can reinvest in more productive uses. In doing so, divestitures reinforce the strength of high performers but may exacerbate weaknesses of struggling firms. Divestitures by lower performers improve their profits but inhibit their sales growth and increase the chances that the firms will be acquired. By contrast, higher‐performing divesters gain new growth by investing in support of existing and recently acquired assets and, by doing so, are less likely to become targets of acquirers who seek their productive assets. Thus, divestiture is part of a downward cycle for struggling firms but supports a virtuous cycle for superior firms.
Context‐based approach to prioritize code smells for prefactoring
Authors: Sae‐Lim Natthawute , Hayashi Shinpei , Saeki Motoshi
Published: September 2017

Existing techniques for detecting code smells (indicators of source code problems) do not consider the current context, which renders them unsuitable for developers who have a specific context, such as modules within their focus. Consequently, the developers must spend time identifying relevant smells. We propose a technique to prioritize code smells using the developers' context. Explicit data of the context are obtained using a list of issues extracted from an issue tracking system. We applied impact analysis to the list of issues and used the results to specify the context‐relevant smells. Results show that our approach can provide developers with a list of prioritized code smells related to their current context. We conducted several empirical studies to investigate the characteristics of our technique and factors that might affect the ranking quality. Additionally, we conducted a controlled experiment with professional developers to evaluate our technique. The results demonstrate the effectiveness of our technique.
Highly Efficient and Stable Planar Perovskite Solar Cells With Large‐Scale Manufacture of E‐Beam Evaporated SnO2 Toward Commercialization
Authors: Ma Junjie , Zheng Xiaolu , Lei Hongwei , Ke Weijun , Chen Cong , Chen Zhiliang , Yang Guang , Fang Guojia
Published: September 2017

In recent years, photovoltaic properties of hybrid perovskite solar cells (PSCs) have led to impressive improvement. Yet, there is still remain a challenge for large scale application and commercialization. Some of the reasons are the instability of the perovskite film and the lack of large‐scale and low‐cost manufacture techniques for electron transport layer (ETL). Tin oxide (SnO2) has emerged as a promising candidate for ETL, however, systematic exploration of its commercialized application in PSCs is still missing. Here, SnO2 ETL is prepared through an electron beam evaporation technology under low‐temperature process to realize large‐scale, low‐cost, and uniform manufacture. Hundreds of SnO2 ETL substrates can be fabricated at one time, which deserves industrial deployment. As a result, PSCs based on e‐beam evaporated SnO2 ETL and Cs‐containing blended perovskite absorber layer exhibit a power conversion efficiency (PCE) of up to 18.2% without any interface modification. Furthermore, the PSCs demonstrate remarkable long‐term stability, which remained at 97% of its initial PCE after being stored for over 34 days. The results demonstrate the great potential of the PSCs based on e‐beam evaporated SnO2 ETLs towards commercialization.
Clinicopathological Risk Factors for Distant Metastasis in Differentiated Thyroid Carcinoma: A Meta‐analysis
Authors: Vuong Huy Gia , Duong Uyen N. P. , Pham Thong Quang , Tran Hung Minh , Oishi Naoki , Mochizuki Kunio , Nakazawa Tadao , Hassell Lewis , Katoh Ryohei , Kondo Tetsuo
Published: September 2017

Introduction

Distant metastasis (DM) is not a frequent event in differentiated thyroid carcinoma (DTC) but has an adverse impact on mortality of patients with DTC. In the current study, we aimed to conduct a comprehensive systematic review and meta‐analysis to investigate the risk factors for DM in DTCs and for each histological subtype.

Methods

Five electronic databases were searched from inception to December 2016 for relevant articles. Pooled odd ratios and 95% confidence interval were calculated using random‐effect model.

Results

Thirty‐four articles with 73,219 patients were included for meta‐analyses. In DTCs, male gender, age ≥45 years, tumor size ≥4 cm, multifocality, vascular invasion (VI), extrathyroidal extension (ETE), lymph node metastasis (LNM), and lateral LNM were demonstrated to be associated with significant risks for DM. In addition, several clinicopathological factors such as age ≥45 years, VI, ETE, and LNM were shown to be significant risk factors for DM in both PTC and FTC subgroups.

Conclusion

Our study demonstrated the promising value of several clinicopathological factors such as male gender, older age, VI, ETE, and LNM in predicting DM in PTCs and FTCs. Our study affirms the value of the selected clinicopathological factors for tumor risk stratification and assessment of patients’ prognosis.
Case report and literature review: Management of squamous cell carcinoma in situ of the nipple
Authors: Bowers Anne , Monteverde Alexandra , Heimann Alan , Kapenhas Edna , Notaro Antoinette
Published: September 2017

Highlights
Atherosclerotic Disease and its Relationship to Lumbar Degenerative Disk Disease, Facet Arthritis, and Stenosis With Computed Tomography Angiography
Authors: Beckworth William J. , Holbrook John F. , Foster Lisa G. , Ward Laura A. , Welle James R.
Published: September 2017

Background

The intervertebral disk is the largest avascular structure in the body. It relies on passive diffusion from arteries at the periphery of the disk for nutrition. Previous studies have suggested a correlation between vascular disease and lumbar degenerative disk disease (DDD), but the association with facet arthritis and stenosis has not been evaluated.

Objective

To evaluate the degree of lumbar artery stenosis, aortic atherosclerosis on computed tomography angiography, and its relationship to lumbar DDD, facet arthritis, and spinal canal stenosis.

Design

Retrospective case review.

Setting

Academic tertiary care hospital.

Participants

Not applicable.

Methods

A total of 300 lumbar arteries (150 lumbar artery pairs of the first to fifth lumbar arteries) were evaluated on consecutive computed tomography angiography scans. Severity of vascular disease of lumbar arteries was documented as normal, mild, moderate, severe, or occluded. Aortic vascular disease was documented along the posterior wall where the lumbar arteries originate.

Main Outcome Measurements

The relationship between vascular disease with DDD, facet arthritis, and spinal canal stenosis was examined and further evaluated controlling for age.

Results

Lumbar artery and aortic atherosclerosis had a positive relationship with DDD, facet arthritis, and spinal stenosis that was statistically significant (P < .05) even after controlling for age. The correlation coefficient was greatest in the younger age group when looking at lumbar artery vascular disease with DDD (0.73, confidence interval 0.50‐0.96, P < .0001) and aortic vascular disease with DDD (0.72, confidence interval 0.49‐0.94, P < .0001). The correlation of vascular disease with facet arthritis and stenosis was not strong in the older age group.

Conclusion

Atherosclerotic disease of the lumbar arteries and aorta correlated with lumbar DDD, facet arthritis, and spinal canal stenosis after we adjusted for age, although the correlation with facet arthritis and spinal canal stenosis was not as strong in the older age group.

Level of Evidence

IV
Therapeutically Supporting Children to Recover from the Impact of Family Violence
Authors: Powell Olivia , Morrison Kathy
Published: September 2017

Family violence (also referred to as Domestic Violence and Intimate Partner Violence) describes violence that occurs within an intimate relationship, whether a current or former partner. Children can experience a range of abuses (emotional, physical, sexual and neglect) within the context of family violence, and harm is cumulative and may present as complex trauma. This paper is based on a practice presentation delivered at the International Childhood Trauma Conference in Melbourne (Australia) in June 2016. The purpose of this paper is to increase awareness of the impacts for children who have experienced family violence, to enhance understanding of the mechanisms that contribute to their trauma presentation, and to highlight the specific practice issues and considerations in providing therapeutic support to this client population, with the ultimate aim of improving diagnostic and treatment outcomes for children impacted by family violence. Sufficient safety and stability are required for children to experience therapeutic change, and if family violence is current, the initial response needs to be protective. Identification of family violence should prompt practitioners to use trauma-informed assessment and trauma-focused evidence-based treatments within a family therapy and systems framework. Family violence is complex and there are many barriers to treatment and practice considerations. Expansion of practitioner knowledge and skills in family violence trauma will enhance outcomes for children who have experienced family violence.
Rapid Triage of Mental Health Risk in Emergency Medical Workers: Findings From Typhoon Haiyan
Authors: Sylwanowicz Lauren , Schreiber Merritt , Anderson Craig , Gundran Carlos Primero D. , Santamaria Emelie , Lopez Jaifred Christian F.
Published: September 2017

Objective

To determine the ability of a novel responder mental health self-triage system to predict post-traumatic stress disorder (PTSD) in emergency medical responders after a disaster.

Methods

Participants in this study responded to Typhoon Haiyan, which struck the Philippines in November 2013. They completed the Psychological Simple Triage and Rapid Treatment (PsySTART) responder triage tool, the PTSD Checklist (PCL-5) and the Patient Health Questionnaire-8 (PHQ-8) shortly after responding to this disaster. The relationships between these 3 tools were compared to determine the association between different risk exposures while providing disaster medical care and subsequent levels of PTSD or depression.

Results

The total number of PsySTART responder risk factors was closely related to PCL-5 scores ≥38, the threshold for clinical PTSD. Several of the PsySTART risk factors were predictive of clinical levels of PTSD as measured by the PCL-5 in this sample of deployed emergency medical responders.

Conclusions

The presence of a critical number and type of PsySTART responder self-triage risk factors predicted clinical levels of PTSD and subclinical depression in this sample of emergency medical workers. The ability to identify these disorders early can help categorize an at-risk subset for further timely “stepped care” interventions with the goals of both mitigating the long-term consequences and maximizing the return to resilience. (Disaster Med Public Health Preparedness. 2018;12:19–22)
Can National Healthcare-Associated Infections (HAIs) Data Differentiate Hospitals in the United States?
Authors: Masnick Max , Morgan Daniel J. , Sorkin John D. , Macek Mark D. , Brown Jessica P. , Rheingans Penny , Harris Anthony D.
Published: September 2017

OBJECTIVE

To determine whether patients using the Centers for Medicare and Medicaid Services (CMS) Hospital Compare website (http://medicare.gov/hospitalcompare) can use nationally reported healthcare-associated infection (HAI) data to differentiate hospitals.

DESIGN

Secondary analysis of publicly available HAI data for calendar year 2013.

METHODS

We assessed the availability of HAI data for geographically proximate hospitals (ie, hospitals within the same referral region) and then analyzed these data to determine whether they are useful to differentiate hospitals. We assessed data for the 6 HAIs reported by hospitals to the Centers for Disease Control and Prevention (CDC).

RESULTS

Data were analyzed for 4,561 hospitals representing 88% of registered community and federal government hospitals in the United States. Healthcare-associated infection data are only useful for comparing hospitals if they are available for multiple hospitals within a geographic region. We found that data availability differed by HAI.Clostridium difficileinfections (CDI) data were most available, with 82% of geographic regions (ie, hospital referral regions) having >50% of hospitals reporting them. In contrast, 4% of geographic regions had >50% of member hospitals reporting surgical site infections (SSI) for hysterectomies, which had the lowest availability. The ability of HAI data to differentiate hospitals differed by HAI: 72% of hospital referral regions had at least 1 pair of hospitals with statistically different risk-adjusted CDI rates (SIRs), compared to 9% for SSI (hysterectomy).

CONCLUSIONS

HAI data generally are reported by enough hospitals to meet minimal criteria for useful comparisons in many geographic locations, though this varies by type of HAI. CDI and catheter-associated urinary tract infection (CAUTI) are more likely to differentiate hospitals than the other publicly reported HAIs.

Infect Control Hosp Epidemiol2017;38:1167–1171
Control of viscous instability by variation of injection rate in a fluid with time-dependent rheology
Authors: Beeson-Jones Tim H. , Woods Andrew W.
Published: September 2017

Using variational calculus, we investigate the time-dependent injection rate that minimises the growth of the Saffman–Taylor instability when a finite volume of fluid is injected in a finite time, $t_{f}$, into a Hele-Shaw cell. We first consider a planar interface, and show that, with a constant viscosity ratio, the constant injection rate is optimal. When the viscosity of the displacing fluid, $\unicode[STIX]{x1D707}_{1}(t)$, gradually increases over time, as may occur with a slowly gelling polymer solution, the optimal injection rate, $U^{\ast }(t)$, involves a gradual increase in the flow rate with time. This leads to a smaller initial value of flow rate than the constant injection rate, finishing with a larger value. Such optimisation can lead to a substantial suppression of the instability as compared to the constant injection case if the characteristic gelling time is comparable to $t_{f}$. In contrast, for either relatively slow or fast gelling, there is much less benefit in selecting the optimal injection rate, $U^{\ast }(t)$, as compared to the constant injection rate. In the case of a constant injection rate from a point source, $Q$, then with a constant viscosity ratio the fastest-growing perturbation on the radially spreading front involves axisymmetric modes whose wavenumber increases with time. Approximating the discrete azimuthal modes by a continuous distribution, we find the injection rate that minimises growth, $Q^{\ast }(t)$. We find that there is a critical time for injection, $t_{f}^{\dagger }$, such that if $t_{f}>t_{f}^{\dagger }$ then $Q^{\ast }(t)$ can be chosen so that the interface is always stable. This critical time emerges from the case with an injection rate given by $Q^{\ast }\sim t^{-1/3}$. As the total injection time is reduced to values $t_{f}<t_{f}^{\dagger }$, the system becomes progressively more unstable, and the optimal injection rate for an idealised continuous distribution of azimuthal modes asymptotes to a flow rate that increases linearly with time. As for the one-dimensional case, if the viscosity of the injection fluid gradually increases over time, then the optimal injection rate has a smaller initial value but gradually increases to larger values than for the analogous constant viscosity problem. If the displacing fluid features shear-thinning rheology, then the optimal injection rate involves a smaller flow rate at early times, although not as large a reduction as in the Newtonian case, and a larger flow rate at late times, although not as large an increase as in the Newtonian case.
Generation Mechanism and Reduction Method of Induced Drag Produced by Interacting Wingtip Vortex System
Authors: Zhang M. , Wang Y. K. , Fu S.
Published: September 2017

The formation and evolution of wingtip vortex system generated from three wing configurations are simulated with the improved delayed detached eddy simulation (IDDES) method. Numerical results show that each layout produces an interacting wingtip vortex system. These three corresponding vortical interactions are, respectively, the interaction between wingtip vortex and its counter-rotating vortex, winglet-tip vortex, and winglet four-vortex system. The fluid entrainment of ambient fluid and vortical impulse transport resulted from inductive effect have been founded generally existing in its formation and evolution. These two dominated mechanisms account for induced drag generation. On one hand, the winglet with toed-out angle is considered capable of changing the flow field around the winglet, and decomposing the winglet-tip vortex into four small vortices. Due to quite few fluid entrainment effects, this typical four-vortex system that cannot merge and only dissipate in the near wake scarcely contributes to the induced drag. On the other hand, a potential drag reduction method is also indicated that a lower induced drag can be obtained when the merger of wingtip and winglet-tip vortex is controlled and eliminated. This investigation will offer a novel perspective to guide the design of wingtip device and method of crusing resistance reduction for aircrafts.