Shadowed versus Etched Superconductor-Semiconductor Junctions in Al/InAs Nanowires.

Hybrid semiconductor-superconductor nanowires have emerged as a cornerstone in modern quantum devices. Integrating such nanowires into hybrid devices typically requires extensive postgrowth processing which may affect device performance unfavorably. Here, we present a technique for in situ shadowing superconductors on nanowires and compare the structural and electronic properties of Al junctions formed by shadowing versus etching. Based on transmission electron microscopy, we find that typical etching procedures lead to atomic-scale surface roughening. This surface perturbation may cause a reduction of the electron mobility as demonstrated in transport measurements. Further, we display advanced shadowing geometries aiding in the pursuit of bringing fabrication of hybrid devices in situ. Finally, we give examples of shadowed junctions exploited in various device geometries that exhibit high-quality quantum transport signatures.

Attention, response inhibition, impulsivity, and decision-making within luteal phase in women with premenstrual dysphoric disorder.

Cognitive impairment is a key feature of depressive disorder. Various forms of cognitive function have yet to be investigated in women with premenstrual dysphoric disorder (PMDD) during early luteal (EL) and late luteal (LL) phases. Therefore, we evaluated response inhibition and attention in PMDD in these two phases. We also examined the associations between cognitive functions, impulsivity, decision-making style, and irritability. There is a total of 63 female participants with PMDD and 53 controls, as determined through psychiatric diagnostic interviewing and a weekly symptoms checklist. The participants completed a Go/No-go task, Dickman's impulsivity inventory, Preference for Intuition and Deliberation scale, and the Buss-Durkee Hostility Inventory: Chinese Version-Short Form at the EL and LL phases. The women with PMDD had poorer attention in the Go trials at the LL phase and poorer response inhibition in the No-go trials at the EL and LL phases. Repeated measures analysis of variance revealed an LL exacerbation of deficit in attention among PMDD group. In addition, impulsivity negatively correlated with response inhibition at the LL phase. Preference for deliberation correlated with attention at the LL phase. Women with PMDD experienced LL declined attention and impaired response inhibition across the luteal phase. Response inhibition is linked to impulsivity. The deficit in attention links preference for deliberation among women with PMDD. These results reveal the different courses in different domains of cognitive impairment in PMDD. Further studies are required to elucidate the mechanism underlying cognitive dysfunction in PMDD.

Specific activation of pro-Infliximab enhances selectivity and safety of rheumatoid arthritis therapy.

During rheumatoid arthritis (RA) treatment, long-term injection of antitumor necrosis factor α antibodies (anti-TNFα Abs) may induce on-target toxicities, including severe infections (tuberculosis [TB] or septic arthritis) and malignancy. Here, we used an immunoglobulin G1 (IgG1) hinge as an Ab lock to cover the TNFα-binding site of Infliximab by linking it with matrix metalloproteinase (MMP) -2/9 substrate to generate pro-Infliximab that can be specifically activated in the RA region to enhance the selectivity and safety of treatment. The Ab lock significantly inhibits the TNFα binding and reduces the anti-idiotypic (anti-Id) Ab binding to pro-Infliximab by 395-fold, 108-fold compared with Infliximab, respectively, and MMP-2/9 can completely restore the TNFα neutralizing ability of pro-Infliximab to block TNFα downstream signaling. Pro-Infliximab was only selectively activated in the disease site (mouse paws) and presented similar pharmacokinetics (PKs) and bio-distribution to Infliximab. Furthermore, pro-Infliximab not only provided equivalent therapeutic efficacy to Infliximab but also maintained mouse immunity against Listeria infection in the RA mouse model, leading to a significantly higher survival rate (71%) than that of the Infliximab treatment group (0%). The high-selectivity pro-Infliximab maintains host immunity and keeps the original therapeutic efficiency, providing a novel strategy for RA therapy.

Inhibition of gut microbial ß-glucuronidase effectively prevents carcinogen-induced microbial dysbiosis and intestinal tumorigenesis.

The bidirectional interaction between carcinogens and gut microbiota that contributes to colorectal cancer is complicated. Reactivation of carcinogen metabolites by microbial ß-glucuronidase (ßG) in the gut potentially plays an important role in colorectal carcinogenesis. We assessed the chemoprotective effects and associated changes in gut microbiota induced by pre-administration of bacterial-specific ßG inhibitor TCH-3511 in carcinogen azoxymethane (AOM)-treated APCMin/+ mice. AOM induced intestinal ßG activity, which was reflected in increases in the incidence, formation, and number of tumors in the intestine. Notably, inhibition of gut microbial ßG by TCH-3511 significantly reduced AOM-induced intestinal ßG activity, decreased the number of polyps in both the small and large intestine to a frequency that was similar in mice without AOM exposure. AOM also led to lower diversity and altered composition in the gut microbiota with a significant increase in mucin-degrading Akkermansia genus. Conversely, mice treated with TCH-3511 and AOM exhibited a more similar gut microbiota structure as mice without AOM administration. Importantly, TCH-3511 treatment significant decreased Akkermansia genus and produced a concomitant increase in short-chain fatty acid butyrate-producing gut commensal microbes Lachnoospiraceae NK4A136 group genus in AOM-treated mice. Taken together, our results reveal a key role of gut microbial ßG in promoting AOM-induced gut microbial dysbiosis and intestinal tumorigenesis, indicating the chemoprotective benefit of gut microbial ßG inhibition against carcinogens via maintaining the gut microbiota balance and preventing cancer-associated gut microbial dysbiosis. Thus, the bacterial-specific ßG inhibitor TCH-3511 is a potential chemoprevention agent for colorectal cancer.

A universal in silico V(D)J recombination strategy for developing humanized monoclonal antibodies.

BACKGROUND: Humanization of mouse monoclonal antibodies (mAbs) is crucial for reducing their immunogenicity in humans. However, humanized mAbs often lose their binding affinities. Therefore, an in silico humanization method that can prevent the loss of the binding affinity of mAbs is needed. METHODS: We developed an in silico V(D)J recombination platform in which we used V(D)J human germline gene sequences to design five humanized candidates of anti-tumor necrosis factor (TNF)-α mAbs (C1-C5) by using different human germline templates. The candidates were subjected to molecular dynamics simulation. In addition, the structural similarities of their complementarity-determining regions (CDRs) to those of original mouse mAbs were estimated to derive the weighted interatomic root mean squared deviation (wRMSDi) value. Subsequently, the correlation of the derived wRMSDi value with the half maximal effective concentration (EC50) and the binding affinity (KD) of the humanized anti-TNF-α candidates was examined. To confirm whether our in silico estimation method can be used for other humanized mAbs, we tested our method using the anti-epidermal growth factor receptor (EGFR) a4.6.1, anti-glypican-3 (GPC3) YP9.1 and anti-α4ß1 integrin HP1/2L mAbs. RESULTS: The R2 value for the correlation between the wRMSDi and log(EC50) of the recombinant Remicade and those of the humanized anti-TNF-α candidates was 0.901, and the R2 value for the correlation between wRMSDi and log(KD) was 0.9921. The results indicated that our in silico V(D)J recombination platform could predict the binding affinity of humanized candidates and successfully identify the high-affinity humanized anti-TNF-α antibody (Ab) C1 with a binding affinity similar to that of the parental chimeric mAb (5.13 × 10-10). For the anti-EGFR a4.6.1, anti-GPC3 YP9.1, and anti-α4ß1 integrin HP1/2L mAbs, the wRMSDi and log(EC50) exhibited strong correlations (R2 = 0.9908, 0.9999, and 0.8907, respectively). CONCLUSIONS: Our in silico V(D)J recombination platform can facilitate the development of humanized mAbs with low immunogenicity and high binding affinities. This platform can directly transform numerous mAbs with therapeutic potential to humanized or even human therapeutic Abs for clinical use.

Signaling pathway of globo-series glycosphingolipids and ß1,3-galactosyltransferase V (ß3GalT5) in breast cancer.

The globo-series glycosphingolipids (GSLs) SSEA3, SSEA4, and Globo-H specifically expressed on cancer cells are found to correlate with tumor progression and metastasis, but the functional roles of these GSLs and the key enzyme ß1,3-galactosyltransferase V (ß3GalT5) that converts Gb4 to SSEA3 remain largely unclear. Here we show that the expression of ß3GalT5 significantly correlates with tumor progression and poor survival in patients, and the globo-series GSLs in breast cancer cells form a complex in membrane lipid raft with caveolin-1 (CAV1) and focal adhesion kinase (FAK) which then interact with AKT and receptor-interacting protein kinase (RIP), respectively. Knockdown of ß3GalT5 disrupts the complex and induces apoptosis through dissociation of RIP from the complex to interact with the Fas death domain (FADD) and trigger the Fas-dependent pathway. This finding provides a link between SSEA3/SSEA4/Globo-H and the FAK/CAV1/AKT/RIP complex in tumor progression and apoptosis and suggests a direction for the treatment of breast cancer, as demonstrated by the combined use of antibodies against Globo-H and SSEA4.

Psychological distress among immigrant women who divorced: Resilience as a mediator.

PURPOSE: The purpose of this study was to investigate relationships among the demands of immigration, resilience, and psychological distress in divorced immigrant women, and determine the mediating effects of resilience on the relationship between demands of immigration and psychological distress. DESIGN: The cross-sectional study included 117 women who had immigrated and married Taiwanese men but later got divorced. METHODS: The Chinese health questionnaire-12 scale, the resilience scale-Chinese version, and the demands of immigration (DI) scale were used to measure in this study. A multiple regression and Sobel test were used to examine whether resilience mediated the relationship between demands of immigration and psychological distress. FINDINGS: In this study, 47% of the divorced immigrant women were experiencing psychological distress, and 25.6% exhibited high levels of demands of immigration. Women with psychological distress had higher demand scores (t = 2.592, p = 0.011) and lower resilience scores (t = -3.965, p < 0.001) compared to women without psychological distress. The demands of immigration negatively predicted resilience (t = -3.050, p = 0.003). Finally, resilience mediated the association of demands of immigration with psychological distress (z = 2.497, p = 0.0125). CONCLUSIONS: Relationships among the demands of immigration, resilience, and psychological distress in divorced immigrant women were demonstrated in this study. Resilience played an important role in the relationship between demands of immigration and psychological distress. CLINICAL RELEVANCE: Tailored programs that foster resilience to reduce risks of demands of immigration and psychological distress in this vulnerable population should be developed.

Arabidopsis JMJ17 promotes cotyledon greening during de-etiolation by repressing genes involved in tetrapyrrole biosynthesis in etiolated seedlings.

Arabidopsis histone H3 lysine 4 (H3K4) demethylases play crucial roles in several developmental processes, but their involvement in seedling establishment remain unexplored. Here, we show that Arabidopsis JUMONJI DOMAIN-CONTAINING PROTEIN17 (JMJ17), an H3K4me3 demethylase, is involved in cotyledon greening during seedling establishment. Dark-grown seedlings of jmj17 accumulated a high concentration of protochlorophyllide, an intermediate metabolite in the tetrapyrrole biosynthesis (TPB) pathway that generates chlorophyll (Chl) during photomorphogenesis. Upon light irradiation, jmj17 mutants displayed decreased cotyledon greening and reduced Chl level compared with the wild-type; overexpression of JMJ17 completely rescued the jmj17-5 phenotype. Transcriptomics analysis uncovered that several genes encoding key enzymes involved in TPB were upregulated in etiolated jmj17 seedlings. Consistently, chromatin immunoprecipitation-quantitative PCR revealed elevated H3K4me3 level at the promoters of target genes. Chromatin association of JMJ17 was diminished upon light exposure. Furthermore, JMJ17 interacted with PHYTOCHROME INTERACTING FACTOR1 in the yeast two-hybrid assay. JMJ17 binds directly to gene promoters to demethylate H3K4me3 to suppress PROTOCHLOROPHYLLIDE OXIDOREDUCTASE C expression and TPB in the dark. Light results in de-repression of gene expression to modulate seedling greening during de-etiolation. Our study reveals a new role for histone demethylase JMJ17 in controlling cotyledon greening in etiolated seedlings during the dark-to-light transition.

Hot-Carrier Extraction in Nanowire-Nanoantenna Photovoltaic Devices.

Nanowires bring new possibilities to the field of hot-carrier photovoltaics by providing flexibility in combining materials for band engineering and using nanophotonic effects to control light absorption. Previously, an open-circuit voltage beyond the Shockley-Queisser limit was demonstrated in hot-carrier devices based on InAs-InP-InAs nanowire heterostructures. However, in these first experiments, the location of light absorption, and therefore the precise mechanism of hot-carrier extraction, was uncontrolled. In this Letter, we combine plasmonic nanoantennas with InAs-InP-InAs nanowire devices to enhance light absorption within a subwavelength region near an InP energy barrier that serves as an energy filter. From photon-energy- and irradiance-dependent photocurrent and photovoltage measurements, we find that photocurrent generation is dominated by internal photoemission of nonthermalized hot electrons when the photoexcited electron energy is above the barrier and by photothermionic emission when the energy is below the barrier. We estimate that an internal quantum efficiency up to 0.5-1.2% is achieved. Insights from this study provide guidelines to improve internal quantum efficiencies based on nanowire heterostructures.

Humanized bispecific antibody (mPEG × HER2) rapidly confers PEGylated nanoparticles tumor specificity for multimodality imaging in breast cancer.

BACKGROUND: Developing a universal strategy to improve the specificity and sensitivity of PEGylated nanoaparticles (PEG-NPs) for assisting in the diagnosis of tumors is important in multimodality imaging. Here, we developed the anti-methoxypolyethylene glycol (mPEG) bispecific antibody (BsAb; mPEG × HER2), which has dual specificity for mPEG and human epidermal growth factor receptor 2 (HER2), with a diverse array of PEG-NPs to confer nanoparticles with HER2 specificity and stronger intensity. RESULT: We used a one-step formulation to rapidly modify the nanoprobes with mPEG × HER2 and optimized the modified ratio of BsAbs on several PEG-NPs (Lipo-DiR, SPIO, Qdot and AuNP). The αHER2/PEG-NPs could specifically target MCF7/HER2 cells (HER2++) but not MCF7/neo1 cells (HER2+/-). The αHER2/Lipo-DiR and αHER2/SPIO could enhance the sensitivity of untargeted PEG-NPs on MCF7/HER2 (HER2++). In in vivo imaging, αHER2/Lipo-DiR and αHER2/SPIO increased the specific targeting and enhanced PEG-NPs accumulation at 175% and 187% on 24 h, respectively, in HER2-overexpressing tumors. CONCLUSION: mPEG × HER2, therefore, provided a simple one-step formulation to confer HER2-specific targeting and enhanced sensitivity and contrast intensity on HER2 positive tumors for multimodality imaging.

Pharmacological inhibition of bacterial ß-glucuronidase prevents irinotecan-induced diarrhea without impairing its antitumor efficacy in vivo.

Irinotecan (CPT-11), a first-line chemotherapy for advanced colorectal cancer, causes serious diarrhea in patients receiving treatment. The underlying mechanism has been shown that the active metabolite of CPT-11, SN-38, is metabolized to the inactive metabolite SN-38 glucuronide (SN-38 G) during hepatic glucuronidation, and subsequently is exported into the intestine, where SN-38 G is hydrolyzed by bacterial ß-glucuronidase (ßG) to be SN-38, thus leading to intestinal toxicity. Thus, inhibition of the intestinal bacterial ßG activity is expected to prevent CPT-11-induced diarrhea. However, the effects of such inhibition on serum pharmacokinetics of SN-38, the key determinant of CPT-11 treatment, are uncertain. Here, we determined the effects of a potent E. coli ßG (eßG)-specific inhibitor pyrazolo[4,3-c]quinoline derivative (TCH-3562) for the potential use in preventing CPT-11-induced diarrhea. TCH-3562 exhibited efficacious inhibitory potency of endogenous ßG activity in two anaerobes, Eubacteriumsp. and Peptostreptococcus anaerobius. Oral administration of TCH-3562 also effectively reduced the bacterial ßG activity in mice intestine. Moreover, pharmacokinetic analysis of TCH-3562 revealed a relatively low amount of TCH-3562 was detected in the plasma whereas the majority of TCH-3562 was found in the feces. Importantly, co-treatment of CPT-11 and TCH-3562 did not decrease active SN-38 level in mice plasma. Finally, we established that TCH-3562 as an adjuvant treatment showed protective effects on CPT-11-induced diarrhea and had no negative effects on the therapeutic efficacy of CPT-11 in tumor-bearing mice. Therefore, inhibition of the intestinal bacterial ßG activity by the specific inhibitor, TCH-3562, is promising to prevent CPT-11-induced diarrhea while maintaining its anti-tumor efficacy that may have clinical potentials for the treatment with CPT-11.

Effect of a community-based participatory health literacy program on health behaviors and health empowerment among community-dwelling older adults: A quasi-experimental study.

This study evaluated the effect of a community-based participatory health literacy program aimed at improving the health behaviors and health empowerment for older adults. A two-group pretest and posttest quasi-experimental design with surveys conducted at baseline (T1), immediately after the intervention (T2), and 6 months after the intervention (T3). The intervention group (n = 94) attended a 12-week health literacy program; while the comparison group (n = 78) did not. The results demonstrated that intervention group had significantly better health behavior practices for weight control (OR = 3.71, 95% CI = 1.59-8.64), regular exercise (OR = 15.26, 95% CI = 1.92-121.13), and health information navigation (OR = 2.61, 95% CI = 1.16-5.84). Health empowerment was significantly higher in the intervention group than the comparison group (p < 0.01).This study suggests that integrating community-based participatory design is effective in improving some health behaviors and health empowerment in older adults over a short period.

Thermoelectric Power Factor Limit of a 1D Nanowire.

In the past decade, there has been significant interest in the potentially advantageous thermoelectric properties of one-dimensional (1D) nanowires, but it has been challenging to find high thermoelectric power factors based on 1D effects in practice. Here we point out that there is an upper limit to the thermoelectric power factor of nonballistic 1D nanowires, as a consequence of the recently established quantum bound of thermoelectric power output. We experimentally test this limit in quasiballistic InAs nanowires by extracting the maximum power factor of the first 1D subband through I-V characterization, finding that the measured maximum power factors conform to the theoretical limit. The established limit allows the prediction of the achievable power factor of a specific nanowire material system with 1D electronic transport based on the nanowire dimension and mean free path. The power factor of state-of-the-art semiconductor nanowires with small cross section and high crystal quality can be expected to be highly competitive (on the order of mW/m K^{2}) at low temperatures. However, they have no clear advantage over bulk materials at, or above, room temperature.

Premenstrual appetite and emotional responses to foods among women with premenstrual dysphoric disorder.

The aim of the study was to evaluate changes in late-luteal appetite for highly sweet (HS) and highly salty and fatty (HSF) foods in women with premenstrual dysphoric disorder (PMDD). After initial assessment in a psychiatric interview, the premenstrual symptoms screening tool (PSST) was used to identify women with moderate-to-severe premenstrual symptoms. Sixty-seven women with PMDD and 74 healthy controls were evaluated in the early-follicular and late-luteal (pre-menstrual) phases of the menstrual cycle. Because the PSST is designed to assess symptoms only in the late-luteal phase, an 11-point Likert scale was used to rate PMDD symptoms once a week in the evaluation mentioned previously and the following two menstrual cycles. Participants were shown pictures of 15 highly sweet (HS) and 15 highly salty and fatty (HSF) foods, desire to eat each food was rated on an eleven-point Likert scale (0, "none at all"; 10, "extreme desire"), and sweet-food craving was rated using the food craving-state questionnaire. Emotional responses to the foods were measured with a four-point Likert scale we previously validated. Depression, irritability, and impulsivity were measured with standard psychiatric instruments. Women with PMDD, but not control women, had late-luteal phase elevations in desire to eat HS food, sweet-food craving and emotional responses to HS foods. Desire to eat for HSF foods did not differ significantly across the menstrual cycle between groups. There were significant correlations between emotional responses to and desire to eat HS foods. Moreover, late-luteal phase irritability and impulsivity scores were associated with desire to eat HS foods. These data suggest that targeted assessment of increased late-luteal appetites for HS foods may facilitate clinical interventions in women with PMDD.

Parallel-Coupled Quantum Dots in InAs Nanowires.

We use crystal-phase tuning during epitaxial growth of InAs nanowires to create quantum dots with very strong confinement. A set of gate electrodes are used to reproducibly split the quantum dots into even smaller pairs for which we can control the populations down to the last electron. The double quantum dots, which are parallel-coupled to source and drain, show clear and stable odd-even level pairing due to spin degeneracy and the strong confinement. The combination of hard-wall barriers to source and drain, shallow interdot tunnel barriers, and very high single-particle excitation energies allow an order of magnitude tuning of the strength for the first intramolecular bond. We show examples for nanowires with different facet orientations, and suggest possible mechanisms behind the reproducible double-dot formation.

Conduction Band Offset and Polarization Effects in InAs Nanowire Polytype Junctions.

Although zinc-blende (ZB) and wurtzite (WZ) structures differ only in the atomic stacking sequence, mixing of crystal phases can strongly affect the electronic properties, a problem particularly common to bottom up-grown nanostructures. A lack of understanding of the nature of electronic transport at crystal phase junctions thus severely limits our ability to develop functional nanowire devices. In this work we investigated electron transport in InAs nanowires with designed mixing of crystal structures, ZB/WZ/ZB, by temperature-dependent electrical measurements. The WZ inclusion gives rise to an energy barrier in the conduction band. Interpreting the experimental result in terms of thermionic emission and using a drift-diffusion model, we extracted values for the WZ/ZB band offset, 135 ± 10 meV, and interface sheet polarization charge density on the order of 10-3 C/m2. The extracted polarization charge density is 1-2 orders of magnitude smaller than previous experimental results, but in good agreement with first principle calculation of spontaneous polarization in WZ InAs. When the WZ length is reduced below 20 nm, an effective barrier lowering is observed, indicating the increasing importance of tunneling transport. Finally, we found that band-bending at ZB/WZ junctions can lead to bound electron states within an enclosed WZ segment of sufficient length, evidenced by our observation of Coulomb blockade at low temperature. These findings provide critical input for modeling and designing the electronic properties of novel functional devices, such as nanowire transistors, where crystal polytypes are commonly found.

Bipolar Photothermoelectric Effect Across Energy Filters in Single Nanowires.

The photothermoelectric (PTE) effect uses nonuniform absorption of light to produce a voltage via the Seebeck effect and is of interest for optical sensing and solar-to-electric energy conversion. However, the utility of PTE devices reported to date has been limited by the need to use a tightly focused laser spot to achieve the required, nonuniform illumination and by their dependence upon the Seebeck coefficients of the constituent materials, which exhibit limited tunability and, generally, low values. Here, we use InAs/InP heterostructure nanowires to overcome these limitations: first, we use naturally occurring absorption "hot spots" at wave mode maxima within the nanowire to achieve sharp boundaries between heated and unheated subwavelength regions of high and low absorption, allowing us to use global illumination; second, we employ carrier energy-filtering heterostructures to achieve a high Seebeck coefficient that is tunable by heterostructure design. Using these methods, we demonstrate PTE voltages of hundreds of millivolts at room temperature from a globally illuminated nanowire device. Furthermore, we find PTE currents and voltages that change polarity as a function of the wavelength of illumination due to spatial shifting of subwavelength absorption hot spots. These results indicate the feasibility of designing new types of PTE-based photodetectors, photothermoelectrics, and hot-carrier solar cells using nanowires.

Enhancement Effect of a Variable Topology of a Membrane-Tethered Anti-Poly(ethylene glycol) Antibody on the Sensitivity for Quantifying PEG and PEGylated Molecules.

Sensitive quantification of the pharmacokinetics of poly(ethylene glycol) (PEG) and PEGylated molecules is critical for PEGylated drug development. Here, we developed a sensitive sandwich enzyme-linked immunosorbent assay (ELISA) for PEG by tethering an anti-PEG antibody (AGP3) via tethers with different dimensions on the surface of 293T cells (293T/S-αPEG, short-type cells; 293T/L-αPEG, long-type cells; 293T/SL-αPEG, hybrid-type cells) to improve the binding capacity and detection limit for free PEG and PEGylated molecules. The binding capacity of hybrid-type cells for PEG-like molecules (CH3-PEG5K-FITC (FITC = fluorescein isothiocyanate) and eight-arm PEG20K-FITC) was at least 10-80-fold greater than that of 293T cells expressing anti-PEG antibodies with uniform tether lengths. The detection limit of free PEG (OH-PEG3K-NH2 and CH3-PEG5K-NH2) and PEG-like molecule (CH3-PEG5K-FITC, CH3-PEG5K-SHPP, and CH3-PEG5K-NIR797) was14-137 ng mL-1 in the hybrid-type cell-based sandwich ELISA. 293T/SL-αPEG cells also had significantly higher sensitivity for quantification of a PEGylated protein (PegIntron) and multiarm PEG macromolecules (eight-arm PEG20K-NH2 and eight-arm PEG40K-NH2) at 3.2, 16, and 16 ng mL-1, respectively. Additionally, the overall binding capacity of 293T/SL-αPEG cells for PEGylated macromolecules was higher than that of 293T/S-αPEG or 293T/L-αPEG cells. Anchoring anti-PEG antibodies on cells via variable-length tethers for cell-based sandwich ELISA, therefore, provides a sensitive, high-capacity method for quantifying free PEG and PEGylated molecules.

Single-nanowire, low-bandgap hot carrier solar cells with tunable open-circuit voltage.

Compared to traditional pn-junction photovoltaics, hot carrier solar cells offer potentially higher efficiency by extracting work from the kinetic energy of photogenerated 'hot carriers' before they cool to the lattice temperature. Hot carrier solar cells have been demonstrated in high-bandgap ferroelectric insulators and GaAs/AlGaAs heterostructures, but so far not in low-bandgap materials, where the potential efficiency gain is highest. Recently, a high open-circuit voltage was demonstrated in an illuminated wurtzite InAs nanowire with a low bandgap of 0.39 eV, and was interpreted in terms of a photothermoelectric effect. Here, we point out that this device is a hot carrier solar cell and discuss its performance in those terms. In the demonstrated devices, InP heterostructures are used as energy filters in order to thermoelectrically harvest the energy of hot electrons photogenerated in InAs absorber segments. The obtained photovoltage depends on the heterostructure design of the energy filter and is therefore tunable. By using a high-resistance, thermionic barrier, an open-circuit voltage is obtained that is in excess of the Shockley-Queisser limit. These results provide generalizable insight into how to realize high voltage hot carrier solar cells in low-bandgap materials, and therefore are a step towards the demonstration of higher efficiency hot carrier solar cells.

Optimization of an Anti-poly(ethylene glycol) (anti-PEG) Cell-Based Capture System To Quantify PEG and PEGylated Molecules.

Sensitive determination of the pharmacokinetics of PEGylated molecules can accelerate the process of drug development. Here, we combined different anti-PEG Fab expressing 293T cells as capture cells (293T/3.3, 293T/6.3, and 293T/15-2b cells) with four detective anti-PEG antibodies (3.3, 6.3, 7A4, or 15-2b) to optimize an anti-PEG cell-based sandwich ELISA. Then, we quantified free PEG (mPEG2K-NH2 and mPEG5K-NH2) or PEG-conjugated small molecules (mPEG5K-biotin and mPEG5K-NIR797), proteins (PegIntron and Pegasys), and nanoparticles (Liposomal-Doxorubicin and quantum-dots). The combination of 293T/15-2b cells and the 7A4 detection antibody was best sensitivity for free PEG, PEG-like molecules, and PEGylated proteins with detection at ng mL-1 levels. On the other hand, 293T/3.3 cells combined with the 15-2b antibody had the highest sensitivity for quantifying Lipo-Dox at 2 ng mL-1. All three types of anti-PEG cells combined with the 15-2b antibody had high sensitivity for quantum dot quantification down to 7 pM. These results suggest that the combination of 293T/15-2b cells and 7A4 detection antibody is the optimal pair for sensitive quantification of free PEG, PEG-like molecules, and PEGylated proteins, whereas the 293T/3.3 cells combined with 15-2b are more suitable for quantifying PEGylated nanoparticles. The optimized anti-PEG cell-based sandwich ELISA can provide a sensitive, precise, and convenient tool for the quantification of a range of PEGylated molecules.