Prognostic Nutritional Index as a Prognostic Indicator for the Occurrence of Postoperative Complications in Patients with Esophageal Squamous Cell Carcinoma Following Neoadjuvant Immunochemotherapy.

Background & Aims: The objective of this study was to evaluate the prognostic nutritional index (PNI) as a predictor of short-term postoperative complications in esophageal squamous cell carcinoma patients undergoing neoadjuvant immunochemotherapy. Methods: Clinical data were collected from 77 patients undergoing radical esophageal cancer surgery after neoadjuvant immunochemotherapy at Tongji Hospital from January 2022 to January 2023. The receiver operating characteristic curve (ROC) was utilized to establish the optimal cut-off point for the PNI. Subsequently, patients were stratified into low and high PNI groups according to this cut-off point, and comparisons were made between the two groups in terms of clinical data and postoperative complications. Results: Out of the 77 patients included in the study, 31 were categorized in the low PNI group and 46 in the high PNI group, with a defined cutoff point of 47.38. Significant statistical variances were noted in the occurrence rates of general complications (P < 0.001), pulmonary infections (P < 0.001), and anastomotic fistula (P = 0.034) between the two groups. The low PNI group displayed elevated rates of these complications in comparison to the high PNI group. Conclusion: The research findings indicate that preoperative nutritional assessment using the PNI can effectively predict short-term postoperative complications in esophageal squamous cell carcinoma patients who have undergone neoadjuvant therapy. Furthermore, the results suggest that implementing nutritional interventions for patients with moderate-to-severe malnutrition, as indicated by preoperative PNI evaluation, may help reduce the incidence of postoperative complications.

Strategies for Controlling the Spatial Orientation of Single Molecules Tethered on DNA Origami Templates Physisorbed on Glass Substrates: Intercalation and Stretching.

Nanoarchitectural control of matter is crucial for next-generation technologies. DNA origami templates are harnessed to accurately position single molecules; however, direct single molecule evidence is lacking regarding how well DNA origami can control the orientation of such molecules in three-dimensional space, as well as the factors affecting control. Here, we present two strategies for controlling the polar (θ) and in-plane azimuthal (ϕ) angular orientations of cyanine Cy5 single molecules tethered on rationally-designed DNA origami templates that are physically adsorbed (physisorbed) on glass substrates. By using dipolar imaging to evaluate Cy5's orientation and super-resolution microscopy, the absolute spatial orientation of Cy5 is calculated relative to the DNA template. The sequence-dependent partial intercalation of Cy5 is discovered and supported theoretically using density functional theory and molecular dynamics simulations, and it is harnessed as our first strategy to achieve θ control for a full revolution with dispersion as small as ±4.5°. In our second strategy, ϕ control is achieved by mechanically stretching the Cy5 from its two tethers, being the dispersion ±10.3° for full stretching. These results can in principle be applied to any single molecule, expanding in this way the capabilities of DNA as a functional templating material for single-molecule orientation control. The experimental and modeling insights provided herein will help engineer similar self-assembling molecular systems based on polymers, such as RNA and proteins.

Correlative Super-Resolution and Atomic Force Microscopy of DNA Nanostructures and Characterization of Addressable Site Defects.

To bring real-world applications of DNA nanostructures to fruition, advanced microscopy techniques are needed to shed light on factors limiting the availability of addressable sites. Correlative microscopy, where two or more microscopies are combined to characterize the same sample, is an approach to overcome the limitations of individual techniques, yet it has seen limited use for DNA nanotechnology. We have developed an accessible strategy for high resolution, correlative DNA-based points accumulation for imaging in nanoscale topography (DNA-PAINT) super-resolution and atomic force microscopy (AFM) of DNA nanostructures, enabled by a simple and robust method to selectively bind DNA origami to cover glass. Using this technique, we examined addressable "docking" sites on DNA origami to distinguish between two defect scenarios-structurally incorporated but inactive docking sites, and unincorporated docking sites. We found that over 75% of defective docking sites were incorporated but inactive, suggesting unincorporated strands played a minor role in limiting the availability of addressable sites. We further explored the effects of strand purification, UV irradiation, and photooxidation on availability, providing insight on potential sources of defects and pathways toward improving the fidelity of DNA nanostructures.

An alternative approach to nucleic acid memory.

DNA is a compelling alternative to non-volatile information storage technologies due to its information density, stability, and energy efficiency. Previous studies have used artificially synthesized DNA to store data and automated next-generation sequencing to read it back. Here, we report digital Nucleic Acid Memory (dNAM) for applications that require a limited amount of data to have high information density, redundancy, and copy number. In dNAM, data is encoded by selecting combinations of single-stranded DNA with (1) or without (0) docking-site domains. When self-assembled with scaffold DNA, staple strands form DNA origami breadboards. Information encoded into the breadboards is read by monitoring the binding of fluorescent imager probes using DNA-PAINT super-resolution microscopy. To enhance data retention, a multi-layer error correction scheme that combines fountain and bi-level parity codes is used. As a prototype, fifteen origami encoded with 'Data is in our DNA!\n' are analyzed. Each origami encodes unique data-droplet, index, orientation, and error-correction information. The error-correction algorithms fully recover the message when individual docking sites, or entire origami, are missing. Unlike other approaches to DNA-based data storage, reading dNAM does not require sequencing. As such, it offers an additional path to explore the advantages and disadvantages of DNA as an emerging memory material.

[Effect of nanostructured lipid carriers (NLCs) in improving stability of essential oils and its application].

Essential oils are easy to cause oxidative damage, chemical transformation or polymerization, and have some intrinsic problems, such as instability, low water solubility and low bioavailability, which restrict their application in the fields of product development. Nanostructured lipid carriers(NLCs) can overcome some of the restrictions of other colloidal carriers, such as emulsions, liposomes, polymer nanoparticles and solid lipid nanoparticles. NLC is an efficient and stable delivery system for bioactive substances. With unique lipid properties(mixture of solid and liquid lipid), it can overcome the disadvantages of essential oils and protect them from adverse environments, thus improving the stability, bioavailability and safety of essential oils, and achieve sustained release and controlled release. In EOs-NLCs system, essential oils, as special liquid lipid with biological activities and medicinal properties, can fully play the role of medicine-adjuvant integration by changing the structural characteristics of mixed lipid. Based on the development of nanocarriers system, this paper introduces the composition and structural characteristics of EOs-NLCs, and clarifies how to improve the stability of essential oils based on the effects of NLCs on physical and chemical properties, physical stability and release of active components of essential oils. In addition, it also introduces the application of the system in the fields of pharmaceutical, food, cosmetics and skin care products. This review aims to provide some references for improving the stability of essential oils and their applications by using NLCs.

[Discussion on research thought of dry granulation of traditional Chinese medicine: research progress at home and abroad based on dry granulation technology].

Dry granulation technology is a great innovation in granulation technology,which saves many intermediate links and reduces many intermediate costs. It is closely related to the characteristics of materials,dry granulation equipment and process. Dry granulation technology is a systematic engineering science covering many technical fields. The process of dry granulation involves complex mathematical model mechanisms of temperature field,pressure field and velocity field,closely related to the characteristics of materials and drying equipment. However,due to the late start of research on dry granulation technology of traditional Chinese medicine,basic research is still weak. The research on dry granulation technology has achieved great results in the fields of food,chemical industry,agriculture and forestry,showing great reference significance. The advantage of dry granulation of traditional Chinese medicine is that it can be directly granulated by adding an appropriate amount of auxiliary materials in the extract powder of traditional Chinese medicine,without the need of wetting,mixing,drying and other processes. The process is simple and can effectively guarantee the quality of traditional Chinese medicine. The granules obtained by the dry granulation technique are important intermediates for preparing the solid preparations of traditional Chinese medicines,which would directly affect the subsequent molding process and the quality of the preparation products. Therefore,based on the characteristics of dry granulation method in traditional Chinese medicine and by referring to the advanced research results of dry granulation technology in other fields,we would discuss the research ideas of dry granulation in traditional Chinese medicine in terms of the mechanism of dry granulation equipment,technology,on-line detection technology and mathematical model of dry granulation process,hoping to provide reference for the research of dry granulation method in traditional Chinese medicine.

The effectiveness of curvilinear supine position on the incidence of pressure injuries and interface pressure among surgical patients.

BACKGROUND: Intraoperative pressure injury is still a major problem of perioperative nursing. Reducing the peak interface pressure is a valid clinical intervention for reducing the incidence of intraoperative pressure injuries. However, studies of repositioning and pressure-redistributing for surgical patients are still lacking. In this context we aimed to evaluate the effect of a curvilinear supine position on incidence of pressure injury with surgical patients in a hospital setting. METHODS: This was a prospective, randomized, controlled study, carried out from May to December 2016, included 104 surgical patients from a university hospital in China (experimental group, n = 52; control group, n = 52). Incidence of pressure injury, interface pressure, comfort and satisfaction scores from surgeons, anesthesiologists, OR nurses were recorded. Mann-Whitney U Chi-square test was used for difference of pressure injury's incidence and mixed linear model was used for interface pressure. RESULTS: Overall the intervention group had significant fewer intraoperative pressure injuries than the control group (0 patients [0%] vs. 9 patients [17.65%], p = 0.002). Compared with control group, the experimental group had significantly lower interface pressures in the sacrum and heel regions (F = 23.81, p < 0.001; F = 60.71, p < 0.001). The subjects felt comfortable in two groups were 40(80%) vs. 3(5.88%) (experimental group vs. control group), respectively (p < 0.001). CONCLUSIONS: Curvilinear supine position could significantly decrease the incidence of perioperative pressure injuries in surgical patients with surgery duration more than three hours. Considering these results, we recommend that curvilinear supine position use as effective interventions to inform perioperative care delivery, reducing perioperative pressure injuries. These findings may serve to guide the application of pressure redistribution in the surgical positioning of patients during prolonged surgery.

Boron-Implanted Silicon Substrates for Physical Adsorption of DNA Origami.

DNA nanostructures routinely self-assemble with sub-10 nm feature sizes. This capability has created industry interest in using DNA as a lithographic mask, yet with few exceptions, solution-based deposition of DNA nanostructures has remained primarily academic to date. En route to controlled adsorption of DNA patterns onto manufactured substrates, deposition and placement of DNA origami has been demonstrated on chemically functionalized silicon substrates. While compelling, chemical functionalization adds fabrication complexity that limits mask efficiency and hence industry adoption. As an alternative, we developed an ion implantation process that tailors the surface potential of silicon substrates to facilitate adsorption of DNA nanostructures without the need for chemical functionalization. Industry standard 300 mm silicon wafers were processed, and we showed controlled adsorption of DNA origami onto boron-implanted silicon patterns; selective to a surrounding silicon oxide matrix. The hydrophilic substrate achieves very high surface selectivity by exploiting pH-dependent protonation of silanol-groups on silicon dioxide (SiO2), across a range of solution pH values and magnesium chloride (MgCl2) buffer concentrations.

Effects of Curvilinear Supine Position on Tissue Interface Pressure: A Prospective Before-and-After Study.

PURPOSE: To determine whether a curvilinear supine position increases the contact area between the subject and the surgical table, reduces interface pressures within contact areas, and improves comfort. DESIGN: This observational study was completed to establish proof-of-concept to determine differences between 2 positions (supine and curvilinear) on interface pressure of 5 at-risk anatomical locations, overall contact area, and subjects' comfort level. SUBJECTS AND SETTING: The study was conducted at the operating theater of a tertiary teaching hospital in Wuhan, China. The sample comprised 145 healthy Asian volunteers between 18 and 60 years of age. METHODS: Subjects were placed in the supine and curvilinear supine positions on a surgical table. Contact area and peak interface pressures of 5 at-risk anatomical locations (occiput, scapula, sacrum, calf, and heel) were measured using a pressure mapping system, and the mean and maximum pressures of the overall contact area were calculated. Comfort was assessed by self-report using a Likert scale of 1 to 5. The Wilcoxon paired signed rank test was used to compare differences between the 2 positions, and the Spearman correlation analysis was used to identify associations among outcome variables. RESULTS: Results indicated that whole-body (overall) maximum, average interface pressures, and maximum interface pressures of the sacrum and the heel were decreased significantly, with contact area and comfort-level score increasing from 2438.71 to 2709.68 cm and 3.00 to 4.00, respectively (P < .001). Statistically significant associations were found between the contact area and measures of body morphology; correlation coefficients varied from 0.409 to 0.740 (P < .001). CONCLUSIONS: Curvilinear supine position increased overall contact area with the support surface, reduced interface pressures over contact areas (bony prominences), improved comfort, and enhanced pressure redistribution. Additional research is needed to determine if these effects will reduce intraoperative pressure injury occurrence.

Twisting of DNA Origami from Intercalators.

DNA nanostructures represent the confluence of materials science, computer science, biology, and engineering. As functional assemblies, they are capable of performing mechanical and chemical work. In this study, we demonstrate global twisting of DNA nanorails made from two DNA origami six-helix bundles. Twisting was controlled using ethidium bromide or SYBR Green I as model intercalators. Our findings demonstrate that DNA nanorails: (i) twist when subjected to intercalators and the amount of twisting is concentration dependent, and (ii) twisting saturates at elevated concentrations. This study provides insight into how complex DNA structures undergo conformational changes when exposed to intercalators and may be of relevance when exploring how intercalating drugs interact with condensed biological structures such as chromatin and chromosomes, as well as chromatin analogous gene expression devices.

Metrology of DNA arrays by super-resolution microscopy.

Recent results in the assembly of DNA into structures and arrays with nanoscale features and patterns have opened the possibility of using DNA for sub-10 nm lithographic patterning of semiconductor devices. Super-resolution microscopy is being actively developed for DNA-based imaging and is compatible with inline optical metrology techniques for high volume manufacturing. Here, we combine DNA tile assembly with state-dependent super-resolution microscopy to introduce crystal-PAINT as a novel approach for metrology of DNA arrays. Using this approach, we demonstrate optical imaging and characterization of DNA arrays revealing grain boundaries and the temperature dependence of array quality. For finite arrays, analysis of crystal-PAINT images provides further quantitative information of array properties. This metrology approach enables defect detection and classification and facilitates statistical analysis of self-assembled DNA nanostructures.

DNA topology influences molecular machine lifetime in human serum.

DNA nanotechnology holds the potential for enabling new tools for biomedical engineering, including diagnosis, prognosis, and therapeutics. However, applications for DNA devices are thought to be limited by rapid enzymatic degradation in serum and blood. Here, we demonstrate that a key aspect of DNA nanotechnology-programmable molecular shape-plays a substantial role in device lifetimes. These results establish the ability to operate synthetic DNA devices in the presence of endogenous enzymes and challenge the textbook view of near instantaneous degradation.

Excitonic AND Logic Gates on DNA Brick Nanobreadboards.

A promising application of DNA self-assembly is the fabrication of chromophore-based excitonic devices. DNA brick assembly is a compelling method for creating programmable nanobreadboards on which chromophores may be rapidly and easily repositioned to prototype new excitonic devices, optimize device operation, and induce reversible switching. Using DNA nanobreadboards, we have demonstrated each of these functions through the construction and operation of two different excitonic AND logic gates. The modularity and high chromophore density achievable via this brick-based approach provide a viable path toward developing information processing and storage systems.

High precision and high yield fabrication of dense nanoparticle arrays onto DNA origami at statistically independent binding sites.

High precision, high yield, and high density self-assembly of nanoparticles into arrays is essential for nanophotonics. Spatial deviations as small as a few nanometers can alter the properties of near-field coupled optical nanostructures. Several studies have reported assemblies of few nanoparticle structures with controlled spacing using DNA nanostructures with variable yield. Here, we report multi-tether design strategies and attachment yields for homo- and hetero-nanoparticle arrays templated by DNA origami nanotubes. Nanoparticle attachment yield via DNA hybridization is comparable with streptavidin-biotin binding. Independent of the number of binding sites, >97% site-occupation was achieved with four tethers and 99.2% site-occupation is theoretically possible with five tethers. The interparticle distance was within 2 nm of all design specifications and the nanoparticle spatial deviations decreased with interparticle spacing. Modified geometric, binomial, and trinomial distributions indicate that site-bridging, steric hindrance, and electrostatic repulsion were not dominant barriers to self-assembly and both tethers and binding sites were statistically independent at high particle densities.

Chiral plasmonic DNA nanostructures with switchable circular dichroism.

Circular dichroism spectra of naturally occurring molecules and also of synthetic chiral arrangements of plasmonic particles often exhibit characteristic bisignate shapes. Such spectra consist of peaks next to dips (or vice versa) and result from the superposition of signals originating from many individual chiral objects oriented randomly in solution. Here we show that by first aligning and then toggling the orientation of DNA-origami-scaffolded nanoparticle helices attached to a substrate, we are able to reversibly switch the optical response between two distinct circular dichroism spectra corresponding to either perpendicular or parallel helix orientation with respect to the light beam. The observed directional circular dichroism of our switchable plasmonic material is in good agreement with predictions based on dipole approximation theory. Such dynamic metamaterials introduce functionality into soft matter-based optical devices and may enable novel data storage schemes or signal modulators.

Multiscaffold DNA origami nanoparticle waveguides.

DNA origami templated self-assembly has shown its potential in creating rationally designed nanophotonic devices in a parallel and repeatable manner. In this investigation, we employ a multiscaffold DNA origami approach to fabricate linear waveguides of 10 nm diameter gold nanoparticles. This approach provides independent control over nanoparticle separation and spatial arrangement. The waveguides were characterized using atomic force microscopy and far-field polarization spectroscopy. This work provides a path toward large-scale plasmonic circuitry.

Enhanced DNA sensing via catalytic aggregation of gold nanoparticles.

A catalytic colorimetric detection scheme that incorporates a DNA-based hybridization chain reaction into gold nanoparticles was designed and tested. While direct aggregation forms an inter-particle linkage from only one target DNA strand, catalytic aggregation forms multiple linkages from a single target DNA strand. Gold nanoparticles were functionalized with thiol-modified DNA strands capable of undergoing hybridization chain reactions. The changes in their absorption spectra were measured at different times and target concentrations and compared against direct aggregation. Catalytic aggregation showed a multifold increase in sensitivity at low target concentrations when compared to direct aggregation. Gel electrophoresis was performed to compare DNA hybridization reactions in catalytic and direct aggregation schemes, and the product formation was confirmed in the catalytic aggregation scheme at low levels of target concentrations. The catalytic aggregation scheme also showed high target specificity. This application of a DNA reaction network to gold nanoparticle-based colorimetric detection enables highly-sensitive, field-deployable, colorimetric readout systems capable of detecting a variety of biomolecules.

DNA-controlled excitonic switches.

Fluorescence resonance energy transfer (FRET) is a promising means of enabling information processing in nanoscale devices, but dynamic control over exciton pathways is required. Here, we demonstrate the operation of two complementary switches consisting of diffusive FRET transmission lines in which exciton flow is controlled by DNA. Repeatable switching is accomplished by the removal or addition of fluorophores through toehold-mediated strand invasion. In principle, these switches can be networked to implement any Boolean function.

Programmable periodicity of quantum dot arrays with DNA origami nanotubes.

To fabricate quantum dot arrays with programmable periodicity, functionalized DNA origami nanotubes were developed. Selected DNA staple strands were biotin-labeled to form periodic binding sites for streptavidin-conjugated quantum dots. Successful formation of arrays with periods of 43 and 71 nm demonstrates precise, programmable, large-scale nanoparticle patterning; however, limitations in array periodicity were also observed. Statistical analysis of AFM images revealed evidence for steric hindrance or site bridging that limited the minimum array periodicity.

Trihalomethane, haloacetonitrile, and chloral hydrate formation potentials of organic carbon fractions from sub-tropical forest soils.

Forest landscapes represent the major land-cover type for the watersheds of the East River, which is the source of water for 40 million people in South China. Forest soils with high levels of organic carbon are a potential terrestrial source of dissolved organic carbon (DOC) into the East River. DOC is of great concern, since it can form carcinogenic disinfection byproducts (DBPs) during drinking water treatment. In this study, soils from three altitudes (200, 450 and 900 m) in the Xiangtou Mountain Nature Reserve in South China, representing soils from evergreen moon forest, transitional evergreen broadleaf forest, and evergreen broadleaf forest, respectively, were evaluated for their potential contributions of DBP precursors into the East River. The water extractable organic carbon (WEOC) in three forest soils was physically and chemically fractionated into particulate organic carbon (1.2-0.45 microm), colloidal organic carbon (0.45-0.22 microm), and dissolved organic carbon (DOC) (<0.22 microm), hydrophobic acid (HPOA), transphilic acid and hydrophilic acid and were analysed for the formation potentials of trihalomethanes (THMs), haloacetonitriles (HANs), and chloral hydrate (CHD). Also, soils were incubated at 15, 25 and 35 degrees C for 14d in darkness to examine the impact of temperature effects on the availability and characteristics of WEOC. The extraction study showed that the amount of WEOC was proportional to soil organic carbon content, of which about 1% was water extractable. Regardless of soil type, DOC and HPOA were the most reactive fractions in forming THMs, CHD, and HANs. Production of DOC and HPOA in WEOC increased over 14 d incubation as incubation temperature increased, but the temperature did not alter the distribution of physical and chemical fractions and their reactivity in DBP formation. Results suggest higher inputs of DOC and DBP precursors from forest watersheds into source water may result in a warmer environment.