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Byline: Yugang. Jiang, Hongyuan. Chen, Meng. Kong, Dong. Sun, Hongguang. Sheng Background: Anastomotic leakage (AL) is one of the most severe and frequent complications occurring after laparoscopic low anterior resection [...]

Prokaryotic Argonautes (pAgos) have been recently used in many nucleic acid biosensing applications but have rarely been used for regulating the isothermal amplification system. Herein, we reported Thermus thermophilusArgonaute (TtAgo)-mediated background-suppressed exponential isothermal amplification (EXPAR) as the first example to explore the binding activity of pAgos toward regulation of the amplification template. It was demonstrated that thermophilic pAgos efficiently eliminated nonspecific hybridization between templates by their binding affinity with the template, resulting in greatly enhancing the specificity of EXPAR. TtAgo-mediated, background-suppressed EXPAR was employed to detect miRNA with a detection limit of 10–15M, which was 1000 times and 100 times more sensitive than that of traditional RT-PCR and EXPAR, respectively. This method further showed good performance in discriminating cancer patients from healthy individuals, indicating its potential for practical clinical applications.

Aluminum-steel hybrid structures have great application prospects in lightweight vehicles. In this study, AA6061-T6 and SS304 with 3 mm thickness and 10 mm lap width were welded-brazed by Cold Metal Transfer process. Both electric parameters and droplets transfer were monitored. An improved discretization method was employed to calculate the equivalent welding parameters. Macro and microstructures were characterized by OM, SEM with EDS and XRD, and the tensile-shear strength, Vickers and nanohardness were measured to evaluate the mechanical properties of the joints. CMT welding process is a short-circuit transfer mode with one pulse one droplet. With the increase in heat input, welding cycle and interfacial layer thickness increased. Al9Fe2Si2and FeAl5or FeAl3were found in the interfacial reaction zone. The intermetallic compounds whose hardness is 1.7 times of SS304 are the main reason for the fracture failure to appear at the interfacial layer.

Hospitals in China are classified into tiers (1, 2 or 3), with the largest (tier 3) having more equipment and specialist staff. Differential health insurance cost-sharing by hospital tier (lower deductibles and higher reimbursement rates in lower tiers) was introduced to reduce overcrowding in higher tier hospitals, promote use of lower tier hospitals, and limit escalating healthcare costs. However, little is known about the effects of differential cost-sharing in health insurance schemes on choice of hospital tiers.

ABSTRACTIntroductionPaclitaxel is a powerful and effective anti-tumor drug with wide clinical application. However, there are still some limitations, including poor water solubility, low specificity, and susceptibility to drug resistance. The peptide-drug conjugates (PDCs) represent a rising class of therapeutic drugs, which combines small-molecule chemotherapeutic drugs with highly flexible peptides through a cleavable or non-cleavable linker. When this strategy is applied, the therapeutic effects of paclitaxel can be improved.Areas coveredIn this review, we discuss the application of the PDCs strategy in paclitaxel, including two parts: the tumor targeting peptide-paclitaxel conjugates and the cell penetrating peptide-paclitaxel conjugates.Expert opinionCombining drugs with multifunctional peptides covalently is an effective strategy for delivering paclitaxel to tumors. Depending on different functional peptides, conjugates can increase the water solubility of paclitaxel, tumor permeability of paclitaxel, the accumulation of paclitaxel in tumor tissues, and enhance the antitumor effect of paclitaxel. In addition, due to the change of cell entry mechanism, partial conjugates can restore the therapeutic activity of paclitaxel against resistant tumors. Notably, in order to better translate into the clinical field in the future, more research should be conducted to ensure the safety and effectiveness of peptide-paclitaxel conjugates.

An important step of somatic variant calling algorithms for deep sequencing data is quantifying the errors. For targeted sequencing in which hotspot mutations are of interest, site-specific error estimation allows more accurate calling. The site-specific error rates are often estimated from a panel of normal samples, which has limited size and is subject to sampling bias and variance. We propose a novel statistical validation method for single-nucleotide variation (SNV) calling based on historical data. The validation method extracts the high-quality reads from the Binary Alignment/Map (BAM) files, finds the negative samples in the data, and builds a statistical model to call individual samples. It is particularly useful in detecting low-frequency variants that may be missed by traditional panel of normal–based SNV methods. The proposed method makes it possible to launch a simple and parallel validation pipeline for SNV calling and improve the detection limit.

The transverse auxiliary magnetic field (TAMF) is employed to eliminate the saddle-shaped weld bead defect in spiral submerged arc welded (SSAW) steel linepipe. The force-balance analysis and numerical simulation of heat and fluid flow in the weld pool elucidate the mechanism why the applied TAMF is able to improve the weld morphology. It is found that optimal matching of welding process parameters and the TAMF intensity is beneficial to obtain satisfactory microstructures and mechanical properties of the welded joints. This work provides an effective solution for overcoming the saddle-shaped formation defect on the inner wall of multi-wire SSAW steel linepipe and enhancing the service performance of long-distance oil and gas transmission pipelines.

Harmless treatment of livestock manure has been a pressing issue due to its contamination of heavy metals and volatilization of nitrogen(N)-containing components during processing. In this paper, the chemical species transformation, leaching characteristics of Cr, Mn, Zn, Cu and conversion of amine N and inorganic N during composting and pyrolysis of swine manure (400°C, 500°C, 600°C and 700°C) were comparatively investigated, and their integrated environmental risk (η) was assessed. According to the ultimate and proximate analysis, pyrolyzed char exhibited better aromaticity and richer functional groups compared with that of compost; Cr, Mn, Zn, Cu were transformed into more stable residual states (F3+F4), and better inhibition of leaching in simulated landfill experiments was shown than compost. However, deamination and cyclocondensation reactions under higher pyrolysis temperatures resulted in N escaping in the form of NH3and HCN. Considering various pollution coefficients, the integrated ecological risk was reduced by 59.24% after 600°C pyrolysis, which is the optimal condition for the minimization of the risk of heavy metal toxicity and N volatilization among all the compost and pyrolysis process.

Excavators are widely used at various construction sites, and they can significantly reduce difficulties during construction and improve construction efficiency. However, conventional excavators still exhibit many shortcomings. In certain construction environments that require precision, the construction accuracy cannot be guaranteed because excavators usually operate in harsh environments. Hence, they can cause potential life hazards to the drivers in certain situations. To address these issues, an excavator automatic control system is developed via retrofitting, modelling, and designing a control program for an excavator. This system can realise three working modes: manual operation, remote control operation, and automatic operation. A test prototype based on the aforementioned concept is developed and relevant experiments are performed. The results under automatic operation mode show that the automatic control system can move the excavator smoothly along the expected trajectory. The fluctuation in the operation velocity is low, and the positioning error to the target position is within 7 cm. Thus, the system can realise the desired control accuracy and satisfy other task design requirements.

ABSTRACTLncRNA Cyclin‐dependent kinase inhibitor 2B antisense RNA 1 (CDKN2B-AS1) plays a role in the progression of multiple cancers like cholangiocarcinoma, osteosarcoma and several gastrointestinal tumors. Few studies have linked its function and mechanism to the development of colorectal cancer (CRC). The expression of CDKN2B-AS1, microRNA (miR)-378b, and cytoplasmic activation/proliferation-associated protein 2 (CAPRIN2) was analyzed in CRC patients and cell lines. The proliferation and migration of CRC cells were evaluated after gain and loss-of function mutations. Interactions between CDKN2B-AS1 and miR-378b, miR-378b and CAPRIN2 were validated by luciferase reporter, RNA pull-down and RNA immunoprecipitation assays. The role of CDKN2B-AS1 was further confirmed in a xenograft mouse model. We found that the expression of CDKN2B-AS1 and CAPRIN2 was upregulated in CRC and they were linked to the poor differentiation and distant metastasis in CRC patients. CDKN2B-AS1 knockdown attenuated while CDKN2B-AS1 overexpression promoted CRC cell proliferation and migration. Notably, the results of Starbase 2.0 database analysis and in vitro experiments demonstrated that CDKN2B-AS1 could interact with miR-378b and regulate its expression. Furthermore, CAPRIN2 acted as a downstream target of CDKN2B-AS1/miR-378b that involved in modulating β-catenin expression in CRC cells. Upregulation of CDKN2B-AS1 contributed to CRC progression via regulating CAPRIN2 expression by binding to miR-378b. Downregulation of CDKN2B-AS1 suppressed tumor growth and Ki-67 staining in vivo that was related to the miR-378b/CAPRIN2 pathway. This study indicated that lncRNA CDKN2B-AS1 promoted the development of CRC through the miR-378b/CAPRIN2/β-catenin axis. CDKN2B-AS1 might serve as a potential and useful target in CRC diagnosis and treatment.

Vascular endothelial growth factor receptor 2 (VEGFR-2) and neuropilin-1 (NRP-1) are two prominent antiangiogenic targets. They are highly expressed on vascular endothelial cells and some tumor cells. Therefore, targeting VEGFR-2 and NRP-1 may be a potential antiangiogenic and antitumor strategy. A7R, a peptide with sequence of Ala-Thr-Trp-Leu-Pro-Pro-Arg that was found by phage display of peptide libraries, can preferentially target VEGFR-2 and NRP-1 and destroy the binding between vascular endothelial growth factor 165 (VEGF165) and VEGFR-2 or NRP-1. This peptide is a new potent inhibitor of tumor angiogenesis and a targeting ligand for cancer therapy. This review describes the discovery, function and mechanism of the action of A7R, and further introduces the applications of A7R in antitumor angiogenic treatments, tumor angiogenesis imaging and targeted drug delivery systems. In this review, strategies to deliver different drugs by A7R-modified liposomes and nanoparticles are highlighted. A7R, a new dual targeting ligand of VEGFR-2 and NRP-1, is expected to have efficient therapeutic or targeting roles in tumor drug delivery.

ABSTRACTBackgroundAccumulating studies demonstrated that resistance of colon cancer (CC) to 5-fluorouracil (5-FU) contributes to adverse prognosis. We investigated how Kruppel-like factor 4 (KLF4) affected 5-FU resistance and autophagy in CC cells.MethodsKLF4 expression and its downstream target gene RAB26 in CC tissues was analyzed by bioinformatics analysis, and the effect of abnormal KLF4 expression on prognoses of CC patients was predicted. Luciferase reporter assay detected the targeted relationship between KLF4 and RAB26. The viability and apoptosis of CC cells were analyzed by CCK-8 and flow cytometry. The formation of intracellular autophagosomes was detected by confocal laser scanning microscopy and immunofluorescence staining. The mRNA and protein levels were assayed by qRT-PCR and western blot. A xenograft animal model was constructed to verify the function of KLF4. Rescue assay was employed to verify whether KLF4/RAB26 could affect 5-FU resistance in CC cells through autophagy.ResultsKLF4 and RAB26 were lowly expressed in CC. KLF4 correlated with patients’ survival. KLF4 was down-regulated in 5-FU resistant CC cells. KLF4 overexpression suppressed the proliferation and 5-FU resistance of CC cells, and inhibited LC3 II/I expression and autophagosome formation. Autophagy activator Rapamycin or sh-RAB26 treatment reversed the impact of KLF4 overexpression on 5-FU resistance. In vivo assay verified that KLF4 inhibited 5-FU resistance in CC cells. Rescue experiments revealed that KLF4 targeted RAB26 to inhibit CC cell autophagy, resulting in decreasing the resistance to 5-FU.ConclusionKLF4 strengthened the sensitivity of CC cells to 5-FU by targeting RAB26 to restrain autophagy pathway.

The damp‐heat (DH) degradation of silicon heterojunction (SHJ) solar modules leads to severe power loss, necessitating superior‐quality encapsulation materials. Herein, it is aimed to investigate the mechanical, thermal, and optical properties of ethylene vinyl acetate (EVA), polyolefin elastomer (POE), and thermoplastic polyolefin (TPO). TPO demonstrates the lowest water vapor transmission rate (WVTR) of only 3.14 g (m2·day)−1, which is approximately seven times lower than that of EVA. The Fourier transform infrared spectroscopy of EVA demonstrates a loss of the carbonyl group, revealing the formation of acetic acid under DH stress, which is not observed in POE and TPO. Both glass/back sheet and glass/glass (G/G) modules show a significant influence of encapsulant material on DH degradation. The maximum output power (Pmax) of the G/TPO/G single‐cell module maintains 96.6% of its initial value after 1000 h DH stress. After sealing the edge, the G/G commercial‐size modules encapsulated with lower WVTR encapsulants display excellent DH reliability, and Pmaxdegrades <4.8% after 3000 h of DH stress. The predicted levelized cost of energy (LCOE) decreases ≈0.11 US cents/(KW h), which boosts additional power generation and illustrates the remarkable potential for the SHJ solar modules meeting the requirements of reliable, sustainable, and low‐LCOE systems. Thermoplastic polyolefin and polyolefin elastomer with very low water vapor transmission use glass/glass photovoltaic modules, making them capable of meeting damp‐heat (DH) testing for 3000 h. DH‐stable silicon heterojunction solar modules can significantly reduce the levelized cost of energy and increase the total power generation, which contribute to the development of solar energy as a sustainable clean energy.

Recent developments in nanopore sequencing have inspired new concepts in precision medicine but limited in throughput. By optically encoding calcium flux from an array of nanopores, parallel measurements from hundreds of nanopores were reported, while lateral drifts of biological nanopores set obstacles for signal processing. In this paper, optical single-channel recording (oSCR) serves to track nanopores with high precision and a general principle of nanopore motion kinetics is quantitatively investigated. By finely adjusting the osmosis-oriented interactions between the lipid/substrate interfaces, motions of nanopores could be controllably restricted. Improved signal-to-noise ratio is observed from motion-restricted nanopores, which is experimentally demonstrated. To systematically evaluate oSCR with asymmetric salt concentrations, a finite element method simulation is established. oSCR with an array of immobilized nanopores suggests new strategies for sequencing DNA by microscopic imaging in high throughput and is widely applicable to the investigation of other transmembrane proteins.

Bead-based assays have drawn more and more attention in biomedical fields. Herein, we proposed a novel approach to achieve multiplex analysis on a single porous hydrogel bead (PHB) with Raman dyes (RDs) encoded core–shell surface-enhanced Raman scattering (SERS) nanotags. Because of the amplified signal of RDs by core–shell metal structure of the nanotag and the high surface area to volume ratio (SVR) of the PHB, the sensitivity and linear dynamic range (LDR) of the as-proposed multiplex analysis method are significantly improved. We anticipate this approach to be widely used in the multiplex assays and biosensors.

Transparent conductive oxide (TCO) film acts as the window layer and carrier transport layer of silicon heterojunction (SHJ) solar cells. The optoelectrical and contact properties of TCO films, as well as the sputtering damage, limit the further efficiency improvement. Herein, the microstructure, morphology, and optoelectrical properties of sputtering‐prepared zinc‐doped indium oxide (IZO) are analyzed. The substrate temperature has a significant impact on the film growth and the cell performance. The IZO film is amorphous when substrate temperature is below 200 °C, while it seems the emergence of nanocrystals with the increased temperature, resulting in the highest conductivity (3070 S cm−1) and carrier mobility (47.9 cm2V−1s−1). In addition, the low carrier concentration and surface potential of IZO promote less optical parasitic absorption and higher work function. The IZO films are applied as the contact layer of SHJ solar cells. An impressive efficiency of 24.02% on an M2‐sized wafer is achieved, indicating great potential for the mass production application after careful optimization. Herein, the microstructure, morphology, and optoelectrical properties of sputtering prepared zinc‐doped indium oxide (IZO) are systematically investigated. The IZO film exhibits high conductivity (3070 S cm−1) and carrier mobility (47.9 cm2V−1s−1). An impressive efficiency of 24.02% on an M2‐sized wafer is achieved, indicating great potential for the mass production application after careful optimization.

Bacteria identification plays a vital role in the field of clinical diagnosis, food industry, and environmental monitoring, which is in great demand of point of care detection methods. In this paper, in order to discriminate the source of nosiheptide product, a plasmonic filter was fabricated to filtrate, capture and identify Streptomycetespores with Surface enhanced Raman Scattering (SERS). Since the plasmonic filter was derived from self-assembled photonic crystal coated with silver, the plasmonic “hot spots” on the filter surface was distributed evenly in a fare good density and the SERS enhancement factor was 7.49 × 107. With this filter, a stain- and PCR-free detection was realized with only 5 μL sample solution and 5 min in a manner of “filtration and measure”. Comparison to traditional Gram stain method and silver-plated nylon filter membrane, the plasmonic filter showed good sensitivity and efficiency in the discrimination of nosiheptide prepared with chemical and biological methods. It is anticipated that this simple SERS detection method with plasmonic filter has promising potentials in food safety, environmental, or clinical applications.

•In-situ generation of electrochemical intermediates during electrospray ionization•The first mass spectrometric identification of picosecond nitrenium/oxenium ions•The first direct observation of the long-sought discrete glycosyl oxocarbenium ion•Cationic intermediates are stabilized in the positively charged microdroplets

A novel disposable paper-based bipolar electrode (BPE) array is fabricated for multiplexed electrochemiluminescence (ECL) detection of pathogenic DNAs. This proposed BPE array device consists of 15 units, each consisting of six sensing cells and two reporting cells patterned using hydrophobic wax. A hairpin structure DNA assembled on the cathodes of BPEs hybridizes with Pt nanoparticles (NPs) labeled probe DNA in the presence of complementary target DNA. The introduction of Pt NPs catalyzes the reduction of dissolved O2at cathodes and induces an enhanced ECL signal from Ru(bpy)32+/tripropylamine (TPrA) at the anodes of BPEs. The dissolved O2lost in reduction reaction could be promptly replenished due to the relatively large contact area of the paper-based cells with air, which ensures the stability of ECL signal. This obtained paper-based BPE array sensor showed excellent performances for the multiplexed analysis of the syphilis (Treponema pallidum) gene, the immunodeficiency virus gene (HIV) and hepatitis B virus gene (HBV).

How to identify whether T1–2 colorectal cancers have lymph nodes metastases pre-op or intra-op is a crucial problem in clinic. The purpose of this study was to evaluate the feasibility of using carbon nanoparticles to track lymph nodes metastases in T1–2 colorectal cancers. A multi-center study was performed between July 2012 and January 2014. Seventy-three patients with T1–2 colorectal cancer identified by pre-op endoscopic ultrasonography (EUS) were recruited. 1 ml carbon nanoparticles suspension was endoscopically injected into the submucosal layer at four points around the site of the primary tumor 1 day before surgery. Laparoscopic radical resection with lymphadenectomy was performed. Sentinel lymph nodes (SLNs) were defined as nodes that were black-dyed by carbon nanoparticles. Pathology confirmed whether lymph nodes have cancer metastases and the SLNs accuracy. SLNs were easily found under laparoscopy. The mean number of SLNs was 3 (range 1–5). All patients had SLNs lying alongside the mesenteric vessel or main arterial vessel. After pathological analysis, 2 patients (9.52 %) had lymph node metastasis in 21 patients with EUS T1 cancers, and 10 patients (19.23 %) had lymph node metastasis in 52 patients with EUS T2 cancers. In two T1 cases with lymph node metastasis, SLNs were positive with 100 % accuracy. In ten T2 cases with lymph node metastasis, SLNs were positive in nine cases. In pathology, carbon nanoparticles were seen in lymphatic vessels, and lymphoid sinus and macrophages in negative SLNs. When SLNs were positive, carbon nanoparticles were seen around cancer cells in lymph nodes. The overall sensitivity, specificity, accuracy of SLNs in T1–2 colorectal cancers were 91.67, 100, 98.63 %, respectively. We demonstrated the feasibility of using carbon nanoparticles to track lymph nodes metastases in T1–2 colorectal cancers. Carbon nanoparticles black-dyed lymph nodes play a role as SLNs in T1–2 colorectal cancers.

Herein, we demonstrate the high-density assembly of Ni–Co hydroxide nanoflakes on conductive carbon nanotube (CNT) network through a simple and rapid chemical precipitation method, presenting a low-cost and high-performance scaffold for pseudosupercapacitor. It is found that the Ni–Co layered double hydroxide (LDH) nanoflakes prefer to proliferate around large-diameter CNTs (diameter > 50 nm), with conductive CNT network well-maintained. Such hierarchical nanostructures show greatly improved specific surface areas compared with bare CNT network and are freestanding without other organic binder, which can be directly employed as a binder-free compact electrode assembly. By optimizing the chemical composition of as-precipitated LDH nanoflakes, the resultant Co0.4Ni0.6(OH)2LDH/CNT composite nanostructures exhibit the largest specific electrochemical capacitance and the best rate performance, with their capacitance up to 1843 F/g under a low current density of 0.5 A/g and maintained at 1231 F/g when the current density is increased 20 times to 10 A/g. Importantly, such hierarchical nanostructures tend to prevent the electrode from severe structural damage and capacity loss during hundreds of charge/discharge under a high rate (2 A/g), ensuring the electrode with high-energy density (51 W h/kg) at power density of 3.3 kW/kg.

The capability of imaging and detecting single DNA molecules is critical in the study, analysis, and applications of DNA. Fluorescence imaging is a widely used method, but it suffers from blinking and photobleaching, and fluorescence tags may block or affect binding sites on DNA. We report on label-free imaging of single DNA molecules with a differential plasmonic imaging technique. The technique produces high contrast images due to the scattering of surface plasmonic waves by the molecules and the removal of background noises and interference patterns, allowing for quantitative analysis of individual DNA molecules. Simulation of the images based on a scattering model shows good agreement with the experiment. We further demonstrate optical mapping of single DNA molecules.

Carbon nanotube (CNT) arrays show great promise in developing anisotropic thermal conductive composites for efficiently dissipating heat from high-power devices along thickness direction. However, CNT arrays are always grown on some substrates and liable to be deformed and broken into pieces during transfer and solution treatment. In the present study, we intentionally synthesized well-crystallized and large-diameter (∼80 nm) multiwalled CNT (MWCNT) arrays by floating catalyst chemical vapor deposition (FCCVD) method. Such arrays provided high packing density and robust structure from collapse and crack formation during post solution treatment and therefore favored to maintain original thermal and electrical conductive paths. Under optimized condition, the CNT arrays can be transferred into flexible composite films. Furthermore, the composite film also exhibited excellent thermal conductivity at 8.2 W/(m·K) along thickness direction. Such robust, flexible, and highly thermal conductive composite film may enable some prospective applications in advanced thermal management.

A novel method has been developed for rapid analysis of the major constituents in Radix Astragaliand honey-processed Astragaluswithin 23 minutes using ultra-performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC/ESI-Q-TOF-MS). Separation analysis was performed on HSS T3 columns with a gradient elution of acetonitrile-water containing 0.1% formic acid at a flow rate of 0.3 mL min−1. Methodology validation showed that the established method had good repeatability (RSD < 8.07%), intra-day precisions (RSD < 4.20%), and stability (RSD < 7.78%). Accurate molecular weight and characteristic fragment ions obtained from Q-TOF-MS provided a reliable criterion for the structural characterization of the major compounds in raw and honey-processed Astragalus. 35 major constituents, including flavonoids, isoflavan, pterocarpan, and saponins, were identified or tentatively characterized by comparing their retention times and MS spectra with those of authentic standards and literature data. Furthermore, quantitative analysis revealed that the content changes of chemical compositions could cause the tonic effect differences between raw and honey-processed Astragalus. The established method is rapid and reliable for simultaneous analysis of constituents in an extract of Radix Astragali. Moreover, this method will simplify further studies of metabolism and pharmacodynamics and will encourage the use of HSS T3 columns in similar traditional Chinese medicine research.

Chemotherapy combined with gene therapy is a promising treatment strategy for breast cancer. However, nonspecific bio-distribution and lack of targeting ability are major challenge for breast cancer therapy. Herein, we investigated whether the anticancer drug 5-fluorouracil (5-FU) and miR-205 could be co-delivered by functionalized PAMAM to the breast cancer cells and realize enhanced therapeutic efficacy relative to mono-treatment. The fifth-poly(amidoamine) (PAMAM) functionalized with human luteinizing hormone releasing hormone (LHRH) and the acetic anhydride was designed as a drug and gene carrier, providing reduced toxicity of the PAMAM and improving the targeting properties of drugs during delivery. The functionalized PAMAM-based 5-FU and miR-205 co-delivery system (LHRH-G5.0NHAC-FUA/miR-205) was fabricated through an amide condensation reaction and an electrostatic self-assembly. Size, zeta potential and the drug loading of the developed co-delivery system were 238.4 ± 2.3 nm, 4.40 ± 0.23 mV and 40.76%, respectively. Cytotoxicity studies showed a greater antiproliferation effect of LHRH-G5.0NHAC-FUA/miR-205 than its nontargeted counterpart. In vivostudies exhibited a higher antitumor efficiency of LHRH-G5.0NHAC-FUA/miR-205 than its nontargeted counterpart. Therefore, the developed co-delivery system is a promising platform for the efficient co-delivery of miR-205 and 5-FU and shows good anti-breast cancer effect.

MnO2has been widely studied as the pseudo-capactive electrode material of high-performance supercapacitors for its large operating voltage, low cost, and environmental friendliness. However, it suffers from low conductivity and being hardly handle as the electrodes of supercapacitors especially with flexibility, which largely limit its electrochemical performance and application. Herein, we report a novel ternary composite paper composed of reduced graphene sheet (GR)-patched carbon nanotube (CNT)/MnO2, which has controllable structures and prominent electrochemical properties for a flexible electrode of the supercapacitor. The composite paper was prepared by electrochemical deposition of MnO2on a flexible CNT paper and further adsorption of GR on its surface to enhance the surface conductivity of the electrode and prohibit MnO2nanospheres from detaching with the electrode. The presence of GR was found remarkably effective in enhancing the initial electrochemical capacitance of the composite paper from 280 F/g to 486.6 F/g. Furthermore, it ensures the stability of the capacitance after a long period of charge/discharge cycles. A flexible CNT/polyaniline/CNT/MnO2/GR asymmetric supercapacitor was assembled with this composite paper as an electrode and aqueous electrolyte gel as the separator. Its operating voltage reached 1.6 V, with an energy density at 24.8 Wh/kg. Such a composite structure derived from a multiscale assembly can offer not only a robust scaffold loading MnO2nanospheres but also a conductive network for efficient ionic and electronic transport; thus, it is potentially promising as a novel electrode architecture for high-performance flexible energy storage devices.

Preparation of strong, flexible, and multifunctional carbon-based films has attracted considerable interest not only in fundamental research areas but also for industrial applications. We report a binder-free, ultrastrong, and foldable carbon nanotube (CNT) film using aligned few-walled nanotube sheets drawn from spinnable nanotube arrays. The film exhibits tensile strengths up to ∼2 GPa and a Young’s modulus up to ∼90 GPa, which is markedly superior to other types of carbon-based films reported, including commercial graphite foils, buckypapers, and graphene-related papers. The film can bear severe bending (even being folded) and shows good structure integrity and negligible change in electric conductivity. The unique structure of the CNT film (good nanotube alignment, high packing density) provides the film with direct and efficient transport paths for electricity. As a flexible charge collector, it favors a magnesium oxide coating to exhibit high charge/discharge rate stability and an excellent electrochemical capacitance close to its theoretical value.

Abstract: Nanofluidics is a recent appearing research field, introduced in 1995 as an analogue of the field of microfluidics, and has been becoming popular in the past few years. The proximity of the channel dimension, the Debye length, and the size of biomolecules such as DNA and proteins gives the unique features of nanofluidic devices. Of various unique properties of the nanofluidics, mass transport in nanochannel plays determining roles in fundamental reaches and practical applications of nanofluidic device. Thus, much work including numerical and experimental researches has been performed to investigate the mass transport behaviors in nanofluidic devices. This review summarizes the fabrication technologies for nanofluidic devices, the mass transport behaviors in nanochannel, and their applications in bioanalysis. The main focus will be laid on the effects of nanochannel size and surface charge on mass transport including electrokinetic transport of charged analytes, diffusion of electric neutral molecules, ionic current rectification, concentration polarization, nonlinear electrokinetic flow at the micro-nanofluidic interfaces.

Carbon nanotube (CNT) buckypaper, which has large specific surface area and tunable network structures, shows great potential in the application of heat dissipation for high power electronic devices. In this article, we report that the heat conduction in a buckypaper depends greatly on CNT network formation, in which CNT structures, lengths, and orientations are important issues. The buckypaper composed of multiwalled CNTs with large diameter (around 50 nm) and suitable length (1–10 μm) shows lower thermal impedance compared with those made by longer CNTs with smaller diameter. The thermal impedance of such buckypapers can be reduced to 0.27 cm2·K/W, lower than that of commercialized graphite foil and thermal grease. Thus, the buckypaper may serve as a promising candidate for advanced thermal interface materials. Detailed structural characterization indicates that the three-dimensional networks of buckypapers, with CNT orientations perpendicular to the surfaces, result in both the reduction of thermal contact resistance and the enhancement of heat conduction along the thickness.

Abstract: A versatile DNA recognition system using cadmium sulfide nanoparticles (CdS NPs) as labels was proposed for ultrasensitive detection of specific sequence DNA based on target recycling. This strategy utilized the magnetic particles (MNPs) for the immobilization of linker DNA and CdS NPs and the subsequent target DNA hybridization. Using the unique characteristic of nicking endonuclease for cutting one specific strand of double strand DNA (ds DNA), the linker DNA could be transected and the target DNA could be liberated for re-hybridization and hence the amount of released CdS NPs was enhanced. Due to the advantage of the MNPs and signal amplification from the target recycling, the analyte DNA could be detected by the square-wave stripping voltammetry (SWV) in a wide linear range from 0.4 fM to 100 fM with the detection limit down to 0.08 fM. The proposed DNA detection strategy possesses high sensitivity, satisfactory reproducibility and excellent stability, which might have potential in other DNA biological assays.

A composite film with switchable transparency is fabricated by sandwiching a carbon nanotube (CNT) sheet within polyurethane (PU) films. The introduction of CNTs not only makes the composite film electrically conductive but also induces a rapid crystal melting of soft segments in the PU. As a result, the film can be switched from opaque to transparent in just several seconds after turning on voltage, and reversed back to opaque after turning off voltage. The film also possesses several other attractive properties, including excellent flexibility, low energy consumption, switching speed insensitivity to ambient temperature, and easy coloration, which make the film promising for a wide variety of practical applications.

Abstract: A core-shell Rhodamine B-doped SiO2 nanoparticle was synthesized and its fluorescent intensity was found to be 1000 times higher than that of individual Rhodamine B molecule. The doped nanoparticles were further conjugated with streptavidin and the resulting nanoparticles were used in the detection of reverse-phase protein microarrays, in which human IgG of various concentrations was first immobilized on aldehyde-modified glass slides and then biotinlyated goat anti human IgG as well as the labeled nanoparticles were sequentially conjugated. The calibration curve is linear over the range from 800 fg to 500 pg and the limit of detection is 100 fg, which is 8 times lower than that of streptavidin-labeled Cy3 fluorescent dyes. The dye-doped SiO2 nanoparticles show potentials for the protein array detection.

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The direct electron transfer and electrocatalysis of horseradish peroxidase (HRP) immobilized on hexagonal mesoporous silicas (HMS) matrix was studied. The interaction between HRP and HMS was examined by using Fourier transform infrared spectroscopy, nitrogen adsorption isotherms and electrochemical methods. The immobilized HRP at a modified glassy carbon electrode showed a good direct electrochemical behavior, which depended on the specific properties of the HMS. Two couples of redox peaks corresponding to Fe(III) to Fe(II) conversion of the HRP intercalated in the mesopores and adsorbed on the external surface of the HMS were observed with the formal potentials of −0.315 and −0.161 V in 0.1 M pH 7.0 PBS, respectively. The amount of HRP intercalated in the mesopores of HMS proved to be related to the pore size. The HRP intercalated in the mesopores showed a surface controlled electrode process with a single proton transfer. The immobilized HRP displayed an excellent electrocatalytic response to the reduction of hydrogen peroxide (H2O2) without the aid of an electron mediator. The HMS provided a novel matrix for protein immobilization and direct electron transfer study of the immobilized protein.

A reliable method is presented for the chiral separation of three basic drugs (mexiletine, chlorpheniramine and propranolol) with serum albumins (human and porcine, HSA and PSA) as chiral selectors by capillary electrophoresis in combination with the partial filling technique. Based on the systematic optimization of operation variables, the chiral separation of mexiletine, chlorpheniramine and propranolol was achieved in the pH 7.4 phosphate buffer by using HSA, PSA and PSA as selectors, respectively. The chiral recognition ability of HSA and PSA was compared. HSA and PSA show a different chiral recognition ability for each of the three drugs. In addition, the association constants between enantiomeric drugs and proteins were determined to be 2.00 and 3.80 × 102M–1for mexiletine and HSA, 0.59 and 1.12 × 103M–1for chlorpheniramine and PSA, and 0.87 and 1.42 × 103M–1for propranolol and PSA. The method for the chiral separation and determination of association constants possesses the advantages of simple performance, effective avoiding of the interference of the UV detection from protein, and lowering of the reagent consumption.

Potentiodynamic techniques were used for the direct electrodeposition of Prussian blue nano-clusters from an acidic solution of ferricyanide. Electrochemical, EQCM, IR, AFM, and UV/vis measurements were carried out to characterize deposited nano-sized Prussian blue and to explore the formation mechanism. Results showed that ferricyanide could partially dissociate to free ferric and cyanide ions. The driving force of this dissociation is the formation of PB and the evolution of HCN. The optimal potential window for the potentiodynamic formation of PB from an acidic solution (pH 1.6) is between -0.5 V and 0.4 V. In addition, the influence of surface adsorption of CN - ions on the formation of PB was discussed.

A voltammetric enzyme-linked immunoassay based on new system of m -aminophenol (MAP)-H 2 O 2 -horseradish peroxidase (HRP) has firstly been developed and used for the detection of HRP, labelled HRP and ferritin in human serum. HRP or labelled HRP catalyzes the oxidation reaction of MAP with H 2 O 2 , the product of which produces a sensitive voltammetric peak at potential of −0.46 V (vs. SCE) in Britton-Robinson (BR) buffer solution. By using this voltammetric peak, HRP can be measured with a detection limit of 9.5×10 mU/l and a linear range of 2.5-2.5×10 mU/l. The detection limit to ferritin is 0.25 ng/ml and the linear range 0.25-320 ng/ml. The processes of the electro-reduction of the product of the enzyme-catalyzed reaction have been investigated in detail.

A voltammetric enzyme‐linked immunoassay based on a new system of o‐aminophenol (OAP)‐H2O2‐horseradish peroxidase (HRP) has been developed and used for detection of HRP, labelled HRP and southern bean mosaic virus (SBMV). HRP or labelled HRP catalyzes the oxidation reaction of OAP with H2O2, the product of which produces a sensitive voltammetric peak at a potential of –0.43 V (vs. SCE) in Britton‐Robinson (BR) buffer solution. By using this voltammetric peak, HRP can be measured with a detection limit of 6.0×10–13g/mL and a linear range of 1.0×10–12–4.0×10–9g/mL. The southern bean mosaic virus (SBMV) has successfully been detected, and satisfactory results have been obtained.

A method for the determination of α‐1‐fetoprotein (AFP) in human serum by using a horseradish peroxidase (HRP) label in an enzyme‐linked immunosorbent assay (ELISA) is proposed. The method is based on the electrochemical determination of enzymatic reaction product with differential pulse voltammetry at a gold disk electrode. The assay consists of two successive steps. The first step is a conventional HRP‐mediated ELISA for the formation of electroactive 2,2′‐diaminoazobenzene by means of the o‐phenylenediamine–H2O2–HRP system. At the second step, 2,2′‐diaminoazobenzene exhibits a sensitive voltammetric response at −0.19 V in pH 2.0 PBS. The peak current is proportional to the concentration of AFP in the range of 0.5–400 ng/mL (R=0.9993) under optimum conditions. The sensitivity of this method is higher than that of the traditional spectrophotometric ELISA procedure. The proposed methodhas been applied to the clinical determination of AFP in human serum with satisfactory precision and accuracy.

ABSTRACTThe modified glassy carbon electrodes prepared by simultaneously covering with [Os(bpy)2(PVP)10Cl]+redox polymer and Nafion film exhibited excellent electrocatalytic activity for the oxidation of dopamine (DA). Dual linear regions between 1.0x10−8-1.8x10−5M and 1.8x10−5-4.0x10−4M with correlation coefficients of 0.998 and 0.995, respectively, were obtained for log-log plots of catalytic current versus DA concentration. The detection limit for DA determination was ca. 5 nM with 3σ. The dual-film modified electrodes eliminated efficiently the interference from AA presence in a 1000-fold concentration ratio and showed excellent reproducibility for the determination of DA. The modified electrodes have been used to determine DA concentration with both cyclic voltammetric and chronoamperometric techniques. Electrocatalytic kinetics have been studied using a rotating disk electrode. Both the addition of Nafion film and an increase in DA concentration resulted in a decrease in the electrocatalytic rate constant. An apparent Michaelis-Menten constant of 1.3 mM and maximum catalytic current of 88μA were evaluated from the chronoamperometric measurements.

ABSTRACTThree voltammetric enzyme-linked immunoassays based on new systems of o-, m- and p-aminophenol-H2O2-horseradish peroxidase (HRP) have been developed and used for the detection of α-fetoprotein (α FP) in human serum. HRP or labelled HRP catalyzes the oxidation reactions of o-, m- and p-aminophenol with H2O2, the products of which produce three sensitive voltammetric peaks at potentials of −0.87 V, −0.46 V and −0.45 V (vs. SCE) in Britton-Robinson (BR) buffer solution, respectively. By using these voltammetric peaks, the detection limits of α FP are 1.25 ng/mL, 0.5 ng/mL and 0.2 ng/mL, respectively, and the linear ranges 1.25-400 ng/mL, 0.5-400 ng/mL and 0.2-400 ng/mL, respectively. The detection limits of α FP with these methods are lower than that with the enzyme-linked immunosorbent spectrophotometric assay (ELISA).

ABSTRACTPreviously purified cytochrome c can exhibit a current response at a silver electrode and the electron transfer reaction can be promoted by dodecyl benzene sodium sulfonate. Addition of the promoter to the protein solution, the peak potentials of the protein are unchanged, but the peak currents increase sharply. Experimental results reveal that the peak current is linearly proportional to the protein concentration in the range of 0.08 – 1.2 μmol/L. The detection limit is 0.05 μmol/L. In addition, commercial samples as received can also give good redox waves after the macromolecules are acted on by the promoter. So the current response of the protein can be widely used.

A new amperometric electrode for the assay of lactate dehydrogenase (LDH) is prepared by modifying a nanometer—sized microband gold electrode with nickel hexacyanoferrate. The amperometric determination bases on electrochemically detecting NADH produced by the enzymatic reaction of lactate with NAD+ under the catalysis of LDH. The modified electrode can sensitively detect LDH at +0.55V vs. SCE with a linear response in the range of 10U / mL to 350U / mL under optimum conditions.

A nanometer‐sized (88 mm) microband gold electrode for glucose detection is described. These noble metal ultramicrosensors are prepared by electrochemical copolymerization of o‐phenylenediamide (PDA) and glucose oxidase at the nanometer‐sized electrodes. Electropolymerization conditions of PDA at the microband surface are optimized. The current can rapidly (3s) reach a steady value upon the potential step from 0 to +0.6 V without stirring the solution. The permselectivity characteristics of polymer can eliminate the interference of ascorbic acid. The amperometric response to glucose shows a linear relation in the range of 0.5 mM to about 10 mM with the correlation coefficient of 0.9993. With further increasing of glucose concentration an obvious Michaelis‐Menten's response can be observed. The maximum steady current density is ca. 4.4 ± 0.2 mA/cm2and the apparent Michaelis‐Menten constant is 21.1 ± 0.2 mM.

L-cysteine can be modified onto a silver electrode by covalent binding through the sulphur to give very stable and long-lived chemically modified electrodes(CMEs). Hemoglobin(Hb) exhibits an excellent voltammetric response at the resulting CMEs. Linear sweep voltammetric(LSV) measurements of Hb on the CMEs reveal the existence of a linear relationship between the cathodic peak current and the concentration of Hb in the range of 5 X 10-7 - 1 X 10-5 mol/L. The detection limit is about 2 X 10-7 mol/L. The relative standard deviation of results is 4.5% for 10 successive determinations at 2 X 10-6 mol/L. Other proteins and chemicals present in samples do not interfere in the assay.

The hemoglobin concentration in diluted whole blood has been amperometrically measured using a toluidine blue O covalently modified microcylinder carbon fiber electrode. The modified electrode was prepared by modifying the surface of carbon fiber by cyclic voltammetric oxidation to form a lot of -COOH groups, and then covalently linking toluidine blue O (TBO) by acylation. The surface morphology and stability of the TBO modified electrode are discussed. The electrochemical behaviour of the modified electrode was studied by cyclic voltammetry. The number of H+ participating in the surface electrode process and some kinetic parameters in various pH solutions were determined. The TBO modified microelectrode showed significant electrocatalytic activity for the oxidation of hemoglobin(HB) in pH 5.4 solution. The amperometric response to HB increased linearly with increasing concentration from 8.0x10-6 to 8.0x10-4 M. The obtained HB concentration correlated well with that obtained using a reference procedure.

AbstractCaptopril, 1-[(2S)-3-mercapto-2-methyl-1-oxopropyl]-L-Proline, can be deposited onto a silver electrode by a covalent bonding method to give a long-lived and stable chemically modified electrode(CME). Since the CME is prepared with a reaction between captopril and the substrate silver, the CME being prepared by this method is very stable. Furthermore, Hemoglobin(Hb) exhibits excellent voltammetric response at the modified electrode. Differential pulse voltammetric(DPV) measurements of the protein with this CME reveal the existence of a linear relationship between the anodic peak current and the concentration of Hb in the range of 2×10−6∼ 5×10−5mol/L. The detection limit is 8×10−7mol/L and the relative standard deviation of results is 5% for 6 successive determinations at 2×10-5mol/L. The determination of Hb for a real example is carried out.

AbstractPreliminary studies concerning the structural characterization of inclusional complexation have been carried out between barbiturate and β-cyclodextrin on silver surface by using infrared reflection absorption spectroscopy (IRRAS). The results not only provide convincing evidence for the complex formation but also reveal special structural features of the supramolecules oriented on Ag surface.

Diabetic ischemic wound treatment remains a critical clinical challenge. Neovascularization plays a significant role in wound healing during all stages of the tissue repair process. Strategies that enhance angiogenesis and neovascularization and improve ischemic pathology may promote the healing of poor wounds, particularly diabetic wounds in highly ischemic conditions. We previously identified a cyclic peptide LXW7 that specifically binds to integrin αvβ3 on endothelial progenitor cells (EPCs) and endothelial cells (ECs), activates vascular endothelial growth factor (VEGF) receptors, and promotes EC growth and maturation. In this study, we designed and synthesized a multi-functional pro-angiogenic molecule by grafting LXW7 and collagen-binding peptides (SILY) to a dermatan sulfate (DS) glycosaminoglycan backbone, named LXW7-DS-SILY, and further employed this multi-functional molecule to functionalize collagen-based extracellular matrix (ECM) scaffolds. We confirmed that LXW7-DS-SILY modification significantly promoted EPC attachment and growth on the ECM scaffolds in vitroand supported EPC survival in vivoin the ischemic environment. When applied in an established Zucker Diabetic Fatty (ZDF) rat ischemic skin flap model, LXW7-DS-SILY-functionalized ECM scaffolds loaded with EPCs significantly improved wound healing, enhanced neovascularization and modulated collagen fibrillogenesis in the ischemic environment. Altogether, this study provides a promising novel treatment to accelerate diabetic ischemic wound healing, thereby reducing limb amputation and mortality of diabetic patients.

Single-molecule localization allows determining the underlying biological and biochemical processes and promotes the development of super-resolution imaging techniques. Here, we present an optical technique of tracking the motion of a single nanoparticle linked to a substrate via a biomolecule tether to reveal the localization of single biomolecules and the transient states of single nanoparticle switching between specific binding pairs. The affinities, steric hindrance, and conformational variation of a single-molecule binding pair uncover the dynamic details and intrinsic mechanism of binding processes with high specificity and accuracy (a few nanometers). The application of tracking motions of single soft liposomes on different modified surfaces was further demonstrated, which revealed the characteristic behavior related to surface chemistry. Our results show that the trajectory of nanoscale liposomes loaded with small-drug molecules is linked to the compositional inhomogeneity, which provides a route for thorough comprehension of the fundamental biotechnological process.