Adaptive phase retrieval algorithm for local highlight area based on a piecewise sine function.

Phase measuring profilometry (PMP) has been widely used in industries for three-dimensional (3D) shape measurement. However, phase information is often lost due to image saturation results from high-reflection object surfaces, leading to subsequent 3D reconstruction errors. To address the problem, we propose an adaptive phase retrieval algorithm that can accurately fit the sinusoidal fringes damaged by high reflection in the saturated regions to retrieve the lost phase information. Under the proposal, saturated regions are first identified through a minimum error thresholding technique to narrow down regions of interest and so that computation costs are reduced. Then, images with differing exposures are fused to locate peak-valley coordinates of the fitting sinusoidal fringes. And the corresponding values of peak-valley pixels are obtained based on a least squares method. Finally, an adaptive piecewise sine function is constructed to recover the sinusoidal fringe pattern by fitting the pattern intensity distribution. And the existing PMP technology is used to obtain phase information from the retrieved sinusoidal fringes. To apply the developed method, only one (or two) image with different exposure times is needed. Compared with existing methods for measuring reflective objects, the proposed method has the advantages of short operation time, reduced system complexity, and low demand on hardware equipment. The effectiveness of the proposed method is verified through two experiments. The developed methodology provides industry an alternative way to measure high-reflection objects in a wide range of applications.

Dynamic Interconversions of Single Molecules Probed by Recognition Tunneling at Cucurbit[7]uril-Functionalized Supramolecular Junctions.

We introduce a versatile recognition tunneling technique using doubly cucurbit[7]uril-functionalized electrodes to form supramolecular junctions that capture analytes dynamically by host-guest complexation. This results in characteristic changes in their single-molecule conductance. For structurally related drug molecules (camptothecin, sanguinarine, chelerythrine, and berberine) and mixtures thereof, we observed distinct current switching signals related to their intrinsic conductance properties as well as pH-dependent effects which can be traced back to their different states (protonated versus neutral). The conductance variation of a single molecule with pH shows a sigmoidal distribution, allowing us to extract a pKa value for reversible protonation, which is consistent with the reported macroscopic results. The new electronic method allows the characterization of unmodified drug molecules and showcases the transfer of dynamic supramolecular chemistry principles to single molecules.

Direct Observation of Amide Bond Formation in a Plasmonic Nanocavity Triggered by Single Nanoparticle Collisions.

The real-time observation of chemical bond formation at the single-molecule level is one of the great challenges in the fields of organic and biomolecular chemistry. Valuable information can be gleaned that is not accessible using ensemble-average measurements. Although remarkably sophisticated techniques for monitoring chemical reactions have been developed, the ability to detect the specific formation of a chemical bond in situ at the single-molecule level has remained an elusive goal. Amide bonds are routinely formed from the aminolysis of N-hydroxysuccinimide (NHS) esters by primary amines, and the protocol is widely used for the synthesis, cross-linking, and labeling of peptides and proteins. Herein, a plasmonic nanocavity was applied to study aminolysis reaction for amide bond formation, which was initiated by single nanoparticle collision events between suitably functionalized free-moving gold nanoparticles and a gold nanoelectrode in an aqueous buffer. By means of simultaneous surface enhanced Raman spectroscopy (SERS) and single-entity electrochemistry (EC) measurements, we have probed the dynamic evolution of amide bond formation in the aminolysis reaction with 10 s of millisecond time resolution. Hence, we demonstrate that single-entity EC-SERS is a valuable and sensitive technique by which chemical reactions can be studied at the single-molecule level.

Modulating and probing the dynamic intermolecular interactions in plasmonic molecule-pair junctions.

Reversible intermolecular interactions play critical roles in nature. However, it is still challenging to monitor the dynamic intermolecular interactions at the single-molecule level in aqueous solution. Here, we studied the dynamic changes of intermolecular interactions at the carboxyl/carboxyl interfaces between a pair of molecules trapped in a plasmonic nanocavity formed between a gold nanoparticle (GNP) and a gold nanoelectrode (GNE). The development of intermolecular interactions, including the appearance of hydrogen bonds (h-bonds), during and after single GNP collision events on the GNE, was monitored by time-resolved surface-enhanced Raman spectroscopy at a tens of milliseconds time resolution. Spectral fingerprints of the carboxyl group corresponding to non-specific intermolecular interactions and h-bonds are identified. Furthermore, we demonstrated that the strength of intermolecular interaction could be mechanically modulated by changing the applied bias at the GNE, which resulted in small and controllable changes in the nanogap distance. Unlike non-specific intermolecular interactions, the intermolecular h-bonds can only be formed stochastically and are more sensitive to the gap distance modulation. This report demonstrates a new approach to modulate and probe intermolecular interactions within nanogaps.

Cucurbituril mediated single molecule detection and identification via recognition tunneling.

Recognition tunneling (RT) is an emerging technique for investigating single molecules in a tunnel junction. We have previously demonstrated its capability of single molecule detection and identification, as well as probing the dynamics of intermolecular bonding at the single molecule level. Here by introducing cucurbituril as a new class of recognition molecule, we demonstrate a powerful platform for electronically investigating the host-guest chemistry at single molecule level. In this report, we first investigated the single molecule electrical properties of cucurbituril in a tunnel junction. Then we studied two model guest molecules, aminoferrocene and amantadine, which were encapsulated by cucurbituril. Small differences in conductance and lifetime can be recognized between the host-guest complexes with the inclusion of different guest molecules. By using a machine learning algorithm to classify the RT signals in a hyper dimensional space, the accuracy of guest molecule recognition can be significantly improved, suggesting the possibility of using cucurbituril molecule for single molecule identification. This work enables a new class of recognition molecule for RT technique and opens the door for detecting a vast variety of small molecules by electrical measurements.

ASF1B acted as a prognostic biomarker for stomach adenocarcinoma.

Stomach adenocarcinoma (STAD) has a high mortality rate due to the lack of highly sensitive biomarkers. Therefore, the search for potential tumor markers is of great value. ASF1B is a prognostic marker for a variety of tumors, while the prognostic value and immune microenvironment of ASF1B in STAD remain unclear, and to be determined. Kaplan-Meier analysis was performed to analyze the prognostic role of ASF1B in STAD. Functional enrichment of ASF1B was explored with GO and KEGG pathway analysis. We also explored the correlation between ASF1B expression and immune infiltration in STAD. ASF1B was significantly upregulated in STAD tissues and high expression of ASF1B indicated a poor overall survival, progression-free survival, and first progression rate in STAD. The functional enrichment analysis of ASF1B and related genes showed high enrichment in the cell cycle and DNA repair, and the ASF1B high expression group was also mainly enriched in pathways such as the cell cycle. Analysis of tumor immune infiltration showed that ASF1B expression was significantly associated with the majority of immune cell infiltration in STAD. Moreover, STAD patients with high ASF1B expression had a higher tumor mutation burden score, microsatellite instability score, PD-1 immunophenoscore, and immune checkpoint expression. Our results suggest that ASF1B was an independent prognostic factor for STAD as well as a potential target for immunotherapy.

The Photocatalytic Activity of CaTiO3 Derived from the Microwave-Melting Heating Process of Blast Furnace Slag.

The extraction of titanium-bearing components in the form of CaTiO3 is an efficient utilization of blast furnace slag. The photocatalytic performance of this obtained CaTiO3 (MM-CaTiO3) as a catalyst for methylene blue (MB) degradation was evaluated in this study. The analyses indicated that the MM-CaTiO3 had a completed structure with a special length-diameter ratio. Furthermore, the oxygen vacancy was easier to generate on a MM-CaTiO3(110) plane during the photocatalytic process, contributing to improving photocatalytic activity. Compared with traditional catalysts, MM-CaTiO3 has a narrower optical band gap and visible-light responsive performance. The degradation experiments further confirmed that the photocatalytic degradation efficiency of pollutants by using MM-CaTiO3 was 3.2 times that of pristine CaTiO3 in optimized conditions. Combined with molecular simulation, the degradation mechanism clarified that acridine of MB molecular was stepwise destroyed by using MM-CaTiO3 in short times, which is different from demethylation and methylenedioxy ring degradation by using TiO2. This study provided a promising routine for using solid waste to obtain catalysts with excellent photocatalytic activity and was found to be in keeping with sustainable environmental development.

Plasmon-mediated dehydrogenation of the aromatic methyl group and benzyl radical formation.

Plasmonic molecular junctions can harvest visible light and effectively catalyze chemical reactions. The strong light field concentrated in the plasmonic junction also enables the application of surface enhanced Raman spectroscopy (SERS) to probe the catalyzed chemical reactions in situ and in real time down to single-molecule resolution. The benzyl radical produced from the aromatic methyl group through the dehydrogenation reaction is an important precursor for a large variety of reactions. Here, we used time-resolved SERS to conduct a mechanistic study of the plasmon-driven dehydrogenation reaction of the aromatic methyl group under ambient conditions under the illumination of red light on the apex of a gold nanoelectrode. Transient spectral changes with intensity bursts are frequently observed. Based on density functional theory and picocavity based local electric field enhancement calculations, they result from the plasmon mediated dehydrogenation reaction of aromatic methyl groups. The dehydrogenation reaction produces a benzyl radical, which is consequently converted to a benzyl anion. The benzyl anion is stabilized through strong interactions with gold, leading to the formation of dynamic gold adatoms and picocavities. In addition to the benzyl anion, we found spectral evidence that the benzyl radical generates dimers through a self-reaction. Furthermore, we demonstrated that the dehydrogenation reaction could be facially modulated by changing the electrode potential, which is attributed to the modulated inductive effect.

Case report: Acute ischemic stroke caused by intracranial artery dissection in a patient with skull fractures.

The intracranial artery dissection (IAD) is an uncommon but life-threatening disease. The IAD would develop a significant cerebral infarction due to unrecognized contrecoup brain injury. We report a 53-year-old man fell to develop blunt cerebrovascular injuries (BCVIs) more than 2 months ago. During his rehabilitation, he often had a transient left headache and underwent short-term right limb weakness twice, but he did not care. He was hospitalized again because of suffering right limb weakness for more than 4 h. The brain computed tomography angiography (CTA) showed subtotal occlusion of the left middle cerebral artery M1 segment, and the vascular morphology displayed the IAD. The patient was then treated with balloon dilation and a self-expanding stent. This case highlights that IAD may show delayed onset with no initial typical symptom. By early detecting of abnormal signs and symptoms, serious traumatic brain injury may be avoided.

Observing dynamic molecular changes at single-molecule level in a cucurbituril based plasmonic molecular junction.

In recent years, surface enhanced Raman spectroscopy (SERS) has emerged as a prominent tool for probing molecular interaction and reaction with single-molecule sensitivity. Here we use SERS to investigate the dynamic changes of the cucurbit[7]uril (CB[7]) based plasmonic molecular junctions in solution, which are spontaneously formed by the adsorption of gold nanoparticles (GNPs) at the CB[7] modified gold nanoelectrode (GNE) surface. The typical fingerprint Raman peaks of CB[7] are very weak in the SERS spectra. However, chemically enhanced peaks are prominent in the spectra due to the charge transfer across the metal-molecule interface through specific noncovalent interactions between the gold atoms and CB[7] or its guest molecule. We first investigated the selectively enhanced and greatly shifted C[double bond, length as m-dash]O peak of CB[7] in the SERS spectra. Based on the bias-dependent changes of the C[double bond, length as m-dash]O peak, we found the gold-carbonyl interaction was strengthened by the positive bias applied to the GNE, resulting in stable CB[7] junctions. Next, we found the CB[7] junction could also be stabilized by the inclusion of a guest molecule amino-ferrocene, attributed to the interactions between gold adatoms and the cyclopentadienyl ring of the guest molecule. Because this interaction is sensitive to the orientation of the guest molecule in the cavity, we revealed the rotational motion of a guest molecule inside the CB[7] cavity based on the dynamic spectral changes of the cyclopentadienyl ring peak.

"D2 plus" lymphadenectomy is associated with improved survival in distal gastric cancer with clinical serosa invasion: a propensity score analysis.

The aim of this study was to elucidate the potential impact of "D2 plus" lymphadenectomy on the long-term survival of distal gastric cancer (GC) patients with clinical serosa invasion. A total of 394 distal GC patients with clinical serosa invasion who underwent at least standard D2 lymphadenectomy were enrolled. Patients were categorized into two groups according to the extent of lymphadenectomy: D2 group and "D2 plus" group. Propensity score matching was used to adjust for the differences in baseline characteristics. In the multivariate analysis for the whole study series, extent of lymphadenectomy was an independent prognostic factor for GC patients (P = 0.011). With the strata analysis, the significant prognostic differences between the two groups were only observed in patients at the IIIa-b or N1-3a stages. After matching, patients in "D2 plus" group still demonstrated a significantly higher 5-year overall survival rate than those in D2 group (55.3% versus 43.9%, P = 0.042). The common therapeutic value index of No. 12b, No. 12p, No. 14v and No. 13 LNs was 4.6, which was close to that of No. 5 LN station. In conclusion, "D2 plus" lymphadenectomy may be associated with improved overall survival in distal GC with clinical serosa invasion.