bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling mechanical properties of polyhydroxyalkanoate during degradation in animal tissue
Authors: Kehail Abdulrahman A. , Rabbi M d.Fazlay , Bach Nicholas , Chalivendra Vijaya , Brigham Christopher
Published: May 2017

Polyhydroxyalkanoates (PHAs) are a family of biodegradable and biocompatible polymers produced by several species microorganisms that possess favorable mechanical properties (e.g. strength and elongation properties). Different types of PHA polymers have been used in medical applications. However, in order to better understand the use of this polymer in the different applications, a thorough understanding of the kinetics of in vivo degradation is one of the major requirements. In this study, poly(3‐hydroxybutyrate) (PHB) was subcutaneously implanted in mice and incubated for 2, 4, 8, or 16 weeks. After removal from the animal, the strength, elongation, mass loss, and enthalpy of the PHB were tested for each time point. From these data, a mathematical model was generated by Rayleigh's method of dimensional analysis, where polymer strength over tissue contact time could be predicted. To prove the model, previous data obtained by our group were used: poly(3‐hydroxybutyrate‐co‐3‐hydroxyhexanoate) [P(HB‐co‐HHx)] incubation in the presence of human embryonic kidney cells (HEK). It was found that the developed model was aligned with experimental results, could predict the strength of the polymer when in contact with cells, and the predicted strength follows the trend of the experimental data. Also, the dimensionless constant (K) value associated with the model is different for both experiments, where this constant, produced via experimental data, is used for construction of a homogeneous equation. Copyright © 2017 John Wiley & Sons, Ltd.
Preparation of macroporous hydrophobic materials filled with aligned porous hydrophilic domain via emulsion‐templated and unidirectional freezing technique
Authors: Zhu Yun , Lu Zhen , Chen Jianding , Zhang Shengmiao
Published: May 2017

A new class of porous materials, having hydrophobic scaffold embedded with aligned porous hydrophilic domains, was in situ fabricated through combination of emulsion‐templated method and unidirectional freezing technique. A water‐in‐oil high internal phase emulsion (HIPE) was prepared with the mixture of styrene and divinylbenzene as continuous phase and a poly(vinyl alcohol) (PVA) aqueous solution as dispersed phase. After polymerization of the continuous phase and subsequently unidirectional freezing, the dispersed phase, a macroporous poly(styrene/divinylbenzene) embedded with an aligned PVA domain, was obtained. The effects of the polymerization temperature, PVA concentration, and freezing rate on these porous materials were investigated. It was found that the PVA domain size and the aligned channel size were dependent on the polymerization temperature, the PVA concentration, and freezing rate. The fabrication method in this work, combining of unidirectional freezing and emulsion template, not only allows to prepare hydrophobic–hydrophilic polyHIPEs having a sea island structure but also dramatically improves the stiffness and specific surface area of the resulting polyHIPEs. Copyright © 2017 John Wiley & Sons, Ltd.
A pediatric trial of radiation/cetuximab followed by irinotecan/cetuximab in newly diagnosed diffuse pontine gliomas and high‐grade astrocytomas: A Pediatric Oncology Experimental Therapeutics Investigators' Consortium study
Authors: Macy Margaret E. , Kieran Mark W. , Chi Susan N. , Cohen Kenneth J. , MacDonald Tobey J. , Smith Amy A. , Etzl Michael M. , Kuei Michele C. , Donson Andrew M. , Gore Lia , DiRenzo Jennifer , Trippett Tanya M. , Ostrovnaya Irina , Narendran Aru , Foreman Nicholas K. , Dunkel Ira J.
Published: May 2017

Background

Diffuse intrinsic pontine gliomas (DIPGs) and high‐grade astrocytomas (HGA) continue to have dismal prognoses. The combination of cetuximab and irinotecan was demonstrated to be safe and tolerable in a previous pediatric phase 1 combination study. We developed this phase 2 trial to investigate the safety and efficacy of cetuximab given with radiation therapy followed by adjuvant cetuximab and irinotecan.

Methods

Eligible patients of age 3–21 years had newly diagnosed DIPG or HGA. Patients received radiation therapy (5,940 cGy) with concurrent cetuximab. Following radiation, patients received cetuximab weekly and irinotecan daily for 5 days per week for 2 weeks every 21 days for 30 weeks. Correlative studies were performed. The regimen was considered to be promising if the number of patients with 1‐year progression‐free survival (PFS) for DIPG and HGA was at least six of 25 and 14 of 26, respectively.

Results

Forty‐five evaluable patients were enrolled (25 DIPG and 20 HGA). Six patients with DIPG and five with HGA were progression free at 1 year from the start of therapy with 1‐year PFS of 29.6% and 18%, respectively. Fatigue, gastrointestinal complaints, electrolyte abnormalities, and rash were the most common adverse events and generally of grade 1 and 2. Increased epidermal growth factor receptor copy number but no K‐ras mutations were identified in available samples.

Conclusions

The trial did not meet the predetermined endpoint to deem this regimen successful for HGA. While the trial met the predetermined endpoint for DIPG, overall survival was not markedly improved from historical controls, therefore does not merit further study in this population.
The use of antifibrinolytics in pediatric patients with hypoproliferative thrombocytopenia
Authors: Delaney Meghan , Matthews Dana C. , Gernsheimer Terry B.
Published: May 2017

Despite the use of evidence‐based platelet transfusion therapy during periods of hypoproliferative thrombocytopenia, a large proportion of pediatric hematology/oncology patients continue to suffer from clinically significant bleeding. Antifibrinolytic (AF) drugs have been shown in certain surgical and trauma settings to decrease bleeding, blood transfusion, and improve survival. We conducted a retrospective assessment of the safety of using AF drugs in pediatric patients with hypoproliferative thrombocytopenia at our center as well as the impact on bleeding occurrence and severity.
Severe cytokine release syndrome in a patient receiving PD‐1‐directed therapy
Authors: Rotz Seth J. , Leino Daniel , Szabo Sara , Mangino Jennifer L. , Turpin Brian K. , Pressey Joseph G.
Published: May 2017

Cytokine release syndrome (CRS) is a phenomenon of immune hyperactivation described in the setting of cellular and bispecific T‐cell engaging immunotherapy. Checkpoint blockade using anti‐programmed cell death 1 (anti‐PD‐1) inhibitors is an approach to antitumor immune system stimulation. A 29‐year‐old female with alveolar soft part sarcoma developed severe CRS after treatment with anti‐PD‐1 therapy. CRS was characterized by high fevers, encephalopathy, hypotension, hypoxia, hepatic dysfunction, and evidence of coagulopathy, and resolved after infusion of the interleukin‐6 inhibitor tocilizumab and corticosteroids.
The effect of surface modification of Palygorskite on the morphology, mechanical, and thermal properties of Nylon 6/Palygorskite nanocomposites prepared by melt compounding
Authors: Cisneros‐Rosado D.E. , Paz‐Alpuche E.F. , Uribe‐Calderon J.A.
Published: May 2017

The effect of surface modification of Palygorskite (Pal) on the morphology and the mechanical and thermal properties of Nylon 6/Palygorskite nanocomposites, prepared by melt compounding, was investigated. A Pal mineral was purified, characterized, and surface modified separately with 3‐Aminopropyl trimethoxysilane and tributylhexadecyl‐phosphonium bromide in order to produce polymer nanoreinforcements. Organo‐Pals were characterized through SEM/EDX, FTIR, TGA, and XPS; surface energy was also determined. Experimental evidence confirmed the grafting of surface agents on the Pal surface; as expected, organo‐Pals exhibited high thermal stability and lower surface energy. Nylon 6/clay nanocomposites were melt‐compounded with different Pals at low Pal loadings. Pal dispersion was assessed by SEM and the thermal and mechanical properties were determined. In general, Pal exhibiting lower surface energy produced Nylon 6/Pal nanocomposites with improved Pal dispersion and properties. Pal particles favored the formation of γ crystalline form and increased the decomposition temperature of Nylon 6. The Pal aspect ratio in the Nylon 6/Pal nanocomposites was estimated from the experimental values of the elastic modulus using the Halpin–Tsai model; in addition, the Pal‐Nylon 6 interactions were estimated from the experimental values of the yield strength of nanocomposites with the Pukanszky's model. POLYM. COMPOS., 39:E1531–E1543, 2018. © 2017 Society of Plastics Engineers
Chemical treatment of cotton stalk and its effects on mechanical, rheological and morphological properties of Polypropylene/cotton stalk bio‐composites
Authors: Sachan Abhishek , Choudhary Veena , Vimal K.K. , Kapur G.S.
Published: May 2017

Cotton stalk as commercially viable bio fiber for preparing bio‐composites is explored of late, and the effects of various chemical treatments of cotton stalk fiber on mechanical, rheological and morphological properties of Polypropylene (PP)‐Cotton stalk (CS) bio‐composites are reported in this study. PP‐CS bio‐composites were prepared by varying the amount of cotton stalk from 10 to 50% by melt mixing in twin screw extruder and then injection molded to make specimen. PP‐CS bio‐composites with 50 wt% untreated CS were found to have maximum improvement in tensile modulus (83%), flexural modulus (120%), impact strength (39%). Similar to tensile and flexural modulus, the storage modulus of the PP‐CS composites was also increased with incorporation of CS into the PP matrix. To further increase the interaction between CS and PP matrix, four different chemical treatments (alkali, silane, permanganate solution and stearic acid) were tested for mechanical properties of CS‐PP bio‐composites. Among them KMnO4 treatment was found most effective on overall enhancement of bio‐composite properties. Chemically treated CS‐PP bio‐composites could be an economic viable option to prepare high quality low cost composites for suitable applications in various interior parts of automotives and house hold products. POLYM. COMPOS., 39:E286–E296, 2018. © 2017 Society of Plastics Engineers
Quantitative proteomic analysis of host epithelial cells infected by Salmonella enterica serovar Typhimurium
Authors: Qi Linlu , Hu Mo , Fu Jiaqi , Liu Yanhua , Wu Mei , Yu Kaiwen , Liu Xiaoyun
Published: May 2017

Systems‐level analyses have the capability to offer new insight into host–pathogen interactions on the molecular level. Using Salmonella infection of host epithelial cells as a model system, we previously analyzed intracellular bacterial proteome as a window into pathogens’ adaptations to their host environment [Infect. Immun. 2015; J. Proteome Res. 2017]. Herein we extended our efforts to quantitatively examine protein expression of host cells during infection. In total, we identified more than 5000 proteins with 194 differentially regulated proteins upon bacterial infection. Notably, we found marked induction of host integrin signaling and glycolytic pathways. Intriguingly, up‐regulation of host glucose metabolism concurred with increased utilization of glycolysis by intracellular Salmonella during infection. In addition to immunoblotting assays, we also verified the up‐regulation of PARP1 in the host nucleus by selected reaction monitoring and immunofluorescence studies. Furthermore, we provide evidence that PARP1 elevation is likely specific to Salmonella infection and independent of one of the bacterial type III secretion systems. Our work demonstrates that unbiased high‐throughput proteomics can be used as a powerful approach to provide new perspectives on host–pathogen interactions.
Differential protein expression in exosomal samples taken from trauma patients
Authors: Moyron Ron B. , Gonda Amber , Selleck Matthew J. , Luo‐Owen Xian , Catalano Richard D , O'Callahan Thomas , Garberoglio Carlos , Turay David , Wall Nathan R.
Published: May 2017

Traumatic brain injuries (TBI) are among the most misdiagnosed and underreported types of head trauma. The potential long‐term impact of undiagnosed or incorrectly identified concussions and other head injuries are potentially devastating, as evidenced by the increasing societal burden exhibited by soldiers returning from combat and athletes in contact sports. Concussions and TBI are notoriously difficult to correctly diagnose and prognosis for these injuries is poorly understood. In order to increase the likelihood of successful diagnosis, treatment, and prediction of outcomes, a definitive differential diagnosis will need to be established. The establishment of a “trauma–specific profile” or a panel of known trauma markers will significantly aid in this goal. Small membrane vesicles called exosomes have been shown to contain proteins and injury‐specific biomarkers. In the future it is possible that they could become an important tool, utilized for their diagnostic and therapeutic potential.
Pyrethroid resistance associated with M918 L mutation and detoxifying metabolism in Aphis gossypii from Bt cotton growing regions of China
Authors: Chen Xuewei , Tie Minyuan , Chen Anqi , Ma Kangsheng , Li Fen , Liang Pingzhuo , Liu Ying , Song Dunlun , Gao Xiwu
Published: May 2017

BACKGROUND

The cotton aphid, Aphis gossypii (Glover), is a destructive pest that affects numerous crops throughout the world. Pyrethroid resistance has become endemic in A. gossypii populations in the cotton growing areas of China due to wide‐ spread application of insecticides. To assess the extent of pyrethroid resistance, bioassays were conducted on field populations collected from several cotton cultivation areas from 2010 to 2015. The frequency of a known resistance‐associated sodium channel mutation (M918 L) in A. gossypii was evaluated and the bioassay of bifenthrin with or without the synergist was performed to illuminate the mechanisms underlying resistance to pyrethroids.

RESULTS

The field populations exhibited very high levels of resistance to both beta‐cypermethrin and deltamethrin. Pretreatment with synergists, DEF and PBO, significantly increased the toxicity of bifenthrin to cotton aphid populations collected from Bt cotton fields in China. Further, 96.8–100% of individuals with the M918 L mutation (including both RR and RS individuals) were observed in various populations, and only 2.8–3.2% of individuals with wild‐type homozygotes (SS) were detected.

CONCLUSION

The mutation M918 L in the voltage‐gated sodium channel along with detoxifying metabolism was contributed to the pyrethroid resistance in the field populations of Aphis gossypii from cotton growing regions of China. And insecticides with different modes of action should be recommended for the control of A. gossypii in the future. © 2017 Society of Chemical Industry
Protection status and national socio‐economic context shape land conversion in and around a key transboundary protected area complex in West Africa
Authors: Schulte to Bühne Henrike , Wegmann Martin , Durant Sarah M. , Ransom Chris , de Ornellas Paul , Grange Sophie , Beatty Hope , Pettorelli Nathalie
Published: May 2017

Transboundary cooperation is being promoted as an effective way to conserve biodiversity that straddles national borders. However, monitoring the ecological outcomes of these large‐scale endeavours is challenging, and as a result, the factors and processes likely to shape their effectiveness remain poorly identified and understood. To address this knowledge gap, we tested three hypotheses pertaining to natural vegetation loss across the W‐Arly‐Pendjari protected area complex, a key biodiversity hotspot in West Africa. Using a new methodology to compare land cover change across large remote areas where independent validation data is unevenly distributed across time, we demonstrate widespread agricultural expansion outside protected areas over the past 13 years. Protected areas with high protection status appear considerably more effective at preventing land conversion than other protected areas. We moreover report marked differences in cropland expansion rates between countries, which we suggest may be linked to differences in rural population growth. Altogether, our results suggest that there can be considerable spatial heterogeneity in anthropogenic pressure across transboundary protected area complexes and call for more comprehensive assessments that capitalize on the current availability of remote sensing information.
Seismic assessment of concrete buildings reinforced with shape memory alloy materials in different stories
Authors: Shiravand M. R. , Nashtaee M. A. , Veismoradi S.
Published: May 2017

Shape memory alloy (SMA) is a unique material with many beneficial characteristics such as superelasticity and excellent resistance against corrosion. However, the high expenses related to the material costs and difficulties associated with implementation of SMAs in reinforced concrete (RC) structures may limit their usage. To decrease the costs related to SMA installation, this paper investigates the seismic performance of RC moment‐resisting frames with the intention of specifying the optimal stories for SMA utilization. To this end, RC frames with 3, 5, 7, and 9 stories are modeled and various cases are considered for SMA locations in different story levels. For each building, 4 different cases are considered including a frame with regular steel reinforcement (Steel), a frame with SMAs in all story levels (full SMA), and 2 remaining cases consist of frames with SMAs in bottom and middle story levels only. In the first part, nonlinear dynamic time history analyses are conducted to evaluate the base shear, roof displacement, interstory, and residual drift demands of the structures using 10 ground‐motion records. In the second part, the incremental dynamic analysis is employed to assess the entire range of structural dynamic behavior. By using the generated data from incremental dynamic analysis procedure, fragility evaluation is conducted on multiple limit states to provide a comprehensive performance assessment for each case. The results indicate that frames with SMA in their lower story levels performed similar to frames equipped with SMA in all story levels. However, the fragility assessments show the better performance of frames with SMA in their bottom stories versus other cases. On this basis, the costs associated with SMA fabrication could be reduced noticeably (nearly two‐thirds) without sacrificing the overall performance of the frame and its post‐earthquake serviceability.
Will the Paris Agreement accelerate the pace of change?
Authors: Morgan Jennifer , Northrop Eliza
Published: May 2017

Since adoption of the Kyoto Protocol under the United Nations Framework Convention on Climate Change in 1997, the international climate regime has been caught in stasis. Due to a lack of direction and clarity at the policy level and deep political divides, the evolution of the international climate regime under the United Nations Framework Convention on Climate Change (UNFCCC) had failed to catch up with the changes occurring in the real economy. The momentum created ahead of COP21 in 2015 and resulting Paris Agreement has changed this, creating a new paradigm of international climate policy, politics and cooperation that is, if implemented, capable of generating the momentum needed to accelerate the pace of change and drive transformation. This new paradigm that emerged from the Paris Agreement, demonstrates the role of the United Nations in giving voice to smaller countries to create effective positive powerful coalitions and the need to invite the outside world into the process through greater participation of cities, business, investors and other non‐state actors. We outline the main policy and political shifts that the Paris Agreement represents, and explain why this new paradigm of international climate policy, politics and cooperation is key to accelerating the pace of change and keeping the world well below 2°C, and optimally 1.5°C. WIREs Clim Change 2017, 8:e471. doi: 10.1002/wcc.471

This article is categorized under:

Policy and Governance > International Policy Framework
Global sensitivity analysis of the blade geometry variables on the wind turbine performance
Authors: Echeverría Fernando , Mallor Fermín , San Miguel Unai
Published: May 2017

The need for implementing efficient blade designs gains relevance as wind turbine developments require longer blades. The design of blade geometry, traditionally divided in 2D airfoils and spanwise distributions, is usually addressed as an optimization problem. A correct identification of the design variables is crucial to avoid unnecessary computational cost or insufficient exploration of the design space. This paper deals with the identification of the design variables that affect the wind turbine performance.

First, the number of design variables for an accurate airfoil representation is resolved. A methodology, based on statistical hypothesis testing applied to the airfoil approximation errors, is presented to assess the accuracy of types of B‐splines.

Second, the study is extended to chord and twist distributions besides airfoil geometry with the purpose of assessing the sensitive blade variables in the wind turbine performance. Global sensitivity analysis as multi‐variable linear regressions and variance‐based methods are used. Latin hypercube sampling is applied to generate efficient inputs. MATLAB‐based code is developed to obtain outputs: annual energy production, maximum blade tip deflection, overall sound power level and blade mass.

As result of the study, a list of non‐affecting variables is deduced. These variables can be avoided in the optimization without loss of gain in the performance. The method is a powerful tool to analyse in a preliminary phase a design problem involving a high amount of variables and complex physical relations by means of combining different multi‐disciplinar calculation codes and performing statistical treatments. Copyright © 2017 John Wiley & Sons, Ltd.
Metabolic engineering of Saccharomyces cerevisiae for production of germacrene A, a precursor of beta-elemene
Authors: Hu Yating , Zhou Yongjin J , Bao Jichen , Huang Luqi , Nielsen Jens , Krivoruchko Anastasia
Published: May 2017

Beta-elemene, a sesquiterpene and the major component of the medicinal herb Curcuma wenyujin, has antitumor activity against various types of cancer and could potentially serve as a potent antineoplastic drug. However, its current mode of production through extraction from plants has been inefficient and suffers from limited natural resources. Here, we engineered a yeast cell factory for the sustainable production of germacrene A, which can be transformed to beta-elemene by a one-step chemical reaction in vitro. Two heterologous germacrene A synthases (GASs) converting farnesyl pyrophosphate (FPP) to germacrene A were evaluated in yeast for their ability to produce germacrene A. Thereafter, several metabolic engineering strategies were used to improve the production level. Overexpression of truncated 3-hydroxyl-3-methylglutaryl-CoA reductase and fusion of FPP synthase with GAS, led to a sixfold increase in germacrene A production in shake-flask culture. Finally, 190.7 mg/l of germacrene A was achieved. The results reported in this study represent the highest titer of germacrene A reported to date. These results provide a basis for creating an efficient route for further industrial application re-placing the traditional extraction of beta-elemene from plant sources.
“It was a lot Tougher than I Thought It would be”. A Qualitative Study on the Changing Nature of Being a Hemophilia Carrier
Authors: von der Lippe Charlotte , Frich Jan C. , Harris Anna , Solbrække Kari Nyheim
Published: May 2017

Studies on carriers of genetic disorders mainly focus on the process of genetic testing and reproductive choices, and less on how psychosocial aspects of being a carrier change over time. Our study sought to understand more about the psychosocial aspects of hemophilia carrier status, and thereby improve counseling aiming to advance carriers’ quality of life and well‐being. We analyzed 16 in‐depth interviews from women who were carriers of hemophilia and had a son with hemophilia. Three themes emerged: Guilt and sorrow across generations; the choices and future consequences of genetic testing; and preparing to have a child with hemophilia. Experience with being a hemophilia carrier is a process that changes over time while feelings of guilt and sorrow run across generations. The carrier status may create “mothers‐in‐waiting” living at risk of having a sick child or not. The women think they are prepared to have a son with hemophilia, but experience more sadness than they expect when a son is diagnosed. Our findings suggest that health professionals, especially clinical geneticists and genetic counselors, carriers, families and patient organizations need to be aware that women's experiences of being a carrier of hemophilia changes during the biographical life course. The women may benefit from several rounds of genetic counseling at different stages of life.
Outcomes Following Operative Treatment of Adolescent Mallet Fractures
Authors: Chen Andrew T. , Conry Keegan T. , Gilmore Allison , Son-Hing Jochen P. , Liu Raymond W.
Published: May 2017

Background

Many surgeons advocate for surgical intervention of adult mallet fractures that involve either subluxation of the distal interphalangeal (DIP) joint or those that involve more than one-third of the articular surface. However, the efficacy of operative treatment and complication rates are unclear regarding the adolescent population.

Questions/Purposes

The goal of this study is to evaluate the clinical outcomes following operative fixation of bony mallet fractures in the adolescent population.

Methods

Seventeen patients with bony mallet fractures treated surgically were retrospectively reviewed. Twelve patients were treated by closed reduction with extension block pinning. The other patients underwent an open reduction and pin fixation. The average age was 15.2 years (13–18). Most injuries were sport related. The average time from injury to presentation was 17 days and from injury to surgery was 24.5 days. Nine patients had subluxation at the DIP joint and all involved at least one-third of the articular surface.

Results

The average time from surgery to pin removal was 28 days (19–46). All distal phalanx physis were closed or nearly closed. One patient reported pain at the final follow-up. Two patients (11.8%) had major complications. One had an extension contracture postoperatively, did not attend therapy, and re-fractured 5 months later requiring reoperation. The second was treated delayed (32 days) and lost fixation, requiring revision surgery and antibiotics for a superficial infection. Two patients with delayed treatment (32 and 44 days) had an extensor lag (11.8%).

Conclusions

Operative treatment of mallet fractures with subluxation or involving more than one-third of the articular surface appears effective. Pin removal 4 weeks postoperatively appears adequate. Complications occurred with delayed presentation and non-compliance.
TESTIMONY, RECOVERY AND PLAUSIBLE DENIABILITY: A RESPONSE TO PEET
Authors: Davies Alex
Published: May 2017

According to telling based views of testimony (TBVs), B has reason to believe that p when A tells B that p because A thereby takes public responsibility for B's subsequent belief that p. Andrew Peet presents a new argument against TBVs. He argues that insofar as A uses context-sensitive expressions to express p, A doesn't take public responsibility for B's belief that p. Since context-sensitivity is widespread, the kind of reason TBVs say we have to believe what we're told, is not widespread. Peet doesn't identify any problem with his own argument though he does attempt to limit its sceptical potential by identifying special contexts in which TBVs stand a chance of success. A more general defence of TBVs can be provided by showing Peet's argument to be unsound. I argue that Peet's argument is unsound because it requires us to wrongly suppose that speakers do far less labour than their audiences in context-sensitive linguistic communication. I aim to show why – in the context of the epistemology of testimony and the philosophy of language – it's important to recognize the labour that speakers can do, and so can be held responsible for not doing, in episodes of context-sensitive linguistic communication.
Aerothermodynamic correlations for high-speed flow
Authors: Singh Narendra , Schwartzentruber Thomas E.
Published: May 2017

Heat flux and drag correlations are developed for high-speed flow over spherical geometries that are accurate for any Knudsen number ranging from continuum to free-molecular conditions. A stagnation point heat flux correlation is derived as a correction to the continuum (Fourier model) heat flux and also reproduces the correct heat flux in the free-molecular limit by use of a bridging function. In this manner, the correlation can be combined with existing continuum correlations based on computational fluid dynamics simulations, yet it can now be used accurately in the transitional and free-molecular regimes. The functional form of the stagnation point heat flux correlation is physics based, and was derived via the Burnett and super-Burnett equations in a recent article, Singh & Schwartzentruber (J. Fluid Mech., vol. 792, 2016, pp. 981–996). In addition, correlation parameters from the literature are used to construct simple expressions for the local heat flux around the sphere as well as the integrated drag coefficient. A large number of direct simulation Monte Carlo calculations are performed over a wide range of conditions. The computed heat flux and drag data are used to validate the correlations and also to fit the correlation parameters. Compared to existing continuum-based correlations, the new correlations will enable engineering analysis of flight conditions at higher altitudes and/or smaller geometry radii, useful for a variety of applications including blunt body planetary entry, sharp leading edges, low orbiting satellites, meteorites and space debris.
Dynamics and Stability of Pinned-Free Micropipes Conveying Fluid
Authors: Hu K. , Dai H. L. , Wang L. , Qian Q.
Published: May 2017

In this paper, the dynamical behavior and stability of hanging micropipes conveying fluid with pinned-free boundary conditions are investigated. For a pinned-free rigid micropipe, the dynamical system is found to be stable for various flow velocities. Particular emphasis is placed on the effects of flow velocity, mass ratio and gravity on the dynamics and flutter instability of flexible micropipe system with pinned-free boundary conditions. The governing equations for flexible micropipes are discretized using the differential quadrature method (DQM), yielding a generalized eigenvalue problem which is then solved for various flow velocities, mass ratios and gravity parameters. It is shown that, with increasing flow velocity, the flexible micropipe with pinned-free boundary conditions is stable until it becomes unstable via a Hopf bifurcation leading to flutter. The system may lose stability first in the second or third mode, mainly depending on the selected value of mass ratio. The existence of mode exchange between the second and third modes is possible. The gravity parameter of positive values causes additional restoring force and hence enhances the stability of the micropipe system; however, it can generate the complexity of stability diagrams.
How Social Are Social Media? A Review of Online Social Behaviour and Connectedness
Authors: Ryan Tracii , Allen Kelly A. , Gray DeLeon L. , McInerney Dennis M.
Published: May 2017

The use of social media is rapidly increasing, and one of the major discussions of the 21st century revolves around how the use of these applications will impact on the social relationships of users. To contribute to this discussion, we present a brief narrative review highlighting the advantages and disadvantages of social media use on three key aspects of social connectedness: social capital, sense of community, and loneliness. The results indicate that using social media can increase social capital, lead to the formation of friendships and communities, and reduce loneliness. However, some social media site users may experience weakening friendships, online ostracism, and heightened loneliness. Therefore, we argue that the use of social media has contradictory effects on social connectedness. Moreover, the direction of these outcomes is contingent upon who is using the site and how they are using it. Based on these arguments, possible directions for future research are discussed. It is recommended that discourse be continued relating to the association between online social behaviour and connectedness, as this will enable researchers to establish whether the positive outcomes of social media use outweigh the negative.
Holocene climatic and environmental change on the western Tibetan Plateau revealed by glycerol dialkyl glycerol tetraethers and leaf wax deuterium-to-hydrogen ratios at Aweng Co
Authors: Li Xiumei , Wang Mingda , Zhang Yuzhi , Lei Li , Hou Juzhi
Published: May 2017

Mean annual air temperature (MAAT) and precipitation isotope records for the Holocene were obtained from the analysis of the relative distribution of branched glycerol dialkyl glycerol tetraethers and compound-specific hydrogen isotope ratios of leaf waxes from a sediment core from Aweng Co on the western Tibetan Plateau (WTP). Our results indicate that the Indian monsoon mainly influenced Aweng Co during the Holocene. During the early Holocene, when summer insolation was at a maximum, the monsoonal influence was strong and the climate was warm and wet. Both the summer and winter insolation were relatively weak, and Aweng Co was cool and dry during the middle Holocene (6–3 ka), indicating a weakening of the Indian monsoon. The southward displacement of the Intertropical Convergence Zone and relatively low atmospheric methane content may have contributed to the middle Holocene cooling on the WTP. During the late Holocene, with a further increase in winter insolation and decrease in summer insolation, the summer monsoon weakened and the MAAT on the WTP gradually increased. Depleted leaf wax hydrogen isotope ratios during the late Holocene can be attributed to accelerated glacier melting because of the elevated MAAT.
Controls on fracture distribution in Cretaceous sedimentary rocks from the Isfahan region, Iran
Authors: SAEIN ALI FARZIPOUR , RIAHI ZAHRA TAJMIR
Published: May 2017

In this study, relationships between fracture patterns, lithology, thickness, diagenetic processes and grain size are evaluated within Cretaceous sediments in two sections of Dizlu and Kolah Ghazi of Isfahan. This study area was selected based on its outcrops of different rock units and its well-developed tectonic fractures. The fracture patterns within stratigraphic units of these sections are studied using geometrical and statistical analyses. This study finds that variable fracture spacing and fracture spacing ratios can be affected by lithology, thickness, grain size of sediments and diagenetic processes. A study of fracture stratigraphy based on fracture pattern evaluation within different cropped-out sedimentary rocks can be used to improve understanding of the same types of sedimentary rock units below the surface or throughout other sedimentary basins. Consequently, this could improve information regarding storage and fluid flow pattern throughout sedimentary rocks in different regions, even for subsurface purposes.
Is It Desirable to Be Able to Do the Undesirable? Moral Bioenhancement and the Little Alex Problem
Authors: HAUSKELLER MICHAEL
Published: May 2017

It has been argued that moral bioenhancement is desirable even if it would make it impossible for us to do what is morally required. Others find this apparent loss of freedom deplorable. However, it is difficult to see how a world in which there is no moral evil can plausibly be regarded as worse than a world in which people are not only free to do evil, but also where they actually do it, which would commit us to the seemingly paradoxical view that, under certain circumstances, the bad can be better than the good. Notwithstanding, this view is defended here.
Moral Bioenhancement and Free Will: Continuing the Debate
Authors: RAKIĆ VOJIN
Published: May 2017

This article continues and expands differences I have with Ingmar Persson and Julian Savulescu concerning issues of moral bioenhancement and free will. They have criticized my conception of voluntary moral bioenhancement, claiming that it ignores the extent to which freedom is a matter of degree. Here, I argue that freedom as a political concept (or as one that is analogous to a political concept) is indeed scalar in nature, but that freedom of the will is to be understood as a threshold concept and therefore not as subject to degree. Consequently, I contend, by asserting that freedom is a matter of degree, that Persson and Savulescu have not undermined my arguments favoring voluntary moral enhancement. In addition, I add three further arguments against compulsory moral bioenhancement.
Would We Even Know Moral Bioenhancement If We Saw It?
Authors: WISEMAN HARRIS
Published: May 2017

The term “moral bioenhancement” conceals a diverse plurality encompassing much potential, some elements of which are desirable, some of which are disturbing, and some of which are simply bland. This article invites readers to take a better differentiated approach to discriminating between elements of the debate rather than talking of moral bioenhancement “per se,” or coming to any global value judgments about the idea as an abstract whole (no such whole exists). Readers are then invited to consider the benefits and distortions that come from the usual dichotomies framing the various debates, concluding with an additional distinction for further clarifying this discourse qua explicit/implicit moral bioenhancement.
Imagining Moral Bioenhancement Practices: Drawing Inspiration from Moral Education, Public Health Ethics, and Forensic Psychiatry
Authors: SPECKER JONA , SCHERMER MAARTJE H.N.
Published: May 2017

In this article, we consider contexts or domains in which (future) moral bioenhancement interventions possibly or most likely will be implemented. By looking closely at similar or related existing practices and their relevant ethical frameworks, we hope to identify ethical considerations that are relevant for evaluating potential moral bioenhancement interventions. We examine, first, debates on the proper scope of moral education; second, proposals for identifying early risk factors for antisocial behaviour; and third, the difficult balancing of individual freedom and third party concerns in (forensic) psychiatry. In imagining moral bioenhancement in practice, we observe that unlike other forms of enhancement, moral enhancement fundamentally asks how the interests and preferences of the individual and the interests of others should be weighed (in view of public safety and managing public risk). Highly diverse domains such as education, mental health, and the judicial domain might be involved, and moral bioenhancement might challenge existing institutional settings. Given these highly varied contexts and domains, it appears unlikely that there will be a distinct set of practices that will be referred to as “moral bioenhancement.”
Cross-resistance Patterns to Acetyl-CoA Carboxylase Inhibitors Associated with Different Mutations in Japanese Foxtail (Alopecurus japonicus)
Authors: Chen Guoqi , Wang Lingyue , Xu Hongle , Wu Xibao , Pan Lang , Dong Liyao
Published: May 2017

Japanese foxtail is a grass weed in eastern China. This weed is controlled by fenoxaprop-P-ethyl, one of the most common acetyl-CoA carboxylase (ACCase)-inhibiting herbicides. Some Japanese foxtail populations have developed resistance to fenoxaprop-P-ethyl, owing to target-site mutations (amino acid substitutions) located within the carboxyl transferase domain of ACCase. In the present study, three mutations were detected in three fenoxaprop-P-ethyl–resistant Japanese foxtail populations: Ile-1781-Leu in JCJT-2, Ile-2041-Asn in JZJR-1, and Asp-2078-Gly in JCWJ-3. Two copies ofACCase(Acc1-1andAcc1-2) were identified, but mutations were detected only inAcc1-1. The derived cleaved amplified polymorphic sequence (dCAPS) method detected these mutations successfully in Japanese foxtail. The mutation frequencies in JCJT-2, JZJR-1, and JCWJ-3 were approximately 98%, 92%, and 87%, respectively. Different cross-resistance patterns to ACCase inhibitors were found in the three resistant populations. JCJT-2 (Ile-1781-Leu) and JZJR-1 (Ile-2041-Asn) showed cross-resistance to haloxyfop-R-methyl, clodinafop-propargyl, and pinoxaden, but were susceptible to clethodim. JCWJ-3 (Asp-2078-Gly) showed cross-resistance to all tested ACCase-inhibiting herbicides.
Inhibition of SDF-1 receptors CXCR4 and CXCR7 attenuates acute pulmonary inflammation via the adenosine A2B-receptor on blood cells
Authors: Konrad Franziska Magdalena , Meichssner Nadine , Bury Annette , Ngamsri Kristian-Christos , Reutershan Jörg
Published: May 2017

Acute pulmonary inflammation is characterized by migration of polymorphonuclear neutrophils into the different compartments of the lung. Recent studies showed evidence that the chemokine stromal cell-derived factor (SDF)-1 and its receptors CXCR4 and CXCR7 influence migration of immune cells and their activity was linked to adenosine concentrations. We investigated the particular role of CXCR4- and CXCR7-inhibition and the potential link to the adenosine A2B-receptor, which plays an important anti-inflammatory role in the lung. After LPS-inhalation for 45 minutes, administration of the CXCR4-inhibitor (AMD3100) decreased transendothelial and transepithelial migration, whereas CXCR7-antagonism influenced epithelial migration exclusively. In A2B−/− mice, no anti-inflammatory effects were detectible through either one of the agents. Using chimeric mice, we identified A2Bon hematopoietic cells to be crucial for these anti-inflammatory effects of CXCR4/7-inhibition. Both inhibitors decreased TNFα, IL6, CXCL1 and CXCL2/3 levels in the bronchoalveolar lavage of wild type mice, while not influencing the chemokine release in A2B−/− mice. Inflammation augmented the expression of both receptors and their inhibition increased A2B-levels upon inflammation.In vitroassays with human epithelium/endothelium confirmed ourin vivofindings. During inflammation, inhibition of CXCR4- and CXCR7-receptors prevented microvascular permeability in wild type but not in A2B−/− mice, highlighting the pivotal role of an active A2B-receptor in this setting. The combination of both inhibitors had a synergistic effect in preventing capillary leakage. In conclusion, we determined the pivotal role of CXCR4- and CXCR7-inhibition in acute pulmonary inflammation, which depended on A2B-receptor signalling.
Deletion of Pdcd5 in mice led to the deficiency of placenta development and embryonic lethality
Authors: Li Ge , Xu Chentong , Lin Xin , Qu Liujing , Xia Dan , Hongdu Beiqi , Xia Yan , Wang Xiaokun , Lou Yaxin , He Qihua , Ma Dalong , Chen Yingyu
Published: May 2017

Programmed cell death 5 (PDCD5) is an apoptosis promoter molecule that displays multiple biological activities. However, the function of PDCD5 in vivo has not yet been investigated. Here, we generated a Pdcd5 knockout mouse model to study the physiological role of PDCD5 in vivo. Knockout of the Pdcd5 gene resulted in embryonic lethality at mid-gestation. Histopathological analysis revealed dysplasia in both the LZs and JZs in Pdcd5–/– placentas with defects in spongiotrophoblasts and trophoblast giant cells. Furthermore, Pdcd5–/– embryos had impaired transplacental passage capacity. We also found that Pdcd5–/– embryos exhibited cardiac abnormalities and defective liver development. The growth defect is linked to impaired placental development and may be caused by insufficient oxygen and nutrient transfer across the placenta. These findings were verified in vitro in Pdcd5 knockout mouse embryonic fibroblasts, which showed increased apoptosis and G0/G1 phase cell cycle arrest. Pdcd5 knockout decreased the Vegf and hepatocyte growth factor (Hgf) levels, downregulated the downstream Pik3ca–Akt–Mtor signal pathway and decreased cell survival. Collectively, our studies demonstrated that Pdcd5 knockout in mouse embryos results in placental defects and embryonic lethality.
Protein disulfide isomerase-mediated apoptosis and proliferation of vascular smooth muscle cells induced by mechanical stress and advanced glycosylation end products result in diabetic mouse vein graft atherosclerosis
Authors: Ping Suning , Liu Shuying , Zhou Yuhuan , Li Ziqing , Li Yuhuang , Liu Kefeng , Bardeesi Adham SA , Wang Linli , Chen Jingbo , Deng Lie , Wang Jingjing , Wang Hong , Chen Dadi , Zhang Zhengyu , Sheng Puyi , Li Chaohong
Published: May 2017

Protein disulfide isomerase (PDI) involves cell survival and death. Whether PDI mediates mechanical stretch stress (SS) and/or advanced glycosylation end products (AGEs) -triggered simultaneous increases in proliferation and apoptosis of vascular smooth muscle cells (VSMCs) is unknown. Here, we hypothesized that different expression levels of PDI trigger completely opposite cell fates among the different VSMC subtypes. Mouse veins were grafted into carotid arteries of non-diabetic and diabetic mice for 8 weeks; the grafted veins underwent simultaneous increases in proliferation and apoptosis, which triggered vein graft arterializations in non-diabetic or atherosclerosis in diabetic mice. A higher rate of proliferation and apoptosis was seen in the diabetic group. SS and/or AGEs stimulated the quiescent cultured VSMCs, resulting in simultaneous increases in proliferation and apoptosis; they could induce increased PDI activation and expression. Both in vivo and in vitro, the proliferating VSMCs indicated weak co-expression of PDI and SM-α-actin while apoptotic or dead cells showed strong co-expression of both. Either SS or AGEs rapidly upregulated the expression of PDI, NOX1 and ROS, and their combination had synergistic effects. Inhibiting PDI simultaneously suppressed the proliferation and apoptosis of VSMCs, while inhibition of SM-α-actin with cytochalasin D led to increased apoptosis and cleaved caspases-3 but had no effect on proliferation. In conclusion, different expression levels of PDI in VSMCs induced by SS and/or AGEs triggered a simultaneous increase in proliferation and apoptosis, accelerated vein graft arterializations or atherosclerosis, leading us to propose PDI as a novel target for the treatment of vascular remodeling and diseases.