bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of empathy in preparing teachers to tackle bullying
Authors: Murphy Helena , Tubritt John , Norman James O’Higgins
Published: January 2018

Much research on bullying behaviour in schools among students has been carried out since the 1970’s, when Olweus started a large-scale project in Norway which is now generally regarded as the first scientific study on bullying. Yet, there has been little research on how teachers respond to reports of bullying and tackle bullying behaviour in post-primary schools. This paper reports on a preliminary study investigating teacher empathy levels and their preparedness for tackling bullying in a post-primary school in Ireland. There were two research questions central to this research. The first looked at how empathic are teachers in this school? The second examined to what extent it prepares them for tackling bullying? In answering these questions we relied on the Interpersonal Reactivity Index (IRI) to gather data on empathy levels among teachers (n=10), with findings related to existing research in the field. The results showed that teacher empathy is an important factor in creating and maintaining a positive school climate, which in turn leads to a prevention of bullying situations.
The multipotency‐to‐commitment transition in Caenorhabditis elegans—implications for reprogramming from cells to organs
Authors: Spickard Erik A. , Joshi Pradeep M. , Rothman Joel H.
Published: January 2018

In animal embryos, cells transition from a multipotential state, with the capacity to adopt multiple fates, into an irreversible, committed state of differentiation. This multipotency‐to‐commitment transition (MCT) is evident from experiments in which cell fate is reprogrammed by transcription factors for cell type‐specific differentiation, as has been observed extensively in Caenorhabditis elegans. Although factors that direct differentiation into each of the three germ layer types cannot generally reprogram cells after the MCT in this animal, transcription factors for endoderm development are able to do so in multiple differentiated cell types. In one case, these factors can redirect the development of an entire organ in the process of “transorganogenesis”. Natural transdifferentiation also occurs in a small number of differentiated cells during normal C. elegans development. We review these reprogramming and transdifferentiation events, highlighting the cellular and developmental contexts in which they occur, and discuss common themes underlying direct cell lineage reprogramming. Although certain aspects may be unique to the model system, growing evidence suggests that some mechanisms are evolutionarily conserved and may shed light on cellular plasticity and disease in humans.
SKS Splitting and the Scale of Vertical Coherence of the Taiwan Mountain Belt
Authors: Kuo Ban‐Yuan , Lin Shu‐Chuan , Lin Yi‐Wei
Published: January 2018

Many continental orogens feature a pattern of SKS shear wave splitting with fast polarization directions parallel to the mountain fabrics and delay times of 1–2 s, implying that the crust and lithosphere deform consistently. In the Taiwan arc‐continent collision zone, similar pattern of SKS splitting exists, and thereby lithospheric scale deformation due to collision has been assumed. However, recent dynamic modeling demonstrated that the SKS splitting in Taiwan can be generated by the toroidal flow in the asthenosphere induced by the subduction of the Philippine Sea plate and the Eurasian plate. To further evaluate this hypothesis, we analyzed a new data set using a quantitative approach. The results show that models with slab geometries constrained by seismicity explain the observed fast splitting direction to within 25°, whereas the misfit grows to ~50–60° if the toroidal flow is disrupted by the presence of a sizable aseismic slab beneath central Taiwan as often suggested by tomographic imaging. However, small sized aseismic slab or detached slab fragment can potentially reconcile the splitting observations. We estimated the scale of vertical coherence to be 10–40 km in the lithosphere and 100–150 km in the asthenosphere, making the former unfavorable for accumulating large delay times. The low coherence is caused by the subduction of the Eurasian plate that creates complex deformation different from what characterizes the compressional tectonics above the plate. This suggests that the mountain building in Taiwan is a shallow process, rather than lithospheric in scale.
ENSO Atmospheric Teleconnections and Their Response to Greenhouse Gas Forcing
Authors: Yeh Sang‐Wook , Cai Wenju , Min Seung‐Ki , McPhaden Michael J. , Dommenget Dietmar , Dewitte Boris , Collins Matthew , Ashok Karumuri , An Soon‐Il , Yim Bo‐Young , Kug Jong‐Seong
Published: January 2018

El Niño and Southern Oscillation (ENSO) is the most prominent year‐to‐year climate fluctuation on Earth, alternating between anomalously warm (El Niño) and cold (La Niña) sea surface temperature (SST) conditions in the tropical Pacific. ENSO exerts its impacts on remote regions of the globe through atmospheric teleconnections, affecting extreme weather events worldwide. However, these teleconnections are inherently nonlinear and sensitive to ENSO SST anomaly patterns and amplitudes. In addition, teleconnections are modulated by variability in the oceanic and atmopsheric mean state outside the tropics and by land and sea ice extent. The character of ENSO as well as the ocean mean state have changed since the 1990s, which might be due to either natural variability or anthropogenic forcing, or their combined influences. This has resulted in changes in ENSO atmospheric teleconnections in terms of precipitation and temperature in various parts of the globe. In addition, changes in ENSO teleconnection patterns have affected their predictability and the statistics of extreme events. However, the short observational record does not allow us to clearly distinguish which changes are robust and which are not. Climate models suggest that ENSO teleconnections will change because the mean atmospheric circulation will change due to anthropogenic forcing in the 21st century, which is independent of whether ENSO properties change or not. However, future ENSO teleconnection changes do not currently show strong intermodel agreement from region to region, highlighting the importance of identifying factors that affect uncertainty in future model projections.
Design of a Graphene‐Based Tunable Frequency Selective Surface and Its Application for Variable Radiation Pattern of a Dipole at Terahertz
Authors: Qu Meijun , Song Jiming , Yao Lidan , Li Shufang , Deng Li , Yang Yandong
Published: January 2018

In this paper, a frequency selective surface (FSS) with tunable bandstop performance by integrating graphene is discussed. The graphene implanted in the circular FSS unit makes the transmission and reflection bands of the proposed FSS tunable owing to its alterable complex conductivity controlled by the chemical potential. The transmission zero of the proposed FSS performing as a reflection plane happens at the frequency from 1.65 THz to 2.19 THz when the chemical potentials of graphene change from 0 eV to 1 eV. Moreover, reconfigurable radiation pattern of a traditional dipole antenna is accomplished loaded with the proposed FSS by altering the complex conductivity of graphene. The dipole has a directional radiation pattern with enhanced directivity at 2.1 THz by adding the proposed FSS with μc = 0.8 eV. However, the omnidirectional radiation pattern is maintained by changing the value of chemical potential to 0 eV while the FSS is nearly transparent. Therefore, a radiation diversity property could be achieved by controlling the chemical potential of graphene loaded in FSS.
Cretaceous‐Paleocene Evolution and Crustal Structure of the Northern Vøring Margin (Offshore Mid‐Norway): Results from Integrated Geological and Geophysical Study
Authors: Zastrozhnov D. , Gernigon L. , Gogin I. , Abdelmalak M. M. , Planke S. , Faleide J. I. , Eide S. , Myklebust R.
Published: January 2018

We present results of a multidisciplinary study of the northern segment of the Vøring volcanic rifted margin, offshore mid‐Norway. This segment represents a transitional margin domain that is less investigated compared to the adjacent segments of the margin. In order to understand the geological evolution of the study area, we performed an integrated interpretation of an extensive geological and geophysical data set. This data set includes recently acquired and reprocessed 2‐D reflection seismic, published refraction data and potential field data, as well as new borehole data. Two‐dimensional potential field modeling was performed to better assess the crustal architecture and evolution of the northern Vøring Margin. We then consider how crustal‐scale structures and processes affected the basin formation. The outer and distal northern Vøring Margin represents a series of deep Cretaceous (Træna Basin and Någrind Syncline) and Cretaceous‐Paleocene (Hel Graben) sag subbasins underlain by a significantly thinned continental crust. These subbasins developed in between structural highs (Utgard, Nyk, and Grimm Highs), which are underlain by a thicker crust and interpreted as a series of rigid continental blocks (“buffers”). In addition to the regional Late Jurassic‐Early Cretaceous rifting events, we found structural evidence of local Neocomian and mid‐Cretaceous extensional reactivation affecting the northern segment of the Vøring Basin. During the mid‐Late Cretaceous‐Paleocene, the extensional axis within the Vøring Basin province migrated sequentially northwestward to the present‐day continent‐ocean “boundary”. We also show fundamental differences between the volcanic rifted mid‐Norwegian Margin and nonvolcanic (Iberian‐type) margins and how preexisting structures events can shape the evolution and architecture of the margin.
Visuospatial counter‐interrogation strategies by liars familiar with the alibi setting
Authors: Deeb Haneen , Granhag Pär Anders , Vrij Aldert , Strömwall Leif A. , Hope Lorraine , Mann Samantha
Published: January 2018

This study examines counter‐interrogation strategies employed by liars giving false alibis. Participants (N = 144) visited a restaurant to buy a sandwich (truth‐tellers) or to use it as a false alibi (liars). Half of the liars were informed they might be asked for a drawing of the alibi setting if interviewed (informed liars). Participants spent either 10 min (high familiarity condition) or 30 s (low familiarity condition) in the restaurant. All participants were asked to provide two visuospatial statements, which were assessed for salient details, nonsalient details, between‐statement consistency, and statement‐alibi setting consistency. Informed liars provided significantly more salient and nonsalient details than uninformed liars and truth‐tellers, particularly in the high familiarity condition. No differences emerged for statement consistency types. The results suggest that liars are more concerned than truth‐tellers about making a positive impression on the interviewer, and they fail to accurately reflect on truth‐tellers' visuospatial statements.
The role of intonation for interrogative suggestibility
Authors: Gubi‐Kelm Silvia , Schmidt Alexander F.
Published: January 2018

The detrimental consequences of suggestive witness manipulation have been frequently discussed in the literature. Notably, these discussions have been limited to the consequences of suggestive question types and interrogator conduct. This study is the first to investigate the influence of interrogator's intonation on interrogative suggestibility. Specifically, utilizing a modified German version of the forensic Gudjonsson suggestibility scale as dependent variable, we experimentally manipulated phrase‐final contours (low vs. high) and accentuation of details (neutral vs. emphatic) in the questions of the interrogator in a student sample (N = 88). Phrase‐final falling intonation contours increased suggestibility both through suggestive questions and through negative feedback. In contrast, accentuation of selected details increased only the latter. The combination of both tonal patterns only partially influenced suggestive response behavior after the exposure to interrogative pressure. However, particularly the combination of phrase‐final rising and neutral intonation consistently led to lowest interrogative suggestibility. Results are discussed in terms of their theoretical and applied implications for forensic contexts.
Porous Titanium Implants: A Review
Authors: Pałka Krzysztof , Pokrowiecki Rafał
Published: January 2018

Titanium and its alloys are commonly used in almost all disciplines of medicine because of their sufficient biocompatibility and meeting of mechanical requirements. However, dense metallic biomaterials represent only an interfacial connection with host tissue, may develop stress shielding which causes ingrowth of the fibrous tissue, and are prone to microbial adhesion and development of biomaterial associated infections. Therefore, development of a new, porous titanium biomaterial is proposed to improve an implant's interconnection with bone, provide better stabilization, and reduce the risk of the loss of the implant. In this review, recent findings in porous titanium biomaterials engineering are discussed, including the structural and strengthening aspects of titanium alloys. The porosity and design of porous structures, as well as the optimization process are also described. An extensive part of this section is dedicated to manufacturing processes. The next section of the review is devoted to osseointegration of porous implants and surface treatment processes, whose purpose are antibacterial activity or local drug delivery. Summarizing the article, some future predictions have been presented.
Oxidation Behavior between 700 and 1300 °C of Refractory TiZrNbHfTa High‐Entropy Alloys Containing Aluminum
Authors: Chang Chia‐Hsiu , Titus Michael S. , Yeh Jien‐Wei
Published: January 2018

Refractory alloys without Cr, Al, and Si additions exhibit very poor high temperature oxidation resistance and thus significantly limit their applications. With an aim to improve the poor oxidation resistance of strong and ductile refractory TiZrNbHfTa high‐entropy alloys (HEAs), this study investigates the effect of Al additions on the oxidation behavior and mechanisms for Al0‐1TiZrNbHfTa HEAs. Higher Al content renders the alloy more resistant to oxidation. The AlTiZrNbHfTa alloy exhibits a mass gain twice of that of conventional Ni‐based alloys at 1100 °C for 1 h, but much less than Nb refractory alloys because an Al‐containing oxide on the surface layer provides a partial barrier against oxidation between 700 and 1100 °C. But, at 1300 °C the Al‐containing alloys exhibit poor oxidation resistance because the less dense oxide layers provide oxygen with an effective diffusional channel and enable oxygen to penetrate the substrate more easily.
Dynamic Poly(3,4‐ethylenedioxythiophene)s Integrate Low Impedance with Redox‐Switchable Biofunction
Authors: Lin Hsing‐An , Zhu Bo , Wu Yu‐Wei , Sekine Jun , Nakao Aiko , Luo Shyh‐Chyang , Yamashita Yoshiro , Yu Hsiao‐Hua
Published: January 2018

To generate the electrical communication, biocompatibility, and controlled cell attachment properties required for advanced bioelectronic technologies, a dynamic poly(3,4‐ethylenedioxythiophene) (PEDOT) film is developed based on a biomimetic approach. The dynamic PEDOT integrates low impedance, nonspecific‐binding resistance, and redox‐responsive characteristics while coupling with cells stably and specifically. The combination of these features ensures stable and efficient electrical communication with cells and promises potentially reduced disruption of complexes in physiological environments due to the material's strong resistance to nonspecific interactions; more significantly, the integration of these features in one material enables the spatiotemporal attachment and detachment of cells on demand without damage to cell viability and neurites after 5 d of electrical stimulation and culturing. The dynamic and biomimetic PEDOT material can be an ideal electronic interface with optimized electrochemical and biological characteristics toward biocompatible and controllable electrocoupling with cells at low impedance.
Micro/Nanomachines and Living Biosystems: From Simple Interactions to Microcyborgs
Authors: Wang Hong , Pumera Martin
Published: January 2018

Miniaturization of machines into the micro/nanoscale is an essential ingredient toward better understanding and control of the microscopic world. As an emerging research area, micro/nanomachines have attracted substantial efforts of researchers from multiple disciplines. Mimicking the biological machines in nature, artificial micro/nanomachines are becoming increasingly sophisticated so that they can serve as useful tools to address problems encountered in the intricate biosystems. This review highlights the recent efforts for and toward application of micro/nanomachines in living biosystems, including microorganisms, biological cells, and human body. With progressive steps toward translating micro/nanomachines research into practice, using these tiny machines to tackle thorny problems in biosystems may not only exist in the Hollywood science fiction film.
Achieving a Record Fill Factor for Silicon–Organic Hybrid Heterojunction Solar Cells by Using a Full‐Area Metal Polymer Nanocomposite Top Electrode
Authors: Zhu Juye , Yang Xi , Yang Zhenhai , Wang Dan , Gao Pingqi , Ye Jichun
Published: January 2018

Carrier collection in conventional n‐type Si (n‐Si)/organic hybrid heterojunction solar cells (HHSCs) is mainly limited by the nonoptimized top grid‐electrode and inadequate work function (WF) of the PH1000‐type poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS). Here, a novel modified metal polymer nanocomposite top electrode (M‐MPNTE) is designed to achieve a full‐area carrier collection in n‐Si/PEDOT:PSS HHSCs. The carrier collection in both lateral and vertical directions is significantly improved by the introduction of an ultrathin Au/MoOx modified layer between 6 nm ultrathin Ag film and AI4083‐type PEDOT:PSS layer. In addition, the carrier separation is boosted by the enhanced built‐in potential owing to a high WF of M‐MPNTE, which also suppresses the carrier recombination at the surface of n‐Si. Due to these collaborative improvements, a record fill factor of 80.21% is obtained, which is even comparable to the best value of the traditional Si‐based solar cells. With the addition of a MoOx antireflective coating layer on top of M‐MPNTE, the short‐circuit current density and open‐circuit voltage are finally increased to 23.13 mA cm−2 and 621.07 mV, respectively, yielding a power conversion efficiency of 10.82%. The finding suggests a novel strategy for the development of highly efficient HHSCs with ideal carrier transport mechanism.
Reconfigurable Swarms of Ferromagnetic Colloids for Enhanced Local Hyperthermia
Authors: Wang Ben , Chan Kai Fung , Yu Jiangfan , Wang Qianqian , Yang Lidong , Chiu Philip Wai Yan , Zhang Li
Published: January 2018

Ferromagnetic particles (FMPs) have attracted a large amount of attention for tumor treatment in recent decades in the form of magnetic hyperthermia and thermoablation therapies. Previous research has commonly focused on the improvement of the specific loss power and the increase in the particle concentration to enhance the heating temperature during hyperthermia. Instead of magnetic hyperthermia with passive particles, here a feasible approach of using reconfigurable swarms of ferromagnetic colloidal particles is reported to realize enhanced local hyperthermia. The concentration of the particle swarm can be tuned up to 500% of the original particle concentration via reversible pattern transformation, i.e., shrinking and swelling. The FMP swarms with a controllable pattern size show their potential for directed energy delivery and offer a new strategy for realizing a highly localized heating effect using a low dose of the active FMPs.
Lithium Tin Sulfide—a High‐Refractive‐Index 2D Material for Humidity‐Responsive Photonic Crystals
Authors: Szendrei‐Temesi Katalin , Sanchez‐Sobrado Olalla , Betzler Sophia B. , Durner Katharina M. , Holzmann Tanja , Lotsch Bettina V.
Published: January 2018

Extending the portfolio of novel stimuli‐responsive, high‐refractive‐index (RI) materials besides titania is key to improve the optical quality and sensing performance of existing photonic devices. Herein, lithium tin sulfide (LTS) nanosheets are introduced as a novel solution processable ultrahigh RI material (n = 2.50), which can be casted into homogeneous thin films using wet‐chemical deposition methods. Owing to its 2D morphology, thin films of LTS nanosheets are able to swell in response to changes of relative humidity. Integration of LTS nanosheets into Bragg stacks (BSs) based on TiO2, SiO2, nanoparticles or H3Sb3P2O14 nanosheets affords multilayer systems with high optical quality at an extremely low device thickness of below 1 µm. Owing to the ultrahigh RI of LTS nanosheets and the high transparency of the thin films, BSs based on porous titania as the low‐RI material are realized for the first time, showing potential application in light‐managing devices. Moreover, the highest RI contrast ever realized in BSs based on SiO2 and LTS nanosheets is reported. Finally, exceptional swelling capability of an all‐nanosheet BS based on LTS and H3Sb3P2O14 nanosheets is demonstrated, which bodes well for a new generation of humidity sensors with extremely high sensitivity.
Complementary Electromagnetic‐Triboelectric Active Sensor for Detecting Multiple Mechanical Triggering
Authors: Wang Peihong , Liu Ruiyuan , Ding Wenbo , Zhang Peng , Pan Lun , Dai Guozhang , Zou Haiyang , Dong Kai , Xu Cheng , Wang Zhong Lin
Published: January 2018

With the fast development of integrated circuit technology and internet of things, sensors with multifunctional characteristics are desperately needed. This work presents an integrated electromagnetic‐triboelectric active sensor (ETAS) for simultaneous detection of multiple mechanical triggering signals. The good combination of a contact‐separation mode triboelectric nanogenerator (TENG) and an electromagnetic generator (EMG) realizes the complement of their individual advantages. The theoretical calculation and analysis of EMG and TENG are performed to understand the relationship between their output and the external mechanical signals. The experimental results show that the output voltage of TENG part is suitable to detect the magnitude of the external triggering force with a sensitivity of about 2.01 V N−1. Meanwhile, the output current of EMG part is more appropriate to reflect the triggering velocity and the sensitivity is about 4.3 mA (m s−1)−1. Moreover, both the TENG part and the EMG part exhibit good stabilities after more than 20 000 cycles of force loading and unloading. One ETAS that can record the typing behavior of the finger precisely is demonstrated. In addition, the TENG part can harvest the mechanical energy during typing for possible powering of tiny electronics. This ETAS has promising applications in complex human–machine interface, personal identification, and security system.
Graphene Microstrip Patch Ultrawide Band Antennas for THz Communications
Authors: Dashti Mojtaba , Carey J. David
Published: January 2018

Future generation local communication systems will need to employ THz frequency bands capable of transferring sizable amounts of data. Current THz technology via electrical excitation is limited by the upper limits of device cutoff frequencies and by the lower limits of optical transitions in quantum confined structures. Current metallic THz antennas require high power to overcome scattering losses and tend to have low antenna efficiency. It is shown here via calculation and simulation that graphene can sustain electromagnetic propagation at THz frequencies via engineering the intra‐ and interband contributions to the dynamical conductivity to produce a variable surface impedance microstrip antenna with a several hundred GHz bandwidth. The optimization of a circular graphene microstrip patch antenna on silicon with an optimized return loss of −26 dB, a −10 dB bandwidth of 504 GHz, and an antenna efficiency of −3.4 dB operating at a frequency of 2 THz is reported. An improved antenna efficiency of −0.36 dB can be found at 3.5 THz but is accompanied by a lower bandwidth of about 200 GHz. Such large bandwidths and antenna efficiencies offer significant hope for graphene‐based flexible directional antennas that can be employed for future THz local device‐to‐device communications.
Exciton‐Adjustable Interlayers for High Efficiency, Low Efficiency Roll‐Off, and Lifetime Improved Warm White Organic Light‐Emitting Diodes (WOLEDs) Based on a Delayed Fluorescence Assistant Host
Authors: Wang Zhiheng , Li Xiang‐Long , Ma Zerui , Cai Xinyi , Cai Chengsong , Su Shi‐Jian
Published: January 2018

Recently, a new route to achieve 100% internal quantum efficiency white organic light‐emitting diodes (WOLEDs) is proposed by utilizing noble‐metal‐free thermally activated delayed fluorescence (TADF) emitters due to the radiative contributions of triplet excitons by effective reverse intersystem crossing. However, a systematic understanding of their reliability and internal degradation mechanisms is still deficient. Here, it demonstrates high performance and operational stable purely organic fluorescent WOLEDs consisting of a TADF assistant host via a strategic exciton management by multi‐interlayers. By introducing such interlayers, carrier recombination zone could be controlled to suppress the generally unavoidable quenching of long‐range triplet excitons, successfully achieving remarkable external quantum efficiency of 15.1%, maximum power efficiency of 48.9 lm W−1, and extended LT50 lifetime (time to 50% of initial luminance of 1000 cd m−2) exceeding 2000 h. To this knowledge, this is the first pioneering work for realizing high efficiency, low efficiency roll‐off, and operational stable WOLEDs based on a TADF assistant host. The current findings also indicate that broadening the carrier recombination region in both interlayers and yellow emitting layer as well as restraining exciplex quenching at carrier blocking interface make significant roles on reduced efficiency roll‐off and enhanced operational lifetime.
Physical Properties of Implanted Porous Bioscaffolds Regulate Skin Repair: Focusing on Mechanical and Structural Features
Authors: Jiang Shumeng , Li Sabrina Cloud , Huang Chenyu , Chan Barbara Pui , Du Yanan
Published: January 2018

Porous bioscaffolds are applied to facilitate skin repair since the early 1990s, but a perfect regeneration outcome has yet to be achieved. Until now, most efforts have focused on modulating the chemical properties of bioscaffolds, while physical properties are traditionally overlooked. Recent advances in mechanobiology and mechanotherapy have highlighted the importance of biomaterials' physical properties in the regulation of cellular behaviors and regenerative processes. In skin repair, the mechanical and structural features of porous bioscaffolds are two major physical properties that determine therapeutic efficacy. Here, first an overview of natural skin repair with an emphasis on the major biophysically sensitive cell types involved in this multistage process is provided, followed by an introduction of the four roles of bioscaffolds as skin implants. Then, how the mechanical and structural features of bioscaffolds influence these four roles is discussed. The mechanical and structural features of porous bioscaffolds should be tailored to balance the acceleration of wound closure and functional improvements of the repaired skin. This study emphasizes that decoupling and precise control of the mechanical and structural features of bioscaffolds are significant aspects that should be considered in future biomaterial optimization, which can build a foundation to ultimately achieve perfect skin regeneration outcomes.
A Multifunctional Micellar Nanoplatform with pH‐Triggered Cell Penetration and Nuclear Targeting for Effective Cancer Therapy and Inhibition to Lung Metastasis
Authors: Jing Yuting , Xiong Xiang , Ming Yang , Zhao Jingya , Guo Xing , Yang Guang , Zhou Shaobing
Published: January 2018

The enhancement of cellular internalization and subsequent achievement of a nuclear targeting of nanocarriers play an important role in maximizing the therapeutic potency and minimizing the side effects of encapsulated drugs. Herein, a multifunctional micellar nanoplatform simultaneously with high cell penetration and nuclear targeting through pH‐triggered surface charge reversal is presented. The miscellar system is constructed from poly(ethylene glycol)‐poly(ε‐caprolactone) with 2,3‐dimethylmaleic anhydride‐Tat decoration (PECL/DA‐Tat). DA groups are used to mask the positive charge of Tat to prolong blood circulation of the nanocarriers. In the mildly acidic environment of tumor tissue, the system exhibits ultrasensitive negative to positive charge reversal, facilitating the cell internalization and subsequent nuclear targeting. The chemotherapeutic 10‐hydroxycamptothecin conjugated to methoxy polyethylene glycol, which is loaded in this micelle, obviously enhances cytotoxicity against tumor cells. The in vivo therapy in mice bearing 4T1 breast tumor reveals that the system has a significant enhancement of both the endocytosis and nuclear enrichment, showing a highly effective antitumor efficacy and inhibition to lung metastasis.
Designing 3D Biological Surfaces via the Breath‐Figure Method
Authors: Chen Shuangshuang , Gao Su , Jing Jiange , Lu Qinghua
Published: January 2018

The fabrication of biointerfaces that mimic cellular physiological environments is critical to understanding cell behaviors in vitro and for the design of tissue engineering. Breath figure is a self‐assemble method that uses water droplets condensed from moisture as template and ends up with a highly ordered hexagonal pore array; this approach is used to fabricate various biological substrates. This progress report provides an overview of strategies to achieve topographical modifications and chemical‐patterned arrays, such as modulation of the pore size, shape and selective decoration of the honeycomb holes. Using recent results in the biological fields, potential future applications and developments of honeycomb structures are commented upon.
Superhydrophobic/Superhydrophilic Janus Fabrics Reducing Blood Loss
Authors: Zhu Tang , Wu Junrong , Zhao Ning , Cai Chao , Qian Zhenchao , Si Fangfang , Luo Heng , Guo Jing , Lai Xuan , Shao Longquan , Xu Jian
Published: January 2018

Hemostatic fabrics are most commonly used in baseline emergency treatment; however, the unnecessary blood loss due to the excessive blood absorption by traditional superhydrophilic fabrics is overlooked. Herein, for the first time, superhydrophobic/superhydrophilic Janus fabrics (superhydrophobic on one side and superhydrophilic on the other) are proposed: the superhydrophilic part absorbs water in the blood to expedite the clotting while the superhydrophobic part prevents blood from further permeating. Compared with the common counterparts, effective bleeding control with reducing blood loss more than 50% can be achieved while the breathability largely remain by using Janus fabrics. The proposed prototypes can even prolong the survival time in the rat model with serious bleeding. This strategy for reducing blood loss via simply tuning wettability is promising for the practical applications.
Natural Humic‐Acid‐Based Phototheranostic Agent
Authors: Miao Zhao‐Hua , Li Kai , Liu Pei‐Ying , Li Zhenglin , Yang Huanjie , Zhao Qingliang , Chang Manli , Yang Qingzhu , Zhen Liang , Xu Cheng‐Yan
Published: January 2018

Humic acids, a major constituent of natural organic carbon resources, are naturally formed through the microbial biodegradation of animal and plant residues. Due to numerous physiologically active groups (phenol, carboxyl, and quinone), the biomedical applications of humic acid have been already investigated across different cultures for several centuries or even longer. In this work, sodium humate, the sodium salt of humic acid, is explored as phototheranostic agent for light‐induced photoacoustic imaging and photothermal therapy based on intrinsic absorption in the near‐infrared region. The purified colloidal sodium humate exhibits a high photothermal conversion efficiency up to 76.3%, much higher than that of the majority of state‐of‐the‐art photothermal agents including gold nanorods, Cu9S5 nanoparticles, antimonene quantum dots, and black phosphorus quantum dots, leading to obvious photoacoustic enhancement in vitro and in vivo. Besides, highly effective photothermal ablation of HeLa tumor is achieved through intratumoral injection. Impressively, sodium humate reveals ultralow toxicity at the cellular and animal levels. This work promises the great potential of humic acids as light‐mediated theranostic agents, thus expanding the application scope of traditional humic acids in biomedical field.
Microfluidic Tumor–Vascular Model to Study Breast Cancer Cell Invasion and Intravasation
Authors: Nagaraju Supriya , Truong Danh , Mouneimne Ghassan , Nikkhah Mehdi
Published: January 2018

Cancer is a major leading cause of disease‐related death in the world. The severe impact of cancer can be attributed to poor understanding of the mechanisms involved in earliest steps of the metastatic cascade, specifically invasion into the surrounding stroma and intravasation into the blood capillaries. However, conducting integrated biological studies of invasion and intravasation have been challenging, within in vivo models and traditional in vitro assay, due to difficulties in establishing a precise tumor microenvironment. To that end, in this work, a novel 3D microfluidic platform comprised of concentric three‐layer cell‐laden hydrogels for simultaneous investigation of breast cancer cell invasion and intravasation as well as vasculature maturation influenced by tumor–vascular crosstalk is developed. It was demonstrated that the presence of spontaneously formed vasculature enhance MDA‐MB‐231 invasion into the 3D stroma. Following invasion, cancer cells are visualized intravasating into the outer vasculature. Additionally, invading cancer cells significantly reduce vessel diameter while increasing permeability, consistent with previous in vivo studies. Major signaling cytokines involved in tumor–vascular crosstalk that govern cancer cell invasion and intravasation are further identified. Taken together, this platform will enable unique insights of critical biological events within the metastatic cascade, with significant potential for developing efficient cancer therapeutics.
Polymer‐Passivated Inorganic Cesium Lead Mixed‐Halide Perovskites for Stable and Efficient Solar Cells with High Open‐Circuit Voltage over 1.3 V
Authors: Zeng Qingsen , Zhang Xiaoyu , Feng Xiaolei , Lu Siyu , Chen Zhaolai , Yong Xue , Redfern Simon A. T. , Wei Haotong , Wang Haiyu , Shen Huaizhong , Zhang Wei , Zheng Weitao , Zhang Hao , Tse John S. , Yang Bai
Published: January 2018

Cesium‐based trihalide perovskites have been demonstrated as promising light absorbers for photovoltaic applications due to their superb composition stability. However, the large energy losses (Eloss) observed in inorganic perovskite solar cells has become a major hindrance impairing the ultimate efficiency. Here, an effective and reproducible method of modifying the interface between a CsPbI2Br absorber and polythiophene hole‐acceptor to minimize the Eloss is reported. It is demonstrated that polythiophene, deposited on the top of CsPbI2Br, can significantly reduce electron‐hole recombination within the perovskite, which is due to the electronic passivation of surface defect states. In addition, the interfacial properties are improved by a simple annealing process, leading to significantly reduced energy disorder in polythiophene and enhanced hole‐injection into the hole‐acceptor. Consequently, one of the highest power conversion efficiency (PCE) of 12.02% from a reverse scan in inorganic mixed‐halide perovskite solar cells is obtained. Modifying the perovskite films with annealing polythiophene enables an open‐circuit voltage (VOC) of up to 1.32 V and Eloss of down to 0.5 eV, which both are the optimal values reported among cesium‐lead mixed‐halide perovskite solar cells to date. This method provides a new route to further improve the efficiency of perovskite solar cells by minimizing the Eloss.
Preparation of High‐Percentage 1T‐Phase Transition Metal Dichalcogenide Nanodots for Electrochemical Hydrogen Evolution
Authors: Tan Chaoliang , Luo Zhimin , Chaturvedi Apoorva , Cai Yongqing , Du Yonghua , Gong Yue , Huang Ying , Lai Zhuangchai , Zhang Xiao , Zheng Lirong , Qi Xiaoying , Goh Min Hao , Wang Jie , Han Shikui , Wu Xue‐Jun , Gu Lin , Kloc Christian , Zhang Hua
Published: January 2018

Nanostructured transition metal dichalcogenides (TMDs) are proven to be efficient and robust earth‐abundant electrocatalysts to potentially replace precious platinum‐based catalysts for the hydrogen evolution reaction (HER). However, the catalytic efficiency of reported TMD catalysts is still limited by their low‐density active sites, low conductivity, and/or uncleaned surface. Herein, a general and facile method is reported for high‐yield, large‐scale production of water‐dispersed, ultrasmall‐sized, high‐percentage 1T‐phase, single‐layer TMD nanodots with high‐density active edge sites and clean surface, including MoS2, WS2, MoSe2, Mo0.5W0.5S2, and MoSSe, which exhibit much enhanced electrochemical HER performances as compared to their corresponding nanosheets. Impressively, the obtained MoSSe nanodots achieve a low overpotential of −140 mV at current density of 10 mA cm−2, a Tafel slope of 40 mV dec−1, and excellent long‐term durability. The experimental and theoretical results suggest that the excellent catalytic activity of MoSSe nanodots is attributed to the high‐density active edge sites, high‐percentage metallic 1T phase, alloying effect and basal‐plane Se‐vacancy. This work provides a universal and effective way toward the synthesis of TMD nanostructures with abundant active sites for electrocatalysis, which can also be used for other applications such as batteries, sensors, and bioimaging.
Saturable Absorption in 2D Ti3C2 MXene Thin Films for Passive Photonic Diodes
Authors: Dong Yongchang , Chertopalov Sergii , Maleski Kathleen , Anasori Babak , Hu Longyu , Bhattacharya Sriparna , Rao Apparao M. , Gogotsi Yury , Mochalin Vadym N. , Podila Ramakrishna
Published: January 2018

MXenes comprise a new class of 2D transition metal carbides, nitrides, and carbonitrides that exhibit unique light–matter interactions. Recently, 2D Ti3CNTx (Tx represents functional groups such as OH and F) was found to exhibit nonlinear saturable absorption (SA) or increased transmittance at higher light fluences, which is useful for mode locking in fiber‐based femtosecond lasers. However, the fundamental origin and thickness dependence of SA behavior in MXenes remain to be understood. 2D Ti3C2Tx thin films of different thicknesses are fabricated using an interfacial film formation technique to systematically study their nonlinear optical properties. Using the open aperture Z‐scan method, it is found that the SA behavior in Ti3C2Tx MXene arises from plasmon‐induced increase in the ground state absorption at photon energies above the threshold for free carrier oscillations. The saturation fluence and modulation depth of Ti3C2Tx MXene is observed to be dependent on the film thickness. Unlike other 2D materials, Ti3C2Tx is found to show higher threshold for light‐induced damage with up to 50% increase in nonlinear transmittance. Lastly, building on the SA behavior of Ti3C2Tx MXenes, a Ti3C2Tx MXene‐based photonic diode that breaks time‐reversal symmetry to achieve nonreciprocal transmission of nanosecond laser pulses is demonstrated.
A Light Harvesting, Self‐Powered Monolith Tactile Sensor Based on Electric Field Induced Effects in MAPbI3 Perovskite
Authors: Saraf Rohit , Pu Long , Maheshwari Vivek
Published: January 2018

Organolead trihalide perovskite MAPbI3 shows a distinctive combination of properties such as being ferroelectric and semiconducting, with ion migration effects under poling by electric fields. The combination of its ferroelectric and semiconducting nature is used to make a light harvesting, self‐powered tactile sensor. This sensor interfaces ZnO nanosheets as a pressure‐sensitive drain on the MAPbI3 film and once poled is operational for at least 72 h with just light illumination. The sensor is monolithic in structure, has linear response till 76 kPa, and is able to operate continuously as the energy harvesting mechanism is decoupled from its pressure sensing mechanism. It has a sensitivity of 0.57 kPa−1, which can be modulated by the strength of the poling field. The understanding of these effects in perovskite materials and their application in power source free devices are of significance to a wide array of fields where these materials are being researched and applied.
Uniform Lithium Nucleation/Growth Induced by Lightweight Nitrogen‐Doped Graphitic Carbon Foams for High‐Performance Lithium Metal Anodes
Authors: Liu Lin , Yin Ya‐Xia , Li Jin‐Yi , Wang Shu‐Hua , Guo Yu‐Guo , Wan Li‐Jun
Published: January 2018

The lithium metal anode has attracted soaring attention as an ideal battery anode. Unfortunately, nonuniform Li nucleation results in uncontrollable growth of dendritic Li, which incurs serious safety issues and poor electrochemical performance, hindering its practical applications. Herein, this study shows that uniform Li nucleation/growth can be induced by an ultralight 3D current collector consisting of in situ nitrogen‐doped graphitic carbon foams (NGCFs) to realize suppressing dendritic Li growth at the nucleating stage. The N‐containing functional groups guide homogenous growth of Li nucleus nanoparticles and the initial Li nucleus seed layer regulates the following well‐distributed Li growth. Benefiting from such favorable Li growth behavior, superior electrochemical performance can be achieved as evidenced by the high Coulombic efficiency (≈99.6% for 300 cycles), large capacity (10 mA h cm−2, 3140 mA h g−1NGCF‐Li), and ultralong lifespan (>1200 h) together with low overpotential (<25 mV at 3 mA cm−2); even under a high current density up to 10 mA cm−2, it still displays low overpotential of 62 mV.
Dynamic Coordination of Eu–Iminodiacetate to Control Fluorochromic Response of Polymer Hydrogels to Multistimuli
Authors: Weng Gengsheng , Thanneeru Srinivas , He Jie
Published: January 2018

New fluorochromic materials that reversibly change their emission properties in response to their environment are of interest for the development of sensors and light‐emitting materials. A new design of Eu‐containing polymer hydrogels showing fast self‐healing and tunable fluorochromic properties in response to five different stimuli, including pH, temperature, metal ions, sonication, and force, is reported. The polymer hydrogels are fabricated using Eu–iminodiacetate (IDA) coordination in a hydrophilic poly(N,N‐dimethylacrylamide) matrix. Dynamic metal–ligand coordination allows reversible formation and disruption of hydrogel networks under various stimuli which makes hydrogels self‐healable and injectable. Such hydrogels show interesting switchable ON/OFF luminescence along with the sol–gel transition through the reversible formation and dissociation of Eu–IDA complexes upon various stimuli. It is demonstrated that Eu‐containing hydrogels display fast and reversible mechanochromic response as well in hydrogels having interpenetrating polymer network. Those multistimuli responsive fluorochromic hydrogels illustrate a new pathway to make smart optical materials, particularly for biological sensors where multistimuli response is required.
Surface Modification of V–VI Semiconductors Using Exchange Reactions within ALD Half‐Cycles
Authors: Wiegand Christoph W. , Zierold Robert , Faust René , Pohl Darius , Thomas Andy , Rellinghaus Bernd , Nielsch Kornelius
Published: January 2018

The behaviors of tellurium and selenium atomic layer deposition vapor precursors, namely, Te(SiEt3)2 and Se(SiEt3)2, exposed to different V–VI semiconductor surfaces are reported. The interactions of the precursors with the substrates are monitored in situ with a quartz crystal microbalance (QCM) setup. Specifically, both the utilized metal–organic precursors interact with chalcogenide surfaces but differ in their reaction behaviors. Indeed, exchanged Te diffuses into the selenium‐containing substrate, whereas Se only exchanges with the top surface of the substrate. Transmission electron micrsocopy (TEM) and energy‐dispersive X‐ray spectroscopy (EDX/EDXS) analysis of the topological insulating nanowires reveals the single precursor interactions, which support the QCM data analysis, and provides insight into the morphological and crystalline structures of the altered substrates.
Bioinspired Fabrication of Bi/Tridirectionally Anisotropic Sliding Superhydrophobic PDMS Surfaces by Femtosecond Laser
Authors: Fang Yao , Yong Jiale , Chen Feng , Huo Jinglan , Yang Qing , Zhang Jingzhou , Hou Xun
Published: January 2018

Precisely arranged multiscale microstructures in living systems provide inspirations for the fabrication of artificial advanced materials and devices. Recently, uni‐bioinspired surfaces with anisotropic wettability are built for various applications. Here, a kind of bi‐bioinspired (rice leaf and butterfly wing) tridirectionally anisotropic sliding superhydrophobic surface for the first time is reported. First, a microgroove array structured polydimethylsiloxane surface is constructed by selective femtosecond laser ablation. The as‐prepared surface shows bidirectional anisotropy which can be easily tuned by the width (L) and the depth of the microgrooves. A “steps” structure is further introduced into the microgrooves. Interestingly, tridirectionally anisotropic sliding superhydrophobicity that combined the rice‐leaf‐like and butterfly‐wing‐like anisotropy is achieved on such surface. The tridirectional anisotropy is demonstrated to result from the directional “steps” structures and the uneven distribution of rough structures. The bi/tridirectionally anisotropic sliding property will provide a fresh cognition of anisotropic wettability for researchers and have enormous potential applications in smart microfluidic systems.
A High‐Performance Self‐Powered Photodetector Based on Monolayer MoS2/Perovskite Heterostructures
Authors: Bai Fan , Qi Junjie , Li Feng , Fang Youyin , Han Weipeng , Wu Hualin , Zhang Yue
Published: January 2018

Here, it is first reported that a self‐powered photodetector based on a MoS2/CH3NH3PbI3 vertical type heterojunction, which has responsivity of 60 mAW−1 and response/recovery time of 2149/899 ms. Under bias, it exhibits a photoswitching ratio exceeding 1522, fast response/recovery time of 205/206 ms, and high photoresponsivity of 68.11 AW−1. The optoelectronic performances of the photodetector are closely related to the type of the MoS2/CH3NH3PbI3 heterojunction, which acts as a hole (electron) transport field and can effectively decrease the recombination of holes and electrons. Additionally, the MoS2/CH3NH3PbI3 planar type heterojunction is also built to compare with the vertical type in optoelectronics behavior. Due to the existence of internal field, the properties of vertical type photodetector are better than those of the planar type which also presents good performance with on/off ratio up to 1476, photoresponsivity of 28 AW−1, and response rate of 356/204 ms. These results pave a new way to form an ultrahigh performance MoS2/CH3NH3PbI3 heterojunction, hold the promise for construction of a self‐powered photodetector, and develop promising atomically thin MoS2 heterostructure device for photovoltaic and optoelectronic applications.