Versatile Bottom-Up Synthesis of Tethered Bilayer Lipid Membranes on Nanoelectronic Biosensor Devices

Interfacing nanoelectronic devices with cell membranes can enable multiplexed detection of fundamental biological processes (such as signal transduction, electrophysiology, and import/export control) even down to the single ion channel level, which can lead to a variety of applications in pharmacology and clinical diagnosis. Therefore, it is necessary to understand and control the chemical and electrical interface between the device and the lipid bilayer membrane. Here, we develop a simple bottom-up approach to assemble tethered bilayer lipid membranes (tBLMs) on silicon wafers and glass slides, using a covalent tether attachment chemistry based on silane functionalization, followed by step-by-step stacking of two other functional molecular building blocks (oligo-poly­(ethylene glycol) (PEG) and lipid). A standard vesicle fusion process was used to complete the bilayer formation. The monolayer synthetic scheme includes three well-established chemical reactions: self-assembly, epoxy-amine reaction, and EDC/NHS cross-linking reaction. All three reactions are facile and simple and can be easily implemented in many research labs, on the basis of common, commercially available precursors using mild reaction conditions. The oligo-PEG acts as the hydrophilic spacer, a key role in the formation of a homogeneous bilayer membrane. To explore the broad applicability of this approach, we have further demonstrated the formation of tBLMs on three common classes of (nano)­electronic biosensor devices: indium-tin oxide-coated glass, silicon nanoribbon devices, and high-density single-walled carbon nanotubes (SWNT) networks on glass. More importantly, we incorporated alemethicin into tBLMs and realized the real-time recording of single ion channel activity with high sensitivity and high temporal resolution using the tBLMs/SWNT network transistor hybrid platform. This approach can provide a covalently bonded lipid coating on the oxide layer of nanoelectronic devices, which will enable a variety of applications in the emerging field of nanoelectronic interfaces to electrophysiology

General Rules for Selective Growth of Enriched Semiconducting Single Walled Carbon Nanotubes with Water Vapor as in Situ Etchant

The presence of metallic nanotubes in as-grown single walled carbon nanotubes (SWNTs) is the major bottleneck for their applications in field-effect transistors. Herein, we present a method to synthesize enriched, semiconducting nanotube arrays on quartz substrate. It was discovered that introducing appropriate amounts of water could effectively remove the metallic nanotubes and significantly enhance the density of SWNT arrays. More importantly, we proposed and confirmed that the high growth selectivity originates from the etching effect of water and the difference in the chemical reactivities of metallic and semiconducting nanotubes. Three important rules were summarized for achieving a high selectivity in growing semiconducting nanotubes by systematically investigating the relationship among water concentration, carbon feeding rate, and the percentage of semiconducting nanotubes in the produced SWNT arrays. Furthermore, these three rules can be applied to the growth of random SWNT networks on silicon wafers

ALD TiO₂‑Coated Flower-like MoS₂ Nanosheets on Carbon Cloth as Sodium Ion Battery Anode with Enhanced Cycling Stability and Rate Capability

We report the fabrication of 3D flower-like MoS₂ nanosheets arrays on carbon cloth as a binder-free anode for sodium ion battery. Ultrathin and conformal TiO₂ layers are used to modify the surface of MoS₂ by atomic layer deposition. The electrochemical performance measurements demonstrate that the ALD TiO₂ layer can improve the cycling stability and rate capability of MoS₂. The MoS₂ nanosheets with 0.5-nm TiO₂ coating electrode show the highest initial discharge capacity of 1392 mA h g^–1 at 200 mA g^–1, which is increased by 53% compared with that of bare MoS₂. After 150 cycles, the capacity retention rate of the TiO₂-coated MoS₂ achieves 75.8% of its second cycle’s capacity at 200 mA h g^–1 in contrast to that of 59% of pure MoS₂. Furthermore, the mechanism behind the experimental results is revealed by ex situ scanning electron microscope (SEM), X-ray powder diffraction (XRD), and electrochemical impedance spectroscopy (EIS) characterizations, which confirms that the ultrathin TiO₂ modifications can prevent the structural degradation and the formation of SEI film of MoS₂ electrode

Aluminum Induces Distinct Changes in the Metabolism of Reactive Oxygen and Nitrogen Species in the Roots of Two Wheat Genotypes with Different Aluminum Resistance

Aluminum (Al) toxicity in acid soils is a primary factor limiting plant growth and crop yield worldwide. Considerable genotypic variation in resistance to Al toxicity has been observed in many crop species. In wheat (<i>Triticum aestivum</i> L.), Al phytotoxicity is a complex phenomenon involving multiple physiological mechanisms which are yet to be fully characterized. To elucidate the physiological and molecular basis of Al toxicity in wheat, we performed a detailed analysis of reactive oxygen species (ROS) and reactive nitrogen species (RNS) under Al stress in one Al-tolerant (Jian-864) and one Al-sensitive (Yang-5) genotype. We found Al induced a significant reduction in root growth with the magnitude of reduction always being greater in Yang-5 than in Jian-864. These reductions were accompanied by significant differences in changes in antioxidant enzymes and the nitric oxide (NO) metabolism in these two genotypes. In the Al-sensitive genotype Yang-5, Al induced a significant increase in ROS, NO, peroxynitrite (ONOO^–) and activities of NADPH oxidase, peroxidase, and S-nitrosoglutathione reductase (GSNOR). A concomitant reduction in glutathione and increase in S-nitrosoglutathione contents was also observed in Yang-5. In contrast, the Al-tolerant genotype Jian-864 showed lower levels of lipid peroxidation, ROS and RNS accumulation, which was likely achieved through the adjustment of its antioxidant defense system to maintain redox state of the cell. These results indicate that Al stress affected redox state and NO metabolism and caused nitro-oxidative stress in wheat. Our findings suggest that these molecules could be useful parameters for evaluating physiological conditions in wheat and other crop species under adverse conditions

Average Treatment Effect on Treated (ATT) for consistent condom use with all sex workers among male clients of female sex workers by usual pickup place of FSW, IBBA, 2009.

<p>AP: Andhra Pradesh; MH: Maharashtra; TN: Tamil Nadu</p

Table_1_The influence of cortisol co-secretion on clinical characteristics and postoperative outcomes in unilateral primary aldosteronism.docx

ContextThe prevalence of unilateral primary aldosteronism (UPA) with cortisol co-secretion varies geographically.ObjectiveTo investigate the prevalence and clinical characteristics of UPA with cortisol co-secretion in a Chinese population.DesignRetrospective cohort study.MethodsWe recruited 580 patients with UPA who underwent cosyntropin stimulation test (CST) after the 1-mg dexamethasone suppression test (DST) and retrospectively analyzed the clinical characteristics and postoperative outcomes of UPA with and without cortisol co-secretion.ResultsUPA with cortisol co-secretion (1 mg DST>1.8 ug/dL) was identified in 65 of 580 (11.2%) patients. These patients were characterized by older age, longer duration of hypertension, higher concentration of plasma aldosterone and midnight cortisol, lower adrenocorticotropic hormone (ACTH) and dehydroepiandrosterone sulfate (DHEAS), larger tumor diameter, and more history of diabetes mellitus. Cortisol and aldosterone levels were higher and DHEAS level was lower in UPA with cortisol co-secretion at 0–120 min after CST. Among 342 UPA patients with KCNJ5 gene sequencing and follow-up results, the complete clinical success rate was lower in UPA with cortisol co-secretion (33.3% vs. 56.4%, PConclusionsUPA with cortisol co-secretion is not uncommon in China, but the clinical features were distinctly different from those without co-secretion. Cortisol co-secretion is an independent risk factor for incomplete clinical success after surgery in UPA.</p

Controlling Nucleation Density While Simultaneously Promoting Edge Growth Using Oxygen-Assisted Fast Synthesis of Isolated Large-Domain Graphene

We report a two-step chemical vapor deposition growth method for rapid synthesis of isolated large-domain graphene. The key feature of the two-step growth method is to separate nucleation from growth, performing the nucleation in step one with a low carbon feedstock (methane) gas flow rate, and rapid growth in step two with a high flow rate. We find empirically that, even under the high flow rate conditions of step two, the nucleation density on the inside of the copper pocket used for growth is suppressed (preventing merging of domains into full films) until the graphene growing on the outside of the pocket merges into a full film, fully covering the outside. The mechanism for this suppression is believed to be related to oxygen-assisted passivation of nucleation sites, a decreased energetic barrier for edge-attachment growth, and diffusion of carbon through the copper bulk. These conditions enable us to finely tune the local carbon concentration on the inside surface for fast growth and minimum nucleation density and achieve a growth of 5 mm isolated graphene domains in under 5 h of total growth time, much faster than traditional one-step growth methods

Growth of High-Density-Aligned and Semiconducting-Enriched Single-Walled Carbon Nanotubes: Decoupling the Conflict between Density and Selectivity

Single-walled carbon nanotubes (SWNTs) are highly desired for future electronic applications due to the excellent electrical, mechanical, and thermal properties. However, the density and the selectivity in the growth of aligned semiconducting nanotubes do not coexist previously: when the selectivity is high, the density is low and <i>vice versa</i>. In the present work, we found that random carbon nanotubes (CNTs) in the catalyst area block the growth of aligned SWNTs along the lattice structure on the quartz surface, thus significantly reducing the density of nanotubes during growth. More interestingly, it was shown that the random CNTs can be selectively removed through appropriate treatments using water vapor as an <i>in situ</i> etchant while the aligned SWNTs survive even after long-time water vapor treatment. To obtain high-density semiconducting SWNT arrays, we designed an improved multiple-cycle growth method, which included the treatment of SWNTs with water vapor after each growth cycle without cooling the system. Using this method, we have successfully obtained dense semiconducting SWNTs (∼10 SWNTs/μm) over large areas and with high uniformity

Image_1_Efficacy and safety of adjuvant radiation therapy in localized adrenocortical carcinoma.pdf

ContextAdrenocortical carcinoma (ACC) is rare and have high rates of recurrence and mortality. The role of adjuvant radiation therapy (RT) in localized ACC was controversial.MethodsWe conducted a retrospective study in our center between 2015 and 2021 to evaluate the efficacy and safety of adjuvant RT in localized ACC. Overall survival (OS) and disease-free survival (DFS) were estimated using the Kaplan-Meier method. Cox proportional hazards regression models were used to estimate the independent risk factors. Adverse events associated with RT were documented according to the toxicity criteria of the radiation therapy oncology group (RTOG) and the common terminology criteria for adverse events (CTCAE v5.0).ResultsOf 105 patients with localized ACC, 46 (43.8%) received adjuvant RT after surgery. The median radiation dose was 45.0Gy (range:30.0-50.4) and median follow up time was 36.5 (IQR: 19.7-51.8) months. In comparison to the no adjuvant RT group, patients with adjuvant RT had better 3-year OS (87.9% vs 79.5%, P=0.039), especially for patients with ENSAT I/II stage (P=0.004). Adjuvant RT also improved the median DFS time from 16.5months (95%CI, 12.0-20.9) to 34.6months (95%CI, 16.1-53.0). Toxicity of RT was generally mild and moderate with six grade 3 events.ConclusionsPostoperative adjuvant RT significantly improved OS and DFS compared with the use of surgery alone in resected ACC patients. Although this retrospective study on RT in localized ACC indicates that RT is effective in ACC, its findings need to be prospectively confirmed.</p

Immunohistochemical staining of steroidogenic acute regulatory protein (StAR) in cortisol-producing ACAs with different genotypes.

<p>(A) Wild-type adenoma presenting with low StAR expression (H-score = 100); adenomas with mutations in (B) <i>PRKAR1A</i> (H-score = 200), (C) <i>GNAS</i> (H-score = 200), and (D) <i>PRKACA</i> presenting with high StAR expression (H-score = 200) (scale bar, 50 μm). <i>PRKAR1A</i>, protein kinase cAMP-dependent type I regulatory subunit alpha; <i>GNAS</i>, guanine nucleotide binding protein, alpha stimulating; <i>PRKACA</i>, protein kinase cyclic adenosine monophosphate (cAMP)-activated catalytic subunit alpha.</p