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Recent advances in therapeutic modulation of human microbiota have driven new efforts to engineer living microbial medicines using synthetic biology. However, a long-standing challenge for live bacterial therapies is balancing the high dose required to achieve robust efficacy with the potential for sepsis. Here, we developed a genetically encoded microbial encapsulation system with tunable and dynamic expression of surface capsular polysaccharides to enhance therapeutic delivery. Following a synthetic small RNA knockdown screen of the capsular biosynthesis pathway, we constructed synthetic gene circuits that regulate bacterial encapsulation based on sensing the levels of environmental inducer, bacterial density, and blood pH. The induced encapsulation system enabled tunable immunogenicity and survivability of the probiotic Escherichia coli, resulting in increased maximum tolerated dose and enhanced efficacy in murine cancer models. Furthermore, triggering in situ encapsulation was found to increase microbial translocation between mouse tumors, leading to efficacy in distal tumors. The programmable encapsulation system demonstrates a new approach to control microbial therapeutic profiles in vivo using synthetic biology.

A variety of chemical sensing materials and procedures for conveniently detecting mercuric ion (II) (Hg2+) have been extensively explored. The detection challenges for accomplishing a simple, fast, and low investment procedure at the ultrasensitive level are ongoing. Herein we report a quadrillionth level for detecting Hg2+ by the surface-enhanced Raman scattering (SERS) technique. There is an interaction of silver nanoparticles decorated on a zinc-oxide tetrapod structure and coated on FTO glass (Ag@ZnO-FTO) with an organic ligand. 4,4′-Dipyridyl (DPy) performed as being chemisorbed by Ag nanoparticles interacting with a pyridine ring to produce plasmonic hot spots for SERS. The morphology of the surface and porous structure of the tetrapod becomes the powerful platform for enhanced SERS performance of DPy detection. In the absence of the augmentative electrolyte, the enhancement factor for DPy is more than 107. The inhibiting of the aggregation between Ag and DPy was present following the appearance of Hg2+, demonstrated by the quenching of the SERS signal from the DPy molecules. The capability to reproduce and the selectivity of the sensing by DPy were both demonstrated. In addition, the applications for detecting Hg2+ in natural water and beverages were successfully detected. These results demonstrated the SERS sensors had the potential for detecting Hg2+ in practical use.

In this study we prepared six types of carbon nanodots (CNDs) from natural plant materials – through carbonization of two species of bamboo (Bamboo-I, Bamboo-II) and one type of wood (Wood), and through hydrothermal processing of the stem and root of the herb Mahonia oiwakensis Hayata (MO) and of the agricultural waste of two species of pineapple root (PA, PB). The resulting CNDs were spherical with dimensions on the nanoscale (3–7 nm); furthermore, CND-Bamboo I, CND-Wood, CND-Bamboo II, CND-MO, CND-PA, and CND-PB displayed fluorescence quantum yields of 9.63, 12.34, 0.90, 10.86, 0.35, and 0.71%, respectively. X-ray diffraction revealed that the carbon nanostructures possessed somewhat ordered and disordered lattices, as evidenced by broad signals at values of 2θ between 20 and 30°. CND-Bamboo I, CND-Wood, and CND-Bamboo II were obtained in yields of 2–3%; CND-MO, CND-PA, and CND-PB were obtained in yields of 17.64, 9.36, and 22.47%, respectively. Cytotoxicity assays for mouse macrophage RAW264.7 cells treated with the six types of CNDs and a commercial sample of Ag nanoparticles (NPs) revealed that each of our CNDs provided a cell viability of 90% at 2000 μg mL−1, whereas it was only 20% after treatment with the Ag NPs at 62.5 μg mL−1. The six types of CNDs also displayed low cytotoxicity toward human keratinocyte HacaT cells, human MCF-7 breast cancer cells, and HT-29 colon adenocarcinoma cells when treated at 500 μg mL−1. Moreover, confocal microscopic cell imaging revealed that the fluorescent CND-Bamboo I particles were located on the MCF-7 cell membrane and inside the cells after treatment for 6 and 24 h, respectively. We have thoroughly investigated the photoluminescence properties and carbon nanostructures of these highly dispersed CNDs. Because of the facile green synthesis of these six types of CNDs and their sourcing from abundant natural plants, herbs, and agriculture waste, these materials provide a cost-effective method, with low cytotoxicity and stable fluorescence, for biolabeling and for developing cell nanocarriers.

Biologically and environmentally resorbable electronic devices support application possibilities that cannot be addressed with conventional technologies. This paper presents highly conductive, water-soluble composites that can be printed to form contacts, interconnects, antennas, and other important features that are essential to nearly all systems of this type. An optimized material formulation involves in situ polymerization to yield a polyanhydride containing a dispersion of molybdenum microparticles at appropriate concentrations. Comparisons of essential physical and electrical properties of these materials to those of composites formed with other polymers and other metal microparticles reveal the relevant considerations. Various functional demonstrations of screen-printed test structures and devices illustrate the suitability of these conductive inks for use in water-soluble electronic devices. A key advantage of the material introduced here compared to alternatives is its ability to maintain conductance over significant periods of time while immersed in relevant aqueous solutions. Studies involving live animal models establish the biocompatibility.

One new xanthone, (±) garciesculenxanthone C (1), two new biphenyls, garciesculenbiphenyls A (2) and B (3), together with two known compounds, doitungbiphenyl B (4) and morusignin D (5), were isolated from Garcinia esculenta. The structures of new compounds were elucidated by spectroscopic analysis, and the absolute configuration of (±) garciesculenxanthone C (1) was assigned by a modified Mosher′s method. All isolates were evaluated for their antistaphylococcal activities against Staphylococcus aureus Newman, USA300 LAC, USA400 MW2, and Mu50 strains. Among these, (±) garciesculenxanthone C (1) showed the best antistaphylococcal activity, and its effect was determined to be bactericidal by time-kill experiment.

The circular dichroism (CD) performance of conjugated gammadion structure on the end facet of silicon waveguide in the mid-infrared regime is investigated theoretically. By engineering the orientation of the structure, the sign and value of its CD spectrum can be changed. For a fixed gammadion structure, different CD values can be obtained not only by changing the excitation wavelength but the excitation waveguide mode. This finding potentially provides an extra degree of freedom to design integrated chiral photonics chips.

Fructus Psoraleae (FP) causes cholestatic liver injury; however, its main toxic constituents that are responsible for causing hepatotoxicity remained undetermined in previous studies. In the present study, psoralen and isopsoralen, the two main constituents of FP, were administered orally to rats (80 and 40 mg/kg, respectively) and mice (320 and 160 mg/kg, respectively) for 28 days, followed by biochemical and histopathological examinations to evaluate their hepatotoxicity. The results showed that psoralen and isopsoralen could induce the toxic reactions of liver and other organs in rats, while mice were not sensitive to these two compounds. Furthermore, the corresponding results indicated that administration of psoralen and isopsoralen repressed the expression of CYP7A1, BSEP, MRP2 and SULT2A1 and increased the expression of FXR and MRP3 in the rat liver. In summary, the toxic reactions of psoralen and isopsoralen are different in different species. In this study, multiple organ toxicity, such as cholestatic liver injury, occurs in rats, but not in mice. Psoralen and isopsoralen are the two main toxic constituents of FP. In addition, psoralen and isopsoralen cause liver injury, possibly through inhibiting bile acid excretion in the liver, leading to the accumulation of toxin in hepatocytes.

Background AMP-activated protein kinase (AMPK), a principal intracellular energy sensor, plays a crucial role in cell growth, proliferation, apoptosis and autophagy. Imiquimod (IMQ) directly exhibits anti-tumor activity through the induction of apoptosis and autophagic cell death. Objective To evaluate the role of AMPK in IMQ-induced apoptosis and autophagy. Methods The phosphorylation of AMPK and its substrates was detected by immunoblotting. ATP contents were analyzed by an ATP bioluminescence assay. The upstream signaling for AMPK activation was dissected by examination of TLR7/8 expression, over-expression of TLR7/8, the addition of AMPK kinase inhibitors, and the genetic silencing of Myd88 and LKB1. The role of AMPK activation in IMQ-induced autophagy and apoptosis was assessed by inhibiting AMPK, genetically silencing AMPK and over-expressing AMPK dominant-negative mutants. Autophagy and apoptosis were evaluated by a DNA content assay, immunoblotting, EGFP-LC3 puncta detection and acridine orange staining. Results IMQ could activate AMPK and autophagy in cancer cells not expressing TLR7/8. IMQ caused ATP depletion and induced LKB1-mediated AMPK activation. The down-regulation of AMPK activity via pharmacological inhibition and genetic silencing resulted in reduced IMQ-induced apoptosis but did not influence autophagy, and this rescue effect was associated with the retention of translation factor activity and anti-apoptotic Bcl-2 family member Mcl-1 protein expression levels. Conclusion IMQ induces AMPK activation independent of TLR7/8 expression, resulting in translation inhibition and subsequent apoptosis through ATP depletion and LKB1 signaling, in skin tumor cells.

Graphical abstractDisplay Omitted HighlightsThe intrinsic parameter fluctuation is studied for the 16-nm-gate TiN/HfO2 bulk FinFETs.The fluctuation includes the random discrete dopant, the random interface trap, and the random work function, simultaneously.The full 3D simulated threshold voltage fluctuation is 26.2mV for the N-type bulk FinFET.The statistical sum of these fluctuations is 9.5% overestimation because independence assumption on these random variables is invalid.Compared with the planar MOSFET, more than 50% reduction on the threshold voltage fluctuation is estimated. In this work, based on the experimentally calibrated 3D device simulation, we for the first time estimate the impact of intrinsic parameter fluctuation on the electrical characteristic of 16-nm-gate TiN/HfO2 bulk FinFETs. The sources of intrinsic parameter fluctuation include the random discrete dopants, interface traps and work function differences, simultaneously. The full 3D simulated threshold voltage fluctuation, induced by the aforementioned random sources simultaneously, is 26.2mV for the N-type bulk FinFET (and is 55.5mV for the planar N-MOSFET). For the N-type bulk FinFET, the statistical sum of these fluctuations is 9.5% (and is 12.3% for the planar device) overestimation, compared with the full 3D simulation. One of the main reasons is the independence assumption on these random variables is destroyed owing to interactions to different extents among RDs, ITs and WKs. The coupled surface potentials cannot be simply estimated by using their statistical sum of individual random source. Under the same threshold voltage, compared with the result of the planar MOSFETs, more than 50% reduction on the threshold voltage fluctuation of the explored bulk FinFETs is observed owing to the benefit of 3D structural nature.

In this paper, the dynamic characteristics of the novel amorphous silicon thin-film transistor gate drive circuit applied on a 10.1-in. panel are optimized by using a multi-objective optimization method. Simultaneously, considering the multiple electrical characteristics of the tested circuit, the achieved results reveal interesting properties as well as good sensitivity of the optimized design parameters. The optimal specifications not only suppress the output ripple, but also reduce the dynamic and static power consumptions.

In this study, effects of the thickness of a low temperature (LT) buffer and impurity incorporation on the characteristics of Nitrogen (N)-polar GaN are investigated. By using either a nitridation or thermal annealing step before the deposition of a LT buffer, three N-polar GaN samples with different thicknesses of LT buffer and different impurity incorporations are prepared. It is found that the sample with the thinnest LT buffer and a nitridation step proves to be the best in terms of a fewer impurity incorporations, strong PL intensity, fast mobility, small biaxial strain, and smooth surface. As the temperature increases at ~10 K, the apparent donor-acceptor-pair band is responsible for the decreasing integral intensity of the band-to-band emission peak. In addition, the thermal annealing of the sapphire substrates may cause more impurity incorporation around the HT-GaN/LT-GaN/sapphire interfacial regions, which in turn may result in a lower carrier mobility, larger biaxial strain, larger bandgap shift, and stronger yellow luminescence. By using a nitridation step, both a thinner LT buffer and less impurity incorporation are beneficial to obtaining a high quality N-polar GaN.

In this study, we investigated the effects of different heating processes on the structural, electrical and chemical properties of ZnO:Ga (GZO) films from the viewpoint of nucleation and growth behaviors. An infrared heating furnace and a traditional tube furnace were employed for the homogeneous and heterogeneous nucleation of GZO films. XRD patterns demonstrated that the preferential growth orientation of both kinds of GZO films is still the (002) direction. XPS data implied that the infrared heating process enables more uniform distribution of the dopant material and retards the oxidization of gallium in grain boundary areas. At the same time, the textured crystallite might provide a free tunnel for oxygen diffusion. Thus, the activation of free charge carriers could be more efficient when the GZO films were annealed under vacuum. As a result, the samples annealed by the infrared heating furnace had a noticeably high carrier concentration. Although the mobility was slightly smaller than that of the samples annealed by the tube furnace, film resistivity dropped obviously in general.

Using different precursor preparation, heating methods, and initial layers, this work investigated the relation between the micro-structural and electrical properties of ZnO:Al (AZO) films prepared by sol–gel method on glass and silicon substrates. It was found that adding monoethanolamine (MEA), using initial layers, or an intentionally produced steep temperature gradient obviously promoted film growth along the (002) direction. However, the carrier mobility rose only a little while the carrier concentration was not affected or even reduced. Generally speaking, the film conductivity was not evidently improved. It could be concluded that all three methods are advantageous for enhancing the crystallographic quality and therefore the mobility of the AZO films, but the major reason for the poor conductivity of the sol–gel derived ZnO films was the low activation of the dopant, which is the key factor for further improvements and should be solved first.

In this study, we investigated the influences of gallium concentration and a rapid thermal annealing process on the electrical and optical properties of ZnO:Ga (GZO) films prepared by sol–gel method. Experimental data indicated that the preferential growth directions of ZnO crystallites were the (002) and (103) axes. This phenomenon implied that the nucleation and growth behaviors of ZnO crystallites were changed by the infrared heating procedure and monoethanolamine. Furthermore, since the deposited sol films were heated simultaneously, evenly, and rapidly, dopant material Ga got the opportunity to replace Zn instead of forming oxides embedded in grain boundary areas. Thus, carrier concentration of the GZO films can be considerably enhanced while the mobility of the GZO films was not apparently affected in our experiments. It was also found that the carrier concentration was not sensitive to Ga/Zn ratio even though higher Ga concentration led to lower mobility. The best sample with a resistivity of 2.20 × 10−3 Ω cm and a transmittance of over 80% in visible region was achieved with 1.0 at.% Ga.

Two novel limonoids, swiemahogins A (1) and B (2) isolated from the twigs and leaves of Swietenia mahogany, are the first examples of andirobin and phragmalin types of limonoids, of which the D-ring δ-lactone is demolished and a rare γ-lactone is fused to the C-ring at C-8 and C-14. Their structures were elucidated by extensive spectroscopic means, and that of 1 was confirmed by single-crystal X-ray diffraction.

Rate constants directly measured by GC/MS-analyzed method for reduction of haloadamantanes by Sml 2 in presence of HMPA and H 2 O were obtained. HMPA exhibits stronger catalytic effect than H 2 O does. The result of faster reaction rate of 1-bromoadamantane than that of 2-bromoadamantane can be used to confirm the formation of alkyl radical as the rate limiting step of this reduction.

In this work, the planar HKMG MOS devices are fabricated on (100) wafer with p-substrate. To improve the samples' interface roughness between the Si/Ge film and the interface layer, three different clean treatments are considered to fabricate the MOS devices. Among processes, the experiment indicates that HF and water rinse can present hydrogen termination to bond silicon as a good passivation. The measured C-V curves and HRTEM of the fabricated samples show the interface roughness is improved significantly. The extracted shift of flat band voltage (ΔVfb) and density of interface traps (Dit) have around 50% improvement.

In this study, we implement a device simulation-based multi-objective evolutionary algorithm (MOEA) for the optimal design of silicon solar cells. The short-circuited current, the open-circuited voltage, and the conversion efficiency are calculated and used to evaluate the fitness score and access the evolutionary quality of designing parameters via the implemented non-dominating sorting genetic algorithm in the unified optimization framework. Designing parameters, the material and structural parameters are simultaneously optimized for the explored solar cells. Our device simulation-based MOEA methodology is useful, compared with the conventional genetic algorithm, in the solar cell design optimization.

Management of process variation and random fluctuation is one of severe challenges in scaling down silicon-based devices continuously according to Moore's law. Emerging fluctuation sources [1‒3] consists of the most critical random dopant fluctuation (RDF) which degrade device characteristic significantly. Unfortunately, recent studies on RDDs were reported for SOI FinFETs [1,5,8]. In this work, we for the first time statistically study characteristic fluctuation of 16-nm-gate high-к/metal gate (HKMG) bulk FinFETs with different aspect ratios (AR = 1 and 2; AR = H fin /W fin ) by random-discrete-dopants (RDDs) inside silicon fin channel, based upon our recent simulation studies [1–2,4–7]. Randomly generated devices with three-dimensional (3D) RDDs inside device channel is incorporated into quantum-mechanically corrected 3D device simulation. We compared the DC characteristics for planar and bulk FinFET devices. For the N-type bulk FinFET with AR = 2, it has higher I on and lower I off , further more the fluctuation of I on and I off are both smaller than the results of planar one, and the fluctuation of threshold voltage (σV th ) is 46.2 mV for the simulated N-MOSFETs which is significantly reduced to 22.9 mV for the bulk FinFET with AR = 2. We also discuss drain induced barrier lowering (DIBL) and subthreshold swing (S.S) for all devices, and the AR2 FinFET possesses the best performance no matter for the DIBL or S.S effects. There is 68.7% improvement on DIBL and 30.1% improvement on S.S from the planar [1,5,7–8] to AR2 FinFET. The findings of this study indicate that there is a relation between DIBL and RDD's position in which they are near or away from the silicon fin channel surface. It explains the different fluctuation magnitudes of the degraded DIBL effect on devices with the same number of RDDs.

In this work, we for the first time classify dopants that exist near the source/drain side or the upper/lower side of silicon fin and explore the impact of random dopants' (RDs) position on devices' DC characteristic. The effects of random dopant fluctuation (RDF) on the performance of 16–nm–gate HKMG bulk FinFET are studied by using experimentally validated three–dimensional RDF device simulation. The dopants near the source side or the upper fin would induce large barrier for electrons, so the threshold voltage (Vth) will be increased in n–type HKMG bulk FinFET devices which have more dopants on the source side or the upper fin. In addition, the upper–fin's dopants are discovered to have larger influence on the profile of energy band. Moreover, the issue about Vth's fluctuation on both the planar MOSFET and the bulk FinFETs with different aspect ratios (AR) is studied. The higher–AR HKMG bulk FinFET devices have relatively smaller Vth's variation induced by RDF.

In this paper, we, for the first time, study the metal gate's work-function-fluctuation-induced variability in the 16-nm-gate bulk and silicon on insulator (SOI) fin-type field effect transistor (FinFET) devices using an experimentally calibrated 3D device simulation. According to metal's property, random nanosized grains of titanium nitride (TiN) gate are statistically positioned in the gate region to examine the associated electrostatic potential and carrier transportation characteristics, concurrently capturing fluctuations resulting from nanosized grain's random number, position and size effects. The newly advanced methodology of localised work function fluctuation simulation enables us to estimate characteristic fluctuations and to examine the nanosized grain's random effects for the 16-nm-gate bulk and SOI FinFETs with TiN/HfO2 gate stacks with respect to the aspect ratio (AR = fin height/fin width) of two. The results of this study show that the DC characteristic fluctuation of FinFET devices strongly depends on the high and low work functions of localised nanosized metal grains. The threshold voltage (Vth) varies with the number of grain sizes and the Vth's fluctuation (σVth) is suppressed as the grain size is minimised. σVth of SOI FinFET (about 9.7 mV) is about 1.5 times smaller than that with bulk FinFET (about 14.6 mV). Furthermore, σVth of SOI FinFET with minimal metal grain's size of 2 × 2 nm2 can be reduced about 23%, compared with the result of bulk one.