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A scaffold was fabricated to synergistically encapsulate living human adipose-derived stem cells (hASCs) and platelet-rich plasma (PRP) based on a vapor-phase sublimation and deposition process. During the process, ice templates were prepared using sterile water as the solvent and were used to accommodate the sensitive living cells and PRP molecules. Under controlled processing conditions, the ice templates underwent vapor sublimation to evaporate water molecules, while at the same time, vapor-phase deposition of poly

An elegant and precise method to fabricate asymmetrical structures and/or gradient structures was developed based on a vapor-phase sublimation and deposition process. The fabricated materials exhib...

Bottom–up approaches using building blocks of modules to fabricate scaffolds for tissue engineering applications have enabled the fabrication of structurally complex and multifunctional materials allowing for physical and chemical flexibility to better mimic the native extracellular matrix. Here we report a vapor-phased fabrication process for constructing three-dimensional modulated scaffold materials via simple steps based on controlling mass transport of vapor sublimation and deposition. We demonstrate the fabrication of scaffolds comprised of multiple biomolecules and living cells with built-in boundaries separating the distinct compartments containing defined biological configurations and functions. We show that the fabricated scaffolds have mass production potential. We demonstrate overall >80% cell viability of encapsulated cells and that modulated scaffolds exhibit enhanced cell proliferation, osteogenesis, and neurogenesis, which can be assembled into various geometric configurations. We perform cell co-culture experiments to show independent osteogenesis and angiogenesis activities from separate compartments in one scaffold construct., Current methods for the modular assembly of biomaterials are associated with limitations. Here the authors implement vapor-phase deposition to fabricate 3D polymeric materials that permit biomolecule functionalization, tunable mass transport and mechanical properties, as well as control over boundaries between compartments, and analyze the behavior of 3D encapsulated cells.

Modifications of biomaterials based on the combination of physical, chemical, and biological cues for manipulating stem cell growth are needed for modern regenerative medicine. The exploitation of these sophisticated modifications remains a challenge, including substrate limitation, biocompatibility, and versatile and general cues for stem cell activities. In this report, a vapor-phase coating technique based on the functionalization of poly-p-xylylene (PPX) was used to generate a surface modification for use with stem cells in culture. The coating provided the ability for covalent conjugation that immobilized bone morphogenetic protein 2 (BMP-2) and fibroblast growth factor 2 (FGF-2), and the modified coating surfaces enabled direct stem cell differentiation and controlled proliferation because of the specific activities. The ligations were realized between the growth factors and the maleimide-modified surface, and the conjugation reactions proceeded with high specificity and rapid kinetics under mild conditions. The conjugation densities were approximately 140 ng·cm−2 for BMP-2 and 155 ng·cm−2 for FGF-2. Guiding the activities of the human adipose-derived stem cells (hADSCs) was achieved by modifying surfaces to promote the hADSC differentiation capacity and proliferation rate. The reported coating system demonstrated biocompatibility, substrate-independent conformity, and stability, and it could provide an effective and versatile interface platform for further use in biomedical applications.

Surface modification layers are performed on the surfaces of biomaterials and have exhibited promise for decoupling original surface properties from bulk materials and enabling customized and advanced functional properties. The physical stability and the biological compatibility of these modified layers are equally important to ensure minimized delamination, debris, leaching of molecules, and other problems that are related to the failure of the modification layers and thus can provide a long-term success for the uses of these modified layers. A proven surface modification tool of the functionalized poly-para-xylylene (PPX) system was used as an example, and in addition to the demonstration of their chemical conjugation capabilities and the functional properties that have been well-documented, in the present report, we additionally devised the characterization protocols to examine stability properties, including thermostability and adhesive strength, as well as the biocompatibility, including cell viability and the immunological responses, for the modified PPX layers. The results suggested a durable coating stability for PPXs and firmly attached biomolecules under these stability and compatibility tests. The durable and stable modification layers accompanied by the native properties of the PPXs showed high cell viability against fibroblast cells and macrophages (MΦs), and the resulting immunological activities created by the MΦs exhibited excellent compatibility with non-activated immunological responses and no indication of inflammation.

A prospective design for interface properties is enabled to perform precise functionalization, erasure capability for existing properties, reactivation of surface functionality to a second divergent property. A vapor-deposited, 2-nitro-5-(prop-2-yn-1-yloxy)methylbenzyl carbamate-functionalized poly-para-xylylene coating is synthesized in this study to realize such tasks by offering the accessibility of the azide/alkyne click reaction, an integrated photochemical decomposition/cleavage moiety, and the reactivation sites of amines behind the cleavage that allow the installation of a second surface function. With the benefits from the mild processing conditions used for the coatings and the rapid response of the photochemical reaction, the creation of sophisticated interface properties and localized chemical compositions was elegantly demonstrated with a hybrid functionality including a confined hydrophlic/hydrophobic wetting property and/or a cell adherent/repellent platform on such a coating surface.

The field of implantable electronics relies on using silicon materials due to the merits of a well-established fabrication process and favorable properties; of particular interest is the surface modification of such materials. In the present study, we introduce a surface modification technique based on coatings of functionalized Parylene on silicon substrates, where the modified layers provide a defined cell adhesion capability for the resultant silicon materials/devices. Functionalization of Parylene was achieved during a one-step chemical vapor deposition (CVD) polymerization process, forming NHS ester-functionalized Parylene, and subsequent RGD attachment was enabled via a conjugation reaction between the NHS ester and amine groups. The modification procedures additionally provided a clean and gentle approach to avoid thermal excursions, intense irradiation, chemicals, or solvents that might damage delicate structures or sensitive molecules on the devices. The modification layers exhibited excellent mechanical strength on the substrate, meeting the high standards of the American Society for Testing and Materials (ASTM), and the resultant cell adherence property was verified by a centrifugation assay and the analysis of attached cell morphologies; the results collectively demonstrated robust and sustainable modification layers of the NHS ester-functionalized Parylene and confirmed that the cell-adherence property imparted by using this facile modification technique was effective. The modification technology is expected to benefit the design of prospective interface properties for silicon-based devices and related industrial products.

An advanced material interface is modified by using a substrate-independent coating of detachable poly-para-xylylene, enabling dynamical control of the immobilization and detachment of biomolecules, and a previously installed biological function is deactivated or tuned with reduced activity. The induction of osteogenesis activity, and subsequent deactivation of such osteogenesis activity, is demonstrated.

Surface modification layers are needed for the precise definition of surface chemistries and are equally important for durable and stable adhesive properties to ensure long-term stability and effective performance for biotechnological applications. This study demonstrates a robust modification layer that is synthesized based on chemical vapor deposition copolymerization, and the resultant coating layer is composed of the side-by-side presentation of N-hydroxysuccinimide ester and maleimide functionalities with a controlled ratio to define the immobilization accessibility of chitosan and growth factor protein (FGF-2) molecules on the substrate surface for enhancing cellular activities of stem cells. Characterizations of the copolymer modification layer showed excellent durability, including adhesive strength and thermal stability, and the layer is free of concerns for delamination and/or unacceptable deformation/debris formation that can cause potential toxicity to the surrounding biological environment. Modifications using the copolymer layer on the cell culture surface have demonstrated synergistic activity by chitosan to support the formation of spheroids and by FGF-2 to enhance the proliferation of human adipose-derived stem cells (ADSCs) within the spheroids while increasing the spheroid size and cell numbers. Healthy and flourishing growth activities were discovered for ADSCs on the modified culture surfaces, and the results are useful for potential and related stem cell research and the interfaces of biomaterials.

Multifunctional nanoparticles featuring three distinct and orthogonal functionalities for performing catalyst-free click reactions of azide-alkyne and maleimide-thiol and atom transfer radical polymerization (ATRP) are fabricated using a simple chemical vapor deposition copolymerization approach with the flexibility to control the particle size and geometry.

The interfacial reactions between the Ni barrier layer and the popularly used P-type (Bi0.25Sb0.75)2Te3 and N-type Bi2(Te0.9Se0.1)3 thermoelectric substrates are examined at 300 °C and 250 °C. A NiTe2 phase with significant Sb solubility, or a ternary compound, and a Bi-enriched (Bi, Sb)2Te3 phase are formed in the Ni/(Bi0.25Sb0.75)2Te3 couples. Two phases, NiTe2 and BiTe, are formed in the Ni/Bi2(Te0.9Se0.1)3 couples. Both of these two phases have significant ternary solubilities. The Bi Ni Sb Te and Bi Ni Se Te phase diagrams at 300 °C are proposed based on very limited available phase diagrams of constituent binary and ternary systems. Their respective reaction paths in both couples are drawn on isothermal tetrahedrons. The average reaction rates in 10 days are 7 μm/day at 300 °C and 0.9 μm/day at 250 °C in the Ni/Bi2(Te0.9Se0.1)3 couples, and they are much faster compared to those in the Ni/(Bi0.25Sb0.75)2Te3 couples, which are 0.9 μm/day at 300 °C and 0.4 μm/h at 250 °C. It is concluded Te is the fastest diffusion species in both types of couples.

We report the synthesis of functionalised quinolin-2-(1H)-one analogues by a one-pot approach through a tandem consecutive Ugi-4CR/intramolecular alkyne-carbonyl metathesis (ACM) type reaction, in which Pd(OAc)2 is used as a catalyst in the presence of acetic acid. The first step is the preparation of an Ugi-4CR intermediate using simple precursors 2′-aminoacetophenone and cyclohexyl isocyanide with various propiolic acids and aldehydes.

In this study, poly-para-xylylene-based multifunctional nanoparticles (PPX-NPs) were fabricated. Based on the solubility characteristics determined for asymmetrically substituted poly-para-xylylenes in polar solvents, well-dispersed nanocolloids with a controllable size ranging from 50 to 800nm were produced in solution by the displacement of the solvent (water). These size ranges were found to have acceptable cellular compatibility through examinations of cultured 3T3 fibroblasts and adipose-derived stem cells treated with the PPX-NPs. In addition, these nanoscale PPX-NPs exhibited versatile bioconjugation properties in that a variety of available functional groups can be adopted from their counterpart, thin-film poly-para-xylylenes, during the production of these nanoparticles. For instance, bifunctional PPX-NPs with maleimide and benzoyl moieties were produced to enable immobilization via a maleimide-thiol reaction concurrent with a photochemical reaction. A cleavable PPX-NP was also produced with a thiol-exchangeable surface property. Additionally, by performing electrohydrodynamic jetting of parallel polymer solutions of selected poly-para-xylylenes, Janus-type or multicompartment PPX-NPs were created. The PPX-NPs can potentially be used for various biomedical applications such as combined diagnostics and drug delivery, multiplexing of detection, multiple-drug loading, and the targeted delivery of biomolecules or drugs.

Baculoviral anti-apoptotic genes, p35 and iap (inhibitor of apoptosis), play important roles in the initiation stage of viral infection. While some iap genes in baculoviruses are not directly involved in anti-apoptotic activity, two iap genes (ly-iap2 and ly-iap3) were found and cloned from Lymantria xylina multiple nucleopolyhedrovirus (LyxyMNPV) and used to investigate the roles in LyxyMNPV infection. From the transcriptional start site analysis, ly-iap2 consisted of a late promoter motif (TAAG) located upstream at nt −17 bp, and ly-iap3 had a potential baculoviral promoter consensus sequence (GCTTGTT) located upstream at nt −44 bp. Both the ly-iap2 and ly-iap3 genes were initially transcribed in the LyxyMNPV-infected Ld652Y cells (IPLB-LD652Y cell line) at 3 h post infection (h p.i.), increased dramatically at 12 h p.i. and reached the peak at 72 h p.i. according to a quantitative RT-PCR (qRT-PCR) assay. Functional assays of these iap genes were performed using an overexpression method in Sf9 cells. Full-length LY-IAP2, LY-IAP3 and LY-IAP2-BIR (baculoviral IAP repeat) could inhibit varying degrees of apoptosis induced by Drosophila RPR protein (DRPR). Interestingly, Ly-IAP2-BIR showed higher inhibitory activity than full-length Ly-IAP2, and the protein expression level was dramatically increased while the Ly-IAP2-RING domain was deleted. The effect of MG-132 on the overexpression of Ly-IAP2 was investigated. Under MG-132 treatments, high-molecular-weight signals were also detected. Taken together, this study suggested that both Ly-IAP2 and Ly-IAP3 were anti-apoptotic protein through the BIR functional domain. The Ly-IAP2-RING domain was possibly involved in ubiquitin E3 ligase activity, leading to the degradation of Ly-IAP2 protein, whereas Ly-IAP3-RING might be working as a “helper domain” to inhibit DRPR-induced apoptosis.

"Click" reactions provide precise and reliable chemical transformations for the preparation of functional architectures for biomaterials and biointerfaces. The emergence of a multiple-click reaction strategy has paved the way for a multifunctional microenvironment with orthogonality and precise multitasking that mimics nature. We demonstrate a multifaceted and route-controlled click interface using vapor-deposited functionalized poly-para-xylylenes. Distinctly clickable moieties of ethynyl and maleimide were introduced into poly-para-xylylenes in one step via a chemical vapor deposition (CVD) copolymerization process. The advanced interface coating allows for a double-click route with concurrent copper(i)-catalyzed Huisgen 1,3-dipolar cycloaddition (CuAAC) and the thiol-maleimide click reaction. Additionally, double-click reactions can also be performed in a cascade manner by controlling the initiation route to enable the CuAAC and/or thiol-yne reaction using a mono-functional alkyne-functionalized poly-para-xylylene. The use of multifaceted coatings to create straightforward and orthogonal interface properties with respect to protein adsorption and cell attachment is demonstrated and characterized.

The bottom-up patterning approach provides intrinsic advantages associated with unlimited resolution but is limited by the materials available for selection. A general and simple approach towards the selective deposition of poly-para-xylylenes is introduced in this communication. The chemical vapour deposition (CVD) of poly-para-xylylenes is inhibited on the high-energy surfaces of electrically charged conducting substrates. This technology provides an approach to selectively deposit poly-para-xylylenes irrespective of the substituted functionality and to pattern these polymer thin films from the bottom up.

An innovative intraocular lens (IOL) device was fabricated based on a chemical vapor deposition encapsulation process using functionalized poly-p-xylylenes. The advanced IOL device provides noncompromised design parameters for both its optical and biological properties. As an excellent optical device, it provides a high refractive index and a tunable effective focal length that is realized by manipulating the wetting properties of the encapsulated liquids; the device also offers protection from UV radiation. As a key medical device, it exhibits excellent biocompatibility and reduced postoperative calcification through the intrinsic properties of poly-p-xylylenes. In addition, these synergic functions are provided with precise surface chemistry for location to a guided attachment or repellent properties for eye epithelial cells, which is important in preventing device-associated complications.

An electrically induced bottom-up process was introduced for the fabrication of multifunctional nanostructures of polymers. Without requiring complicated photolithography or printing techniques, the fabrication process first produced a conducting template by colloidal lithography to create an interconnected conduction pathway. By supplying an electrical charge to the conducting network, the conducting areas were enabled with a highly energized surface that generally deactivated the adsorbed reactive species and inhibited the vapor deposition of poly- p-xylylene polymers. However, the template allowed the deposition of ordered poly- p-xylylene nanostructures only on the confined and negative areas of the conducting template, in a relatively large centimeter-scale production. The wide selection of functionality and multifunctional capability of poly- p-xylylenes naturally rendered the synergistic and orthogonal chemical reactivity of the resulting nanostructures. With only a few steps, the construction of a nanometer topology with the functionalization of multiple chemical conducts can be achieved, and the selected deposition process represents a state-of-the-art nanostructure fabrication in a simple and versatile approach from the bottom up.

Bi 2 (Te 1− x Se x ) 3 is an important kind of n-type thermoelectric material. In this study, interfacial reactions at 250 °C in the Sn/Bi 2 Te 3 , Sn/Bi 2 Se 3 and Sn/Bi 2 (Te 1− x Se x ) 3 couples are examined. In the Sn/Bi 2 Te 3 couple, the reaction zone is found to be non-planar and the reaction path is liquid/(liquid + SnTe)/Bi 2 Te 3 . But with only 2.0 at.%Se addition to the Bi 2 Te 3 substrate, very different reaction results are observed. In the Sn/Bi 2 (Te 1− x Se x ) 3 couple, the reaction layers are planar, and the reaction path is liquid/SnTe/BiTe x /Bi 2 (Te 1− x Se x ) 3 . In the Sn/Bi 2 Se 3 couple, the reaction layers are also planar, the reaction path is liquid/SnSe/BiSe/Bi 2 Se 3 , and the Bi content in the SnSe phase varies. The growth rates in the Sn/Bi 2 Te 3 couples are very fast, and the reaction layer is as thick as 1174 μm in just 15 min. Very dramatic reduction of growth rates has been observed with Se addition to the substrates, and the reaction layer is only 9 μm in the Sn/Bi 2 (Te 2.9 Se 0.1 ) couples after reaction for 30 min.

The ability to induce osteointegration was introduced to a parylene-C surface via the simple and intuitive process of protein adsorption mediated by hydrophobic interactions. In this way, bone morphogenetic protein (BMP)-2, fibronectin, and platelet-rich plasma (PRP) could be immobilized on parylene-C surfaces. This approach alleviates concerns related to the use of potentially harmful substances in parylene-C modification processes. The adsorbed protein molecules were quantitatively characterized with respect to adsorption efficacy and binding affinity, and the important biological activities of the proteins were also examined using both early and late markers of osteogenetic activity, including alkaline phosphatase expression, calcium mineralization and marker gene expression. Additionally, the adsorbed PRP exhibited potential as a substitute for expensive recombinant growth factors by effectively inducing comparable osteogenetic activity. In addition to the excellent biocompatibility of parylene-C and its ability to coat a wide variety of substrate materials, the modification of parylene-C via protein adsorption provides unlimited possibilities for installing specific biological functions, expanding the potential applications of this material to include various biointerface platforms.

(Bi 1− x Sb x ) 2 Te 3 is important for thermoelectric applications, and Sn is the major element for most electronic solders. This study examines interfacial reactions in the Sn/(Bi 0.25 Sb 0.75 ) 2 Te 3 and Sn/Sb 2 Te 3 couples at 250 °C. It has been observed that the interfacial reaction rates are extremely fast, and the growth rates of the layers are 27 μm/min and 19 μm/min, respectively. The initial reaction product is SnTe phase with nano-size pores which are filled with liquid. With prolonged reaction time, the nano-size liquid droplets connect together and form periodic liquid layer in the reaction zone. The liquid layer, which is primarily molten Sn, further reacts with Sb, and a self-assembled Sn 3 Sb 2 /SnTe alternating layer is found in the couples reacted for longer than 15 min. Bi precipitates with feature size less than one micron are found as well in the reaction zone in the Sn/(Bi 0.25 Sb 0.75 ) 2 Te 3 couples in the later stage of reactions. The alternating layer and Bi precipitates result from supersaturation of Sb and Bi in the reaction layer caused by the fast in-flux of Sn.

In this letter, a novel miniaturized multilayer internally printed antenna combined with two FR4 materials for triple Long Term Evolution (LTE) band operation is proposed. The proposed antenna is designed using a capacitive feed structure and an orthogonal meander line at the top edge of a subsection of the complete structure with dimensions of only 14 × 15 × 3.2 mm3. This covers triple-band operation (LTE700, LTE2300, and LTE2500). The complete dimensions of the mobile device are 50 × 100 mm2. The reflection coefficient is measured and used to demonstrate that the operation bandwidth is 42 MHz in LTE700 operation by a 3:1 VSWR. It is also suited to two full-band operations (LTE2300 and LTE2500) by using the definition of the -10-dB reflection coefficient in two higher modes of operation.

A multicomponent functional polymer is synthesized to support specific reactivity for successful conjugation with the vast array of functionality present in biological systems and the flexibility to conjugate biomolecules without requiring additional modification to install a terminal functional group. The multifunctional surface is realized using a novel coating composed of distinct N-hydroxysuccinimide (NHS) ester and benzoyl functionalities, which can provide accessibility to both the NHS ester-amine coupling reaction and the photochemically induced benzophenone crosslinking reaction, respectively. In addition, the multifunctional polymer is fabricated and transformed to form nanoscale colloids through the solvent displacement of a water/DMF system due to solubility characteristics of the resulting polymer with high polarity. A facile and efficient fabrication approach using the multifunctional nanocolloid is thus demonstrated to create a drug carrier by installing paclitaxel and folic acid for targeted cancer therapy.

Multifunctional biomaterial surfaces can be created by controlling the competing adsorption of multiple proteins. To demonstrate this concept, bone morphogenetic protein 2 (BMP-2) and fibronectin were adsorbed to the hydrophobic surface of polychloro-para-xylylene. The resulting adsorption properties on the surface depended on the dimensional and steric characteristics of the selected protein molecule, the degree of denaturation of the adsorbed proteins, the associated adsorption of interphase water molecules within the protein layers, and the aggregation of proteins in a planar direction with respect to the adsorbent surface. Additionally, a defined surface composition was formed by the competing adsorption of multiple proteins, and this surface composition was directly linked to the composition of the protein mixture in the solution phase. Although the mechanism of this complex competing adsorption process is not fully understood, the adsorbed proteins were irreversibly adsorbed and were unaffected by the further adsorption of homologous or heterologous proteins. Moreover, synergistic biological activities, including cell osteogenesis and proliferation independently and specifically induced by BMP-2 or fibronectin, were observed on the modified surface, and these biological activities were positively correlated with the surface composition of the multiple adsorbed proteins. These results provide insights and important design parameters for prospective biomaterials and biointerfaces for (multi)functional modifications. The ability to control protein/interface properties will be beneficial for the processing of biomaterials for clinical applications and industrial products.

Chemical or biological gradients that are composed of multifunctional and/or multidirectional guidance cues are of fundamental importance for prospective biomaterials and biointerfaces. As a proof of concept, a general modification approach for generating multifunctional and continuous gradients was realized via two controlled and reversed click reactions, namely, thermo-activated thiol-yne and copper-free alkyne and azide click reactions. The cell adhesion property of fibroblasts was guided in a gradient with an enhancement, showing that the PEG molecule and RGD peptide were countercurrently immobilized to form such reversed gradients (with negating of the cell adhesion property). Using the gradient modification protocol to also create countercurrent distributions of FGF-2 and BMP-2 gradients, the demonstration of not only multifunctional but also gradient biointerfacial properties was resolved in time latencies on one surface by showing the manipulation in gradients toward proliferation and osteogenic differentiation for adipose-derived stem cells.

The immobilization of biofunctional molecules to biomaterial surfaces has enabled and expanded the versatility of currently available biomaterials to a wider range of applications. In addition, immobilized biomolecules offer modified surfaces that allow the use of smaller amounts of potentially harmful substances or prevent overdose, while the exhibited biological functions remain persistently effective. Surface concentrations of chlorhexidine (CHX) (1.40 ± 0.08 × 10− 9 mol·cm− 2) and bone morphogenetic protein 2 (BMP-2) (1.51 ± 0.08 × 10− 11 mol·cm− 2) immobilized molecules were determined in this study, and their specific biological functions in terms of antibacterial activity and osteogenesis potency, respectively, were demonstrated to be unambiguously effective. Immobilization exploits the use of vapor-based poly-p-xylylenes, which exhibit excellent biocompatibility and wide applicability for various substrate materials. This technique represents a practical and economical approach for the manufacture of certain industrial products. Furthermore, a minimal degree of macrophage activation was indicated on the modified surfaces via insignificant morphological changes and low levels of adverse inflammatory signals, including suppressed production of the pro-inflammatory cytokines IL-1β and TNF-α as well as nitric oxide (NO). The results and the modification strategy illustrate a concept for designing prospective biomaterial surfaces such that the manipulation employed to elicit targeted biological responses does not compromise immunological compatibility.

Layered hexagonal-boron nitride (h-BN) films were synthesized by chemical vapor deposition (CVD) on Ni foils using ammonia borane as a precursor. Confocal Raman spectroscopy and electron backscatter diffraction (EBSD) were used to probe the effect of underlying Ni crystals with various orientations on growth behaviors of h-BN layers. The growth of the h-BN layers strongly depends on the Ni crystal orientations, where the growth rate of h-BN is larger on Ni(100)-like crystal surfaces but the growth on Ni(111)-like surfaces is not detectable, suggesting that Ni (100)-like facets are likely to promote the growth of h-BN compared with Ni (111)-like surfaces. The observation is in clear contrast to the reported growth of h-BN on Ni(111) in an ultrahigh vacuum environment. The as-grown CVD h-BN films on Ni exhibit a layered structure as revealed by atomic force microscopy (AFM). Thin h-BN layers are found on the Ni domain with a low growth rate. The observation of h-BN growth on various Ni grains may provide insights for the control of thickness, size and morphology of CVD h-BN films.

We synthesized centimeter-scale single- to few-layer graphene (FLG) films via chemical vapor deposition (CVD) on Ni foils. We demonstrates that the precipitation mechanism may not be the only important mechanism in the formation of graphene by CVD in Ni system, and that controlling the cooling rate in the CVD process may not be the appropriate way to control the thickness of graphene films. In addition, we are the first to demonstrate the transfer of centimeter-scale FLG from Ni foil to transparent flexible polyethylene terephthalate substrates via an efficient roll-to-roll process. Comparing to rigid substrates, synthesis of graphene on flexible Ni foil has necessity for the use of a roll-to-roll transfer process., This manuscript was summited to the journal Carbon at Dec. 1, 2009. The revised manuscript was submitted to the journal Carbon at Mar. 24, 2010. This manuscript has been accepted by the journal Carbon at May 2, 2010.

This report shows how the internal transcribed spacer (ITS) region of nuclear ribosomal DNA (rDNA) can be used to determine the species identity of insect cell lines and to distinguish between cell lines derived from closely related insect species. A PCR-RFLP method with the endonucleases HincII and PstI produces restriction fragment profiles that could distinguish between insect cell lines at the species level. Another PCR-based method used three species-specific primer sets, Ly-ITS1/Ly-ITS2, ITS1-1/Ld-ITS1 and Sf9-F2/ITS4, to identify the cell lines from Lymantria xylina, L. dispar and Spodoptera frugiperda, respectively. This method also detected cell-line cross-contaminations (CLCC) with contamination levels as low as 1% (10 cells in a population of 1000 cells) even when the contaminating cells were from a closely related species. Compared with conventional methods used for cell-line identification and CLCC detection, the methods presented here are fast and sensitive and could easily be applied to other cell culture laboratories.

A method for the synthesis of millimeter-scaled graphene films on silicon carbide substrates at low temperatures (750 °C) is presented herein. Ni thin films were coated on a silicon carbide substrate and used to extract the substrate’s carbon atoms under rapid heating. During the cooling stage, the carbon atoms precipitated on the free surface of the Ni and formed single-layer or few-layer graphene. The result shows that the number of graphene layers might be further controlled by appropriate process conditions. In contrast to the epitaxial graphene synthesis on single crystal silicon carbide, the graphene prepared here are continuous over the entire Ni-coated area, and can be stripped from the substrate much more easily for further characterization. The large-scaled, low temperature and transferable features of our method suggest the potential for future graphene-based applications.

The complete genome of the Maruca vitrata nucleopolyhedrovirus (MaviNPV) isolated from the legume pod borer, Maruca vitrata (Lepidoptera: Pyralidae), was sequenced. It was found to be 111 953 bp in length, with an overall 39 % G+C content, and contained 126 open reading frames (ORFs) encoding predicted proteins of over 50 aa. The gene content and gene order of MaviNPV have the highest similarity to those of Autographa californica multiple nucleopolyhedrovirus (AcMNPV) and their shared homologous genes are 100 % collinear. In fact, MaviNPV seems to be a mini-AcMNPV that is native to Taiwan and possesses a smaller genome with fewer auxiliary genes than the AcMNPV type species. Except for one ORF (Mv74), all of the MaviNPV ORFs have homologues in the AcMNPV genome. MaviNPV is the first lepidopteran-specific baculovirus to lack homologues of vfgf and odv-e66. In addition, MaviNPV lacks the baculovirus repeat ORF (bro) gene that corresponds to AcMNPV ORF2. Five homologous regions (hrs) were located within the MaviNPV genome, and these contained a total of 44 imperfect palindromes. Phylogenetic analysis of the whole genome revealed that MaviNPV was separated from the common ancestor of AcMNPV and Bombyx mori nucleopolyhedrovirus before these two viral species diverged from each other. Moreover, replication of MaviNPV in several cell lines and an egfp–MaviNPV infection assay revealed that IPLB-LD-652Y cells are only partially permissive to MaviNPV, which supports our conclusion that MaviNPV is a distinct species of the group I lepidopteran NPVs.

The extended structures of Ag-complexes of the azine based ligands phenyl-2-pyridyl ketone azine (L1) and di-2-pyridyl ketone azine (L2) are reported, and focus is made on the investigation of the influence of the anion and supramolecular interactions on the self-assembly. Using AgNO3, AgClO4 and CF3COOAg salts as starting materials for both ligands in acetonitrile, we observed the formation of the dinuclear complexes [Ag2(L1)2](NO3)2 (1a), [Ag2(L1)2](ClO4)2 (1b), from L1, the tetranuclear complexes [Ag4(L2)2 (NO3)(CH3CN)2](NO3)3 (2a), [Ag4(L2)2(CF3COO)3CH3CN](CF3COO) (2b) and the linear chain polynuclear complex {[Ag3(L2)2] (ClO4)3}n (3) from L2. The X-ray structures show that the molecular geometry depends on the choice of anion. The silver centers have distorted tetrahedral coordination geometry in all the complexes. Weak hydrogen bonding and other interactions result in 2-D and 3-D networks in these complexes.

Here we describe the establishment of a new cell line, NTU-MV, derived from pupal tissues of an economically important pest, the legume pod borer Maruca vitrata. This cell line contained four major cell types: polymorphic cells, round cells, spindle-shaped cells, and comma cells. The doubling time of MV cells in TNM-FH medium supplemented with 8% FBS at 28 °C was 27 h. The chromosome numbers of MV cells varied widely from 16 to 268. Compared to other insect cell lines, the MV cell line produced distinct isozyme patterns with esterase, malate dehydrogenase (MDH), and lactate dehydrogenase (LDH). Confirmation that NTU-MV was derived from M. vitrata was demonstrated by showing that the sequence of the internal transcribed spacer regions (ITS) of the MV cells was 98% identical to that of M. vitrata larvae. Two NTU-MV cell strains, NTU-MV1 and NTU-MV56, were selected based on susceptibility to MaviMNPV (M. vitrata multiple nucleopolyhedrovirus). NTU-MV, MV1, and MV56 cells showed a high susceptibility to MaviMNPV and produced high yields of polyhedra (47–50 OBs/cell, 4 × 107–5.96 × 107 OBs/ml) after 2 weeks of MaviMNPV infection. We conclude that the NTU-MV cell line will be a useful tool for studying MaviMNPV as well as for the mass production of MaviMNPV polyhedra for the biocontrol of M. vitrata.

When a eukaryotic mRNA sequence specifying an amino acid motif known as 2A is directly followed by a proline codon, two nonoverlapping proteins are synthesized. From earlier work, the second protein is known to start with this proline codon and is not created by proteolysis. Here we identify the C-terminal amino acid of an upstream 2A-encoded product from Perina nuda picorna-like virus that is glycine specified by the last codon of the 2A-encoding sequence. This is an example of recoding where 2A promotes unconventional termination after decoding of the glycine codon and continued translation beginning with the 3′ adjacent proline codon.

The controlled coverage of immobilized biomolecules is introduced, illustrating a concept for designing biomaterial surfaces such that the extent of manipulation employed to elicit biological responses is controlled according to density changes in the underlying chemical motifs and the density of immobilized biomolecules.

The reactions of 1,4-di-(N-methyl-2′-pyrrolyl)-2,3-diaza-1,3-butadiene (1), 1,4-di-(6-methyl-2′-pyridyl)-2,3-diaza-1,3-butadiene (2) and 3,6-di-(2′-thienyl)-1,2,4,5-tetrazine (3) with Fe2(CO)9 in toluene, THF and benzene, respectively, yielded various types of hexacarbonyldiiron complexes with five different coordination modes: (1) a complex with two 2-pyrrolylmethylideneamido bridging ligands, 1a, which resulted from N N bond cleavage of ligand 1, (2) a cyclometallated (μ-2,3-η1:η2-pyrrolyl; η1:η1(N)) complex 1b and a cyclometallated (μ-2,3-η1:η2-thienyl; η1:η1(N)) complex 3b, (3) a diaza-bridged complex 3a, (4) an imine-bridged (μ-σ;π-η1:η2-(C,N); η1(Npy)) complex 2a and (5) an imine-bridged ( μ - π - η 1 : η 1 - ( C , N ) ; η 1 ( N py ) ; η 1 ( N py ′ ) ) complex 2b. The molecular structures of the ligands 1 and 3 as well as of the complexes 1a, 2a and 3a have been determined by single-crystal X-ray crystallography.

The reaction of bidentate thienyl Schiff base derivatives, R–Th–C N–Py (R = H, 3-Me, 5-Me, and 5-Br), with copper(I) iodide under mild conditions in acetonitrile yields (i) two one-dimensional coordination polymer chain complexes with alternating six-membered and four-membered metallocycles, [Cu2(C4H3SCHNC5H4N)(μ2-I)(μ3-I)]n, (1) and [Cu2(3-Me-C4H2SCHNC5H4N)(μ2-I)(μ3-I)]n (2), and (ii) two discrete chair-pyramidal shaped tetranuclear complexes, Cu4(5-Me-C4H2SCHNC5H4N)2(μ2-I)2(μ3-I)2 (3) and Cu4(5-Br–C4H2SCHNC5H4N)2(μ2-I)2(μ3-I)2 (4). These complexes are characterized spectrally. The molecular structures of 1, 2, 3 and 4 were established in detail by single-crystal X-ray diffraction analysis. The polymer chain structure of 2 is found to be extended into a two-dimensional supramolecular network through hydrogen-bonded interactions.

A baculovirus has been isolated from infected larvae of the casuarina moth, Lymantria xylina Swinehoe (Lepidoptera: Lymantriidae) in Taiwan. Ultrastructural observation revealed that this virus is a multiple nucleopolyhedrovirus (MNPV), and the name L. xylina MNPV (LyxyMNPV) was proposed. Restriction endonuclease (BamHI, EcoRI, and EcoRV) profiles of LyxyMNPV genome differed from those of other known NPVs. The size of the LyxyMNPV genome was estimated to be 154+/-1.26 kbp (mean+/-SE). The polyhedrin gene is located in the BamHI-D, EcoRI-C, and EcoRV-K fragments of LyxyMNPV genome. The gene organization of the LyxyMNPV EcoRV-K fragment and the phylogenetic analysis based on the polyhedrin gene sequences showed that LyxyMNPV is closely related to the L. dispar MNPV (LdMNPV). Furthermore, a rapid assay method was developed to distinguish LyxyMNPV from LdMNPV based on PCR-RFLP (polymerase chain reaction-restriction fragment length polymorphism) analysis of polyhedrin genes.

The reaction of N-(N′-methyl-2-pyrrolylmethylidene)-2-thienylmethylamine (1) with Fe2(CO)9 in refluxing toluene gives endo cyclometallated iron carbonyl complexes 2 and 5, exo cyclometallated iron carbonyl complex 3, and unexpected iron carbonyl complex 4. Complexes 2, 3, and 5 are geometric isomers. Complex 5 differs from complex 2 in the switch of the original substituent from α to β position of the pyrrolyl ring, and the pyrrolyl ring bridges to the diiron centers in μ-(3,2-η1:η2) coordination mode in stead of μ-(2,3-η1:η2). In complex 4, the pyrrolyl moiety of the original ligand 1 has been displaced by a thienyl group, which comes from the same ligand. Single crystals of 2, 3, and 5 were subjected to the X-ray diffraction analysis. The major product 2 undergoes: (i) thermolysis to recover the original ligand 1; (ii) reduction to form a hydrogenation product, 6, of the original ligand; (iii) substitution to form a monophosphine-substituted complex 7; (iv) chemical as well as electrochemical oxidation to produce a carbonylation product, γ-butyrolactam 8.