bluuebunny/crossref_metadata_2025 huggingface dataset:
New Formula for Fragment Velocity in the Aiming Direction of an Asymmetrically Initiated Warhead
Authors: Li Yuan , Li Xiaogang , Xiong Shihui , Wen Yuquan
Published: March 2018

Fragment velocity is an important parameter for fragmentation warheads, but for an asymmetrically initiated warhead, formulas for calculating the fragment velocity in the aiming direction are rare. In this work, new formulas for calculating fragment velocities in the aiming direction and the initiation side of an asymmetrically initiated warhead were established by taking the long element from the warhead section and applying one‐dimensional gas dynamics. Accounting for the assumptions made during the formulas establishing, three experimentally verified warheads modelling of different charge ratios were used to verify the formulas. It is found that the velocity ratios of the modelling to the formulas’ calculations of different warheads are very similar. Hence the fitted curves for the velocity ratios versus the warhead charge ratios were used as correction factors for the established formulas. Finally experiments were designed and conducted to validate the revised formulas, which shows acceptable relative errors of 2.8 % and 9.9 %, better than already existing formulas. The established formulas could be a good reference for the damage evaluation of aimable warheads and for fragment velocity distribution research.
Effect of tadalafil on chronic pelvic pain and prostatic inflammation in a rat model of experimental autoimmune prostatitis
Authors: Okamoto Ken , Kurita Maki , Yamaguchi Hiroshi , Numakura Yuki , Oka Michiko
Published: March 2018

Background

Experimental autoimmune prostatitis (EAP) shares important clinical features with clinical chronic prostatitis/chronic pelvic pain. We investigated the effect of tadalafil on pelvic pain and prostatic inflammation in a rat EAP model.

Methods

EAP was induced in rats by intradermal injection of rat prostate antigen and complete Freund's adjuvant on days 0 and 28. Rats were treated with tadalafil (2 mg/kg, p.o.; EAP‐tadalafil) or vehicle (EAP‐vehicle) once daily from day 0, while sham‐operated animals were treated with vehicle only (Sham). Tactile allodynia was measured on days 28, 35, and 42 by applying von Frey filaments to the lower abdomen as an index of pelvic pain. On day 42, the plasma immunoglobulin G (IgG) concentration and the testosterone/estradiol ratio were measured and histopathological analysis of the prostate was performed.

Results

Tactile allodynia in the pelvic region was observed on days 28, 35, and 42 after EAP induction. The tactile allodynia observed on day 42 was significantly reduced by repeated treatment with tadalafil. Plasma IgG concentrations increased after EAP induction but the increase was not changed by tadalafil treatment. Prostate tissues were characterized by epithelial necrosis, infiltration of neutrophils and/or lymphocytes to acini and stroma, and fibrosis, in addition to a high stroma‐to‐epithelium ratio. Tadalafil treatment significantly suppressed the severity of the lesions.

Conclusions

EAP rats developed pelvic pain, prostatic inflammation and increased plasma IgG concentrations. Tadalafil inhibited the chronic pelvic pain and prostatic inflammation, suggesting that its anti‐inflammatory action may contribute to its blocking of pain development in the EAP model.
Interaction of spirodiclofen with insecticides for the control of Brevipalpus yothersi in citrus
Authors: Della Vechia Jaqueline F , Ferreira Marcelo C , Andrade Daniel J
Published: March 2018

BACKGROUND

The mite Brevipalpus yothersi (Acari: Tenuipalpidae) is of great importance in citriculture because it is a vector of the disease citrus leprosis. The frequency of application of a combination of pesticides has increased because of an increase in the occurrence of economically important pests of citrus. However, the combined effect of acaricide and other insecticides targeting B. yothersi is unknown. The objective of this study was to evaluate the effect of a combination of spirodiclofen and other insecticides on the control of B. yothersi.

RESULTS

Analysis using spirodiclofen alone resulted in 97.22% efficiency in the control of B. yothersi on day 7 after application. A combination of spirodiclofen with either phosmet or imidacloprid resulted in 55% and 59% efficiency, respectively. A reduction in the efficiency of mite control by up to 42% was observed when the mites were exposed to a combination of acaricide with other insecticides.

CONCLUSIONS

Application of a combination of spirodiclofen with phosmet or imidacloprid compromises the efficiency of acaricide in the control of B. yothersi. © 2018 Society of Chemical Industry
Low‐Temperature Fabrication and Performance of Polycrystalline CuI Films as Transparent p‐Type Semiconductors
Authors: Yamada Naoomi , Kondo Yuumi , Ino Ruichiro
Published: March 2018

Transparent p‐type polycrystalline CuI films with high hole mobility are produced by solid iodination of Cu3N precursor layers and subsequent heat treatment at 120 °C. The hole mobility reached 20 cm2 V−1 s−1 in the CuI films fabricated on both glass and polyethylene terephthalate substrates. Furthermore, transparent p–n diodes with sufficiently high rectification ratio (6 × 106) and ideality factor (1.6) are successfully fabricated by employing a heterojunction of p‐type CuI and n‐type amorphous In–Ga–Zn–O (a‐IGZO) layers. The CuI/a‐IGZO heterojunction exhibits the photovoltaic effect, with a short‐circuit current of 0.33 µA and an open‐circuit voltage of 10 mV under UV illumination at a wavelength of 365 nm and intensity of 1.9 mW cm−2. The photoresponse at zero bias is sufficiently quick, and thus, the photovoltaic properties of the CuI/a‐IGZO diodes rendere them potential candidates for visible‐light‐blind and self‐powered UV photodetectors. These findings suggest that CuI is an excellent transparent p‐type semiconductor that can be fabricated at low temperature.
Structure and Thermal Stability of Stilbenedithiol SAMs on Au(111)
Authors: Völkner Johannes , Bashir Asif , Parak Wolfgang J. , Witte Gregor
Published: March 2018

Self‐assembling monolayers (SAMs) of dithiols play an important role as bivalent linker layer in applications such as photoelectrochemical sensors. However, their formation processes and film structure are not fully understood yet. Herein, a SAM of aromatic trans‐stilbenedithiol (StDT) on Au(111) surfaces is investigated. Using complementary characterization techniques the dependence of the film quality on preparation parameters, such as used solvent, temperature and ambient conditions during and subsequent to preparation is investigated. Furthermore, a remarkably high thermal stability is found which is ascribed to disulfide bridging between the endgroups of the individual molecules.
Kinetics of Silver Photodiffusion Into Amorphous Ge20S80 Films: Case of Pre‐Reaction
Authors: Sakaguchi Yoshifumi , Hanashima Takayasu , Aoki Hiroyuki , Asaoka Hidehito , Ahmed Simon Al‐Amin , Mitkova Maria
Published: March 2018

Silver photodiffusion into amorphous chalcogenide has attracted much attention because of its potential applications for example in memory devices. For its development, it is important to know how Ag ions diffuse in chalcogenide layers upon light exposure. In this paper, the photo‐induced effect on “pre‐reacted” films before light exposure, originating from Ag/Ge20S80/Si substrate and Ge20S80/Ag/Si substrate is investigated, using neutron reflectivity, X‐ray reflectivity, and X‐ray diffraction. Two types of “pre‐reacted” films according to the original stacking order are obtained. In both cases, a pure Ag layer almost disappeared, and there is a small amount of monoclinic Ag2S. The reaction time for the photodiffusion is shorter, in both cases, than that in Ag/Ge20S80 with a pure Ag layer, indicating a different reaction process. After prolonged light exposure, a uniform amorphous reaction layer is produced in the films originating from the Ag/Ge20S80/Si substrate, while both an amorphous reaction product and the Ag2S fragments exist in the films originating from Ge20S80/Ag/Si substrate. The mechanism of the specific photo‐reaction is discussed in terms of the role of the Ag2S fragments.
Monolayer–Trilayer Lateral Heterostructure Based Antimonene Field Effect Transistor: Better Contact and High On/Off Ratios
Authors: Chen Jianyong , Yang Zhixiong , Zhou Wenzhe , Zou Hui , Li Mingjun , Ouyang Fangping
Published: March 2018

Inspired by the unique character of the semiconductor‐to‐metal transition from monolayer to trilayer antimonene, we built a monolayer–trilayer lateral heterostructure based field effect transistor (FET). Low tunneling barrier and Schottky barrier are achieved with trilayer antimonene electrodes compared with promising two‐dimensional contact material graphene and metal aluminum. Device performance is calculated accurately using the density functional theory (DFT) and nonequilibrium Green's functions (NEGF). The on/off ratio is 4.87 × 108 with the gate length 10.0 nm. Even if the gate length decreases to 5.0 nm, the on/off ratio is still as high as 1.06 × 106. The lowest power supply voltage (Vdd = 0.76 V) at Vds = 0.6 V to switch “on” and “off” is very close to the requirement of 0.72 V. In addition, the on‐current can be enhanced by a factor of six and on/off ratio is simultaneously lifted up through hydrogen passivation, which offers a route to further optimize the device performance. Low off‐current and high on/off current ratio along with high air stability make the monolayer–trilayer lateral heterostructure based antimonene FET a potential candidate for future low power device applications.
Chemical and absorption signatures of Xiao Chai Hu Tang
Authors: Du Ting , Zeng Min , Chen Li , Cao Zheng , Cai Hua , Yang Guangde
Published: March 2018

Rationale

Xiao Chai Hu Tang (XCHT, Sho‐saiko‐to in Japanese) is a well‐known medicine formula that has been used in Asia for centuries. However, the quality control and the absorption of XCHT components are the major remaining concerns. The study aimed to develop a sensitive and robust method to characterize the chemical components in XCHT and evaluate their absorptions.

Methods

Ultra‐high‐pressure liquid chromatography coupled with electrospray ionization quadrupole time‐of‐flight mass spectrometry (UHPLC/ESI‐QTOF‐MS/MS) was used to identify the compounds in XCHT. The Caco‐2 cell culture model was employed to determine the absorption of the identified components.

Results

The results showed that 109 compounds were identified including organic acids, flavonoids, saikosaponins, ginsenosides, licoricesaponins and gingerols. The absorption study showed that among those identified, 33 compounds have decent absorption permerbilities ranging from 1.46 ± 0.24 × 10−7 to 3.10 ± 0.61 × 10−5 cm/s. These compounds were classified as classes II and IV in the biopharmaceutical classification system (BCS).

Conclusions

These identified compounds could be used to characterize the quality of XCHT and those absorbed compounds with decent permreabiliteis are the potential active components in XCHT. Future pharmacodynamics studies should focus on these absorbed compounds.
Development of a multi‐functional concurrent assay using weak cation‐exchange solid‐phase extraction (WCX‐SPE) and reconstitution with a diluted sample aliquot for anti‐doping analysis
Authors: Kim Yongseok , Jeon Mijin , Min Hophil , Son Junghyun , Lee Jaeick , Kwon Oh‐Seung , Moon Myeong Hee , Kim Ki Hun
Published: March 2018

Rationale

In addition to the development of adequate screening methods for multiple compounds, the World Anti‐Doping Agency (WADA) requires anti‐doping laboratories to analyze prohibited substances and their metabolites from various classes. This task presents a difficult challenge for all agencies and interests involved in the field of doping control.

Methods

A screening method is reported in which hybrid sample preparation was performed using a combination of weak cation‐exchange solid‐phase extraction (WCX‐SPE) and the ‘Dilute and Shoot’ strategy in order to take advantage of both the methodologies. Target substances were extracted using a WCX cartridge and reconstituted with a diluted sample aliquot that included 20% of an untreated urine sample. The target substances were further analyzed by high‐performance liquid chromatography/triple quadrupole mass spectrometry (LC/MS).

Results

The SPE procedure was optimized using a cartridge‐washing step, elution conditions, and elution volume. The cartridge‐washing step, which was performed using 10% methanol, improved the overall recovery of target substances. Since the recovery was observed to vary according to the pH of the eluting solution, we applied an elution step using both an acid and a basic organic solvent to achieve complementary recovery. Reconstitution of the diluted aliquot sample was performed to recover the polar substances.

Conclusions

The method was validated and applied to real samples in accordance with the external quality assessment scheme of WADA and to the previously reported samples that had provided positive test results. This novel method using hybrid sample preparation and LC/MS could be useful to screen multiple classes of the 264 targeted substances in anti‐doping analysis.
Towards robot‐assisted anchor deployment in beating‐heart mitral valve surgery
Authors: Cheng Lingbo , Sharifi Mojtaba , Tavakoli Mahdi
Published: March 2018

Background

Beating‐heart intracardiac surgery promises significant benefits for patients compared with cardiopulmonary bypass based procedures. However, the fast motions of the heart introduce serious challenges for surgeons.

Methods

In this work, a new impedance‐controlled master–slave telerobotic system is developed to help perform anchor deployment for mitral valve annuloplasty under the guidance of live ultrasound images of the heart. The proposed bilateral teleoperation system can both reflect the non‐oscillatory portion of slave–heart tissue interaction force on the surgeon's hand as haptic feedback and implement rapid compensation for the beating heart's motion. The surgical task involves performing anchor deployment on a simulated moving heart tissue to evaluate the effectiveness of the proposed strategy for safely interacting with a moving organ.

Results and Conclusions

The results obtained show that the telerobotic system increases the success rate of anchor deployment by 100% and reduces the excess force application rate by 70% compared with manual attempts.
Human herpesvirus portal proteins: Structure, function, and antiviral prospects
Authors: Kornfeind Ellyn M. , Visalli Robert J.
Published: March 2018

Herpesviruses (Herpesvirales) and tailed bacteriophages (Caudovirales) package their dsDNA genomes through an evolutionarily conserved mechanism. Much is known about the biochemistry and structural biology of phage portal proteins and the DNA encapsidation (viral genome cleavage and packaging) process. Although not at the same level of detail, studies on HSV‐1, CMV, VZV, and HHV‐8 have revealed important information on the function and structure of herpesvirus portal proteins. During dsDNA phage and herpesviral genome replication, concatamers of viral dsDNA are cleaved into single length units by a virus‐encoded terminase and packaged into preformed procapsids through a channel located at a single capsid vertex (portal). Oligomeric portals are formed by the interaction of identical portal protein monomers. Comparing portal protein primary aa sequences between phage and herpesviruses reveals little to no sequence similarity. In contrast, the secondary and tertiary structures of known portals are remarkable. In all cases, function is highly conserved in that portals are essential for DNA packaging and also play a role in releasing viral genomic DNA during infection. Preclinical studies have described small molecules that target the HSV‐1 and VZV portals and prevent viral replication by inhibiting encapsidation. This review summarizes what is known concerning the structure and function of herpesvirus portal proteins primarily based on their conserved bacteriophage counterparts and the potential to develop novel portal‐specific DNA encapsidation inhibitors.
Autonomous legged hill ascent
Authors: Ilhan B. Deniz , Johnson Aaron M. , Koditschek D. E.
Published: March 2018

This paper reports on an autonomous ascent by a legged robotic platform in outdoor forested terrain. Two controllers govern the integration of online inertial measurement unit and light detection and ranging sensor signals into commands for climbing by means of an abstracted (unicycle) representation of the platform in support of different performance goals: a kinematic version for endurance and a dynamic version for speed. These control laws, backed by a suite of formal correctness guarantees, encourage a stripped‐down sensory suite supporting a simplified world model whose departures from the actual physical environment are handled by the mechanical competence of the legged platform. Both behaviors are implemented on a version of the legged RHex platform, and experiments spanning almost a kilometer (thousands of body lengths) in various challenging settings are conducted.
Effect of depth on food‐web interactions in a thermally stratified floodplain lake following inundation
Authors: Palijan G. , Galir Balkić A.
Published: March 2018

We investigated the controlling mechanisms of microbial and metazooplankton food‐web components at the surface‐ and bottom‐water layers of a thermally stratified floodplain lake (Lake Sakadaš, Kopački Rit floodplain, Croatia) during its connection with the river. Throughout the study, the lake was stratified continuously. The permutational multivariate analysis of variance provided evidence that only the surface‐water layer was impacted on by the flow and flood pulses, whereas the bottom‐water layer represented a zone of stable environmental conditions. The water depth was by one order of magnitude more important in determining environmental variables and plankton abundance than the hydrological phases. Under such circumstances, path analysis provided evidence that the planktonic food‐web interactions were strongly influenced by the sample layer, regardless of the flooding conditions. The transfer of organic matter to higher trophic levels at the surface was dominated by herbivory and, to a lesser extent, by predation, whereas bottom‐water layer was represented by additional routes (bacterivory and omnivory). The transfer of organic matter was different through the investigated water layers, of which the surface‐water layer was additionally structured by the floodplain hydrology.
Quality-Quantity Control Culture Enhances Vasculogenesis and Wound Healing Efficacy of Human Diabetic Peripheral Blood CD34+ Cells
Authors: Tanaka Rica , Masuda Haruchika , Fujimura Satoshi , Ito-Hirano Rie , Arita Kayo , Kakinuma Yusuke , Hagiwara Hiroko , Kado Makiko , Hayashi Ayato , Mita Tomoya , Ogawa Takasuke , Watada Hirotaka , Mizuno Hiroshi , Sawada Naoki , Asahara Takayuki
Published: March 2018

Autologous endothelial progenitor cell (EPC) therapy is commonly used to stimulate angiogenesis in ischemic repair and wound healing. However, low total numbers and functional deficits of EPCs make autologous EPC therapy ineffective in diabetes. Currently, no known ex vivo culture techniques can expand and/or ameliorate the functional deficits of EPCs for clinical usage. Recently, we showed that a quality-quantity culture (QQc) system restores the vasculogenic and wound-healing efficacy of murine diabetic EPCs. To validate these results and elucidate the mechanism in a translational study, we evaluated the efficacy of this QQc system to restore the vasculogenic potential of diabetic human peripheral blood (PB) CD34+ cells. CD34+ cells purified from PB of diabetic and healthy patients were subjected to QQc. Gene expression, vascular regeneration, and expression of cytokines and paracrine mediators were analyzed. Pre- or post-QQc diabetic human PB-CD34+ cells were transplanted into wounded BALB/c nude mice and streptozotocin-induced diabetic mice to assess functional efficacy. Post-QQc diabetic human PB-CD34+ cell therapy significantly accelerated wound closure, re-epithelialization, and angiogenesis. The higher therapeutic efficacy of post-QQc diabetic human PB-CD34+ cells was attributed to increased differentiation ability of diabetic CD34+ cells, direct vasculogenesis, and enhanced expression of angiogenic factors and wound-healing genes. Thus, QQc can significantly enhance the therapeutic efficacy of human PB-CD34+ cells in diabetic wounds, overcoming the inherent limitation of autologous cell therapy in diabetic patients, and could be useful for treatment of not only wounds but also other ischemic diseases.
Concise Review: Altered Versus Unaltered Amniotic Membrane as a Substrate for Limbal Epithelial Cells
Authors: Utheim Tor Paaske , Aass Utheim Øygunn , Salvanos Panagiotis , Jackson Catherine J. , Schrader Stefan , Geerling Gerd , Sehic Amer
Published: March 2018

Limbal stem cell deficiency (LSCD) can result from a variety of corneal disorders, including chemical and thermal burns, infections, and autoimmune diseases. The symptoms of LSCD may include irritation, epiphora, blepharospasms, photophobia, pain, and decreased vision. There are a number of treatment options, ranging from nonsurgical treatments for mild LSCD to various forms of surgery that involve different cell types cultured on various substrates. Ex vivo expansion of limbal epithelial cells (LEC) involves the culture of LEC harvested either from the patient, a living relative, or a cadaver on a substrate in the laboratory. Following the transfer of the cultured cell sheet onto the cornea of patients suffering from LSCD, a successful outcome can be expected in approximately three out of four patients. The phenotype of the cultured cells has proven to be a key predictor of success. The choice of culture substrate is known to affect the phenotype. Several studies have shown that amniotic membrane (AM) can be used as a substrate for expansion of LEC for subsequent transplantation in the treatment of LSCD. There is currently a debate over whether AM should be denuded (i.e., de-epithelialized) prior to LEC culture, or whether this substrate should remain intact. In addition, crosslinking of the AM has been used to increase the thermal and mechanical stability, optical transparency, and resistance to collagenase digestion of AM. In the present review, we discuss the rationale for using altered versus unaltered AM as a culture substrate for LEC.
AES and XPS depth‐profiling of annealed AlN/Ti‐Al/AlN films for high‐temperature applications in SAW metallization
Authors: Oswald S. , Lattner E. , Seifert M. , Menzel S.
Published: March 2018

For the application of surface acoustic wave sensors at high temperatures, both a high‐temperature stable piezoelectric substrate as well as a suitable metallization are needed. Besides the intensively studied Ru‐Al thin films on different substrates with various diffusion barriers and different Ru/Al stoichiometry, also TiAl thin films were investigated because of their high temperature stability. In this study, Ti/Al multilayers have been prepared in combination with AlN cover and buffer layers as oxidation barriers. To form the high‐temperature stable TiAl phase, thermal treatment was done in vacuum at several temperatures. While phase formation was followed by X‐ray diffraction, we used Auger electron spectroscopy and X‐ray photoelectron spectroscopy sputter depth‐profiling to investigate film composition and oxidation behavior. However, the analysis was challenging due to peak overlaps and strong charging effects. In this paper, we discuss the approaches to solve these challenges for quantification of the depth profile results and show how besides some limitations both elemental and chemical information can be collected.
XPSSurfA: An open collaborative XPS data repository using the CMSShub platform
Authors: Barlow Anders J. , Jones Robert T. , McDonald Andrew J. , Pigram Paul J.
Published: March 2018

X‐ray photoelectron spectroscopy (XPS) is a widely used surface analysis technique employed in fundamental research, applied research, service laboratories, and industry. Good‐quality analytical outcomes depend critically on spectral references. Many examples of XPS reference databases exist, including print editions, sets of spectral peak positions drawn from the literature, and digital archives and libraries. We report the development of a new digital XPS database comprising survey spectra and region spectra for a range of materials types, collected under a common set of analytical conditions. Each material is described using spectra collected at multiple pass energies with all photoelectron and X‐ray induced Auger transitions represented. Detailed metadata are provided for each material and each spectrum, presented using a schema that incorporates the ISO 16243 and 14976 standards and extensions developed in this work. Spectra are shared under a Creative Commons International (4.0) attribution, non‐commercial licence (CC BY‐NC) in Kratos (.dset), VAMAS (.vms), and XML (.xml) formats. It is intended that reference spectra be imported directly into XPS data analysis software packages for reference and comparison purposes, matching either the peak or transition of interest and the instrument pass energy. The database is flexible and scalable in structure and has the potential to become a core XPS reference resource.
Surface phenomena during the early stage of liquid phase SPS of a mixture of coarse WC and Ni‐alloy particles
Authors: Maizza G. , Montanari R. , Richetta M. , Varone A. , Kaciulis S. , Mezzi A. , Soltani P.
Published: March 2018

The tool industry strongly demands more economical, high‐performance, healthy, and ecological Co‐free WC‐based composites. Nickel is considered the optimal substitute of Co in WC‐based cermets to attain nearly comparable, if not superior properties in terms of wear resistance and fracture toughness. The combination of WC‐Ni with spark plasma sintering (SPS) process may represent a key factor to enhance the properties of future WC‐Ni composites. This work aims at studying the early stage of liquid phase sintering of a WC‐Ni‐alloy powder mixture made of coarse spheroidal WC (80 vol%) and Ni‐brazing alloy (20 vol%) particles during low pressure (16 MPa) pulsed SPS. Liquid phase phenomena were investigated both morphologically and analytically by energy dispersive X‐ray spectroscopy and X‐ray photoelectron spectroscopy. The results reveal that the interface reaction between the liquid Ni and WC particles causes the formation of an outer reaction shell within the WC particles, which is an Ni‐W solid solution. Most of necks originated between WC particles were favored by the presence of such reaction shell without any liquid interlayer. A relevant presence of graphitic carbon was observed over the surface of WC particles. The larger atomic W2C/WC ratio in the initial WC powder decreased in the compact after SPS owing to the stabilization reaction between W2C and carbon diffusing across the reaction shell.
Surface analysis: From single crystals to biomaterials
Authors: Castner David G.
Published: March 2018

Surfaces and interfaces play a critical role in material performance in many applications including catalysis, biomaterials, microelectronics, tribology, and adhesion. Characterizing the important surfaces and interfaces involved in each application may present different challenges, but the approach to investigating them often is rather similar. Specialized instrumentation is typically used to probe the surface region of a material, and often times it is required to develop new instrumentation and data analysis methods to obtain the desired information. It usually best to use multiple experimental techniques, often coupled with theoretical calculations and simulations, to gain a more complete understanding of the surface and interface regions. Careful handling and preparation of the samples is required so the surface is not altered during these processes as well as during analysis. Using model samples with well‐defined surface structures and compositions can provide information about fundamental processes as well as help develop the analytical tools and methodology needed to characterize complex surfaces and interfaces. Thus, the expertise and experience a surface analyst acquires in one field can be readily applied to other fields, even when those fields are significantly differently (eg, biomaterials and microelectronics). This has resulted in surface analysts moving rather easily between different research and application areas. As one example, my career path of small molecule chemisorption and reactivity on single crystals to industrial catalysis to biomedical surface science is presented in this manuscript.
Oxidative treatment effect on TiH2 powders
Authors: Kaciulis S. , Soltani P. , Mezzi A. , Montanari R. , Lapi G. , Richetta M. , Varone A. , Barbieri G.
Published: March 2018

Titanium hydride (TiH2) is a brittle powder, which is highly reactive when exposed to heat or strong oxidizers. Namely due to its high reactivity, TiH2 powder is widely applied in pyrotechnics, initiator squibs, and igniters. All the industrial applications of TiH2 are based on its decomposition and consequent hydrogen release.

The surface of TiH2 powders has been analysed after different heat treatments in air realized by changing time and temperature. Hydrogen release during heating was investigated by temperature programmed desorption, whereas the crystalline phases were examined by X‐ray diffraction. X‐ray photoelectron spectroscopy (XPS) was used to characterize the chemical states of the surface layers of the treated TiH2 particles. The oxide thickness after different heat treatments was determined by using the XPS depth profiling.

The XPS results revealed the presence of Ti3+ and Ti4+ species on the TiH2 surface. The thickness of titanium oxide layer on the TiH2 particles was estimated from the XPS depth profiles. In general, this work explains the result of an experimental campaign directed to study the effect of various heat treatments on phase transformation and surface structure of TiH2 in relation to hydrogen desorption.
A general approach to evaluating the bias of 2‐stage instrumental variable estimators
Authors: Wan Fei , Small Dylan , Mitra Nandita
Published: March 2018

Unmeasured confounding is a common concern when researchers attempt to estimate a treatment effect using observational data or randomized studies with nonperfect compliance. To address this concern, instrumental variable methods, such as 2‐stage predictor substitution (2SPS) and 2‐stage residual inclusion (2SRI), have been widely adopted. In many clinical studies of binary and survival outcomes, 2SRI has been accepted as the method of choice over 2SPS, but a compelling theoretical rationale has not been postulated. We evaluate the bias and consistency in estimating the conditional treatment effect for both 2SPS and 2SRI when the outcome is binary, count, or time to event. We demonstrate analytically that the bias in 2SPS and 2SRI estimators can be reframed to mirror the problem of omitted variables in nonlinear models and that there is a direct relationship with the collapsibility of effect measures. In contrast to conclusions made by previous studies (Terza et al, 2008), we demonstrate that the consistency of 2SRI estimators only holds under the following conditions: (1) when the null hypothesis is true; (2) when the outcome model is collapsible; or (3) when estimating the nonnull causal effect from Cox or logistic regression models, the strong and unrealistic assumption that the effect of the unmeasured covariates on the treatment is proportional to their effect on the outcome needs to hold. We propose a novel dissimilarity metric to provide an intuitive explanation of the bias of 2SRI estimators in noncollapsible models and demonstrate that with increasing dissimilarity between the effects of the unmeasured covariates on the treatment versus outcome, the bias of 2SRI increases in magnitude.
Grouping methods for estimating the prevalences of rare traits from complex survey data that preserve confidentiality of respondents
Authors: Hyun Noorie , Gastwirth Joseph L. , Graubard Barry I.
Published: March 2018

Originally, 2‐stage group testing was developed for efficiently screening individuals for a disease. In response to the HIV/AIDS epidemic, 1‐stage group testing was adopted for estimating prevalences of a single or multiple traits from testing groups of size q, so individuals were not tested. This paper extends the methodology of 1‐stage group testing to surveys with sample weighted complex multistage‐cluster designs. Sample weighted‐generalized estimating equations are used to estimate the prevalences of categorical traits while accounting for the error rates inherent in the tests. Two difficulties arise when using group testing in complex samples: (1) How does one weight the results of the test on each group as the sample weights will differ among observations in the same group. Furthermore, if the sample weights are related to positivity of the diagnostic test, then group‐level weighting is needed to reduce bias in the prevalence estimation; (2) How does one form groups that will allow accurate estimation of the standard errors of prevalence estimates under multistage‐cluster sampling allowing for intracluster correlation of the test results. We study 5 different grouping methods to address the weighting and cluster sampling aspects of complex designed samples. Finite sample properties of the estimators of prevalences, variances, and confidence interval coverage for these grouping methods are studied using simulations. National Health and Nutrition Examination Survey data are used to illustrate the methods.
Osmotic Effects in Track‐Etched Nanopores
Authors: Apel Pavel Y. , Blonskaya Irina V. , Lizunov Nikolay E. , Olejniczak Katarzyna , Orelovitch Oleg L. , Toimil‐Molares María E. , Trautmann Christina
Published: March 2018

Asymmetrically etched ion‐track membranes attract great interest for both fundamental and technical reasons because of a large variety of applications. So far, conductometric measurements during track etching provide only limited information about the complicated asymmetric etching process. In this paper, monitoring of osmotic phenomena is used to elucidate the initial phase of nanopore formation. It is shown that strong alkaline solutions generate a considerable osmotic flow of water through newborn conical pores. The interplay between diffusion and convection in the pore channel results in a substantially nonlinear alkali concentration gradient and a rapid change in the pore geometry after breakthrough. Similar phenomena are observed in experiments with cylindrical track‐etched pores of 15–30 nm in radius. A theoretical description of the diffusion–convection processes in the pores is provided.
Nanostructure and Microstructure Fabrication: From Desired Properties to Suitable Processes
Authors: van Assenbergh Peter , Meinders Erwin , Geraedts Jo , Dodou Dimitra
Published: March 2018

When designing a new nanostructure or microstructure, one can follow a processing‐based manufacturing pathway, in which the structure properties are defined based on the processing capabilities of the fabrication method at hand. Alternatively, a performance‐based pathway can be followed, where the envisioned performance is first defined, and then suitable fabrication methods are sought. To support the latter pathway, fabrication methods are here reviewed based on the geometric and material complexity, resolution, total size, geometric and material diversity, and throughput they can achieve, independently from processing capabilities. Ten groups of fabrication methods are identified and compared in terms of these seven moderators. The highest resolution is obtained with electron beam lithography, with feature sizes below 5 nm. The highest geometric complexity is attained with vat photopolymerization. For high throughput, parallel methods, such as photolithography (≈101m2h−1), are needed. This review offers a decision‐making tool for identifying which method to use for fabricating a structure with predefined properties.
The State and Challenges of Anode Materials Based on Conversion Reactions for Sodium Storage
Authors: Wu Chao , Dou Shi‐Xue , Yu Yan
Published: March 2018

Sodium‐ion batteries (SIBs) have huge potential for applications in large‐scale energy storage systems due to their low cost and abundant sources. It is essential to develop new electrode materials for SIBs with high performance in terms of energy density, cycle life, and cost. Metal binary compounds that operate through conversion reactions hold promise as advanced anode materials for sodium storage. This Review highlights the storage mechanisms and advantages of conversion‐type anode materials and summarizes their recent development. Although conversion‐type anode materials have high theoretical capacities and abundant varieties, they suffer from multiple challenging obstacles to realize commercial applications, such as low reversible capacity, large voltage hysteresis, low initial coulombic efficiency, large volume changes, and low cycling stability. These key challenges are analyzed in this Review, together with emerging strategies to overcome them, including nanostructure and surface engineering, electrolyte optimization, and battery configuration designs. This Review provides pertinent insights into the prospects and challenges for conversion‐type anode materials, and will inspire their further study.
Nanostructuring Lipophilic Dyes in Water Using Stable Vesicles, Quatsomes, as Scaffolds and Their Use as Probes for Bioimaging
Authors: Ardizzone Antonio , Kurhuzenkau Siarhei , Illa‐Tuset Sílvia , Faraudo Jordi , Bondar Mykhailo , Hagan David , Van Stryland Eric W. , Painelli Anna , Sissa Cristina , Feiner Natalia , Albertazzi Lorenzo , Veciana Jaume , Ventosa Nora
Published: March 2018

A new kind of fluorescent organic nanoparticles (FONs) is obtained using quatsomes (QSs), a family of nanovesicles proposed as scaffolds for the nanostructuration of commercial lipophilic carbocyanines (1,1′‐dioctadecyl‐3,3,3′,3′‐tetramethyl‐indocarbocyanine perchlorate (DiI), 1,1′‐dioctadecyl‐3,3,3′,3′‐tetramethyl‐indodicarbocyanine perchlorate (DiD), and 1,1′‐dioctadecyl‐3,3,3′,3′‐tetramethyl‐indotricarbocyanine iodide (DiR)) in aqueous media. The obtained FONs, prepared by a CO2‐based technology, show excellent colloidal‐ and photostability, outperforming other nanoformulations of the dyes, and improve the optical properties of the fluorophores in water. Molecular dynamics simulations provide an atomistic picture of the disposition of the dyes within the membrane. The potential of QSs for biological imaging is demonstrated by performing superresolution microscopy of the DiI‐loaded vesicles in vitro and in cells. Therefore, fluorescent QSs constitute an appealing nanomaterial for bioimaging applications.
Probing Adsorption Behaviors of BSA onto Chiral Surfaces of Nanoparticles
Authors: Wang Xinyi , Wang Xiaofeng , Wang Mingzhe , Zhang Di , Yang Qi , Liu Tao , Lei Rong , Zhu Shuifang , Zhao Yuliang , Chen Chunying
Published: March 2018

Chiral properties of nanoscale materials are of importance as they dominate interactions with proteins in physiological environments; however, they have rarely been investigated. In this study, a systematic investigation is conducted for the adsorption behaviors of bovine serum albumin (BSA) onto the chiral surfaces of gold nanoparticles (AuNPs), involving multiple techniques and molecular dynamic (MD) simulation. The adsorption of BSA onto both L‐ and D‐chiral surfaces of AuNPs shows discernible differences involving thermodynamics, adsorption orientation, exposed charges, and affinity. As a powerful supplement, MD simulation provides a molecular‐level understanding of protein adsorption onto nanochiral surfaces. Salt bridge interaction is proposed as a major driving force at protein–nanochiral interface interaction. The spatial distribution features of functional groups (COO−, NH3+, and CH3) of chiral molecules on the nanosurface play a key role in the formation and location of salt bridges, which determine the BSA adsorption orientation and binding strength to chiral surfaces. Sequentially, BSA corona coated on nanochiral surfaces affects their uptake by cells. The results enhance the understanding of protein corona, which are important for biological effects of nanochirality in living organisms.
Directed Self‐Assembly of Star‐Block Copolymers by Topographic Nanopatterns through Nucleation and Growth Mechanism
Authors: Krishnan Mohan Raj , Lu Kai‐Yuan , Chiu Wen‐Yu , Chen I‐Chen , Lin Jheng‐Wei , Lo Ting‐Ya , Georgopanos Prokopios , Avgeropoulos Apostolos , Lee Ming‐Chang , Ho Rong‐Ming
Published: March 2018

Exploring the ordering mechanism and dynamics of self‐assembled block copolymer (BCP) thin films under confined conditions are highly essential in the application of BCP lithography. In this study, it is aimed to examine the self‐assembling mechanism and kinetics of silicon‐containing 3‐arm star‐block copolymer composed of polystyrene (PS) and poly(dimethylsiloxane) blocks as nanostructured thin films with perpendicular cylinders and controlled lateral ordering by directed self‐assembly using topographically patterned substrates. The ordering process of the star‐block copolymer within fabricated topographic patterns with PS‐functionalized sidewall can be carried out through the type of secondary (i.e., heterogeneous) nucleation for microphase separation initiated from the edge and/or corner of the topographic patterns, and directed to grow as well‐ordered hexagonally packed perpendicular cylinders. The growth rate for the confined microphase separation is highly dependent upon the dimension and also the geometric texture of the preformed pattern. Fast self‐assembly for ordering of BCP thin film can be achieved by lowering the confinement dimension and also increasing the concern number of the preformed pattern, providing a new strategy for the design of BCP lithography from the integration of top‐down and bottom‐up approaches.
Nanodiamonds and Their Applications in Cells
Authors: Chipaux Mayeul , van der Laan Kiran J. , Hemelaar Simon R. , Hasani Masoumeh , Zheng Tingting , Schirhagl Romana
Published: March 2018

Diamonds owe their fame to a unique set of outstanding properties. They combine a high refractive index, hardness, great stability and inertness, and low electrical but high thermal conductivity. Diamond defects have recently attracted a lot of attention. Given this unique list of properties, it is not surprising that diamond nanoparticles are utilized for numerous applications. Due to their hardness, they are routinely used as abrasives. Their small and uniform size qualifies them as attractive carriers for drug delivery. The stable fluorescence of diamond defects allows their use as stable single photon sources or biolabels. The magnetic properties of the defects make them stable spin qubits in quantum information. This property also allows their use as a sensor for temperature, magnetic fields, electric fields, or strain. This Review focuses on applications in cells. Different diamond materials and the special requirements for the respective applications are discussed. Methods to chemically modify the surface of diamonds and the different hurdles one has to overcome when working with cells, such as entering the cells and biocompatibility, are described. Finally, the recent developments and applications in labeling, sensing, drug delivery, theranostics, antibiotics, and tissue engineering are critically discussed.
A Modular System for the Design of Stimuli‐Responsive Multifunctional Nanoparticle Aggregates by Use of Host–Guest Chemistry
Authors: Engel Sabrina , Möller Nadja , Stricker Lucas , Peterlechner Martin , Ravoo Bart Jan
Published: March 2018

A self‐assembly approach for the design of multifunctional nanomaterials consisting of different nanoparticles (gold, iron oxide, and lanthanide‐doped LiYF4) is developed. This modular system takes advantage of the light‐responsive supramolecular host–guest chemistry of β‐cyclodextrin and arylazopyrazole, which enables the dynamic and reversible self‐assembly of particles to spherical nanoparticle aggregates in aqueous solution. Due to the magnetic iron oxide nanoparticles, the aggregates can be manipulated by an external magnetic field leading to the formation of linear structures. As a result of the integration of upconversion nanoparticles, the aggregates are additionally responsive to near‐infrared light and can be redispersed by use of the upconversion effect. By varying the nanoparticle and linker concentrations the composition, size, shape, and properties of the multifunctional nanoparticle aggregates can be fine‐tuned.
Supramolecular Vesicles for Stimulus‐Responsive Drug Delivery
Authors: Xing Pengyao , Zhao Yanli
Published: March 2018

Developing smart controlled‐release systems for cancer therapy is highly desired in biomedicine. In order to improve therapeutic efficacy and lower undesired side effects, the construction of stimulus‐responsive nanocarriers is a favorable solution. Emerging supramolecular self‐assemblies possessing intrinsic dynamic and adaptive features present promising capabilities for the fabrication of stimulus‐responsive drug‐release systems. Dynamic supramolecular vesicles have attracted considerable attention as therapeutic carriers ascribed to their advantages of high‐cargo‐loading capacity/feasibility, excellent biocompatibility, and facile functionalization. Here, a summary and discussion of recent significant development of vesicles constructed by supramolecular self‐assembly for stimulus‐responsive drug delivery and therapeutics is given. Through presenting some representative studies, strategies regarding the design, synthesis, characterization, and biomedical applications of supramolecular vesicle carriers are highlighted according to various stimulus triggers. The aim is to provide a quick research update in this rapidly developing field.
A Hierarchical MoP Nanoflake Array Supported on Ni Foam: A Bifunctional Electrocatalyst for Overall Water Splitting
Authors: Jiang Yuanyuan , Lu Yizhong , Lin Jianyi , Wang Xin , Shen Zexiang
Published: March 2018

The search for an inexpensive bifunctional electrocatalyst for overall water splitting has attracted considerable research interest during the past years. Herein, self‐supported hierarchical electrodes comprising nickel foam (NF) and porous molybdenum phosphide (MoP) nanoflakes are fabricated by first growing MoO2 nanoflakes on Ni foam and then further phosphorization treatment. Remarkably, serving as both anode and cathode catalysts in a two‐electrode alkaline water‐electrolysis system, the designed electrodes only require a potential of 1.62 V to deliver a current density of 10 mA cm−2. This performance is close to that of the noble‐metal‐based electrodes, that is, integrated RuO2/Ni foam and Ni foam supported Pt/C electrodes. The low cost, facile preparation method, and desirable performance make this MoP/NF electrode a potential electrocatalyst for overall water splitting.