Self-Expansion Based Multi-Patterning for 2D Materials Fabrication beyond the Lithographical Limit.

Two-dimensional (2D) materials are promising successors for silicon transistor channels in ultimately scaled devices, necessitating significant research efforts to study their behavior at nanoscopic length scales. Unfortunately, current research has limited itself to direct patterning approaches, which limit the achievable resolution to the diffraction limit and introduce unwanted defects into the 2D material. The potential of multi-patterning to fabricate 2D materials features with unprecedented precision and low complexity at large scale is demonstrated here. By combining lithographic patterning of a mandrel and bottom-up self-expansion, this approach enables pattern resolution one order of magnitude below the lithographical resolution. In-depth characterization of the self-expansion double patterning (SEDP) process reveals the ability to manipulate the critical dimension with nanometer precision through a self-limiting and temperature-controlled oxidation process. These results indicate that the SEDP process can regain the quality and morphology of the 2D material, as shown by high-resolution microscopy and optical spectroscopy. This approach is shown to open up new avenues for research into high-performance, ultra-scaled 2D materials devices for future electronics.

Selective translation by alternative bacterial ribosomes.

Alternative ribosome subunit proteins are prevalent in the genomes of diverse bacterial species, but their functional significance is controversial. Attempts to study microbial ribosomal heterogeneity have mostly relied on comparing wild-type strains with mutants in which subunits have been deleted, but this approach does not allow direct comparison of alternate ribosome isoforms isolated from identical cellular contexts. Here, by simultaneously purifying canonical and alternative RpsR ribosomes from Mycobacterium smegmatis, we show that alternative ribosomes have distinct translational features compared with their canonical counterparts. Both alternative and canonical ribosomes actively take part in protein synthesis, although they translate a subset of genes with differential efficiency as measured by ribosome profiling. We also show that alternative ribosomes have a relative defect in initiation complex formation. Furthermore, a strain of M. smegmatis in which the alternative ribosome protein operon is deleted grows poorly in iron-depleted medium, uncovering a role for alternative ribosomes in iron homeostasis. Our work confirms the distinct and nonredundant contribution of alternative bacterial ribosomes for adaptation to hostile environments.

Synthesis and biological activity of pyridine acylhydrazone derivatives of isopimaric acid.

Pyridine acylhydrazone derivatives of isopimaric acid were synthesized and characterized. The minimum inhibitory concentrations of the compounds against five bacteria were determined and most of the compounds displayed some degree of antibacterial activity. The results showed that antimicrobial activity against Streptococcus pneumoniae improved when halogen atoms were introduced into the isopimaric acid, especially when one bromine atom was introduced in the para-position of isopimaric acid. Compound isopimaric acid (5-bromo pyridine-2-formaldehyde) acylhydrazone exhibited a significant antitumorial activity against hepatocarcioma cells (HepG-2) and breast cancer cells (MDA-MB-231), with inhibition degrees of 74.21% and 70.39%, respectively, at 100 µM.[Formula: see text].

Isolation and characterization of cDNAs and genomic DNAs encoding ADP-glucose pyrophosphorylase large and small subunits from sweet potato.

Sweet potato [Ipomoea batatas (L.) Lam.], the world's seventh most important food crop, is also a major industrial raw material for starch and ethanol production. In the plant starch biosynthesis pathway, ADP-glucose pyrophosphorylase (AGPase) catalyzes the first, rate-limiting step and plays a pivotal role in regulating this process. In spite of the importance of sweet potato as a starch source, only a few studies have focused on the molecular aspects of starch biosynthesis in sweet potato and almost no intensive research has been carried out on the AGPase gene family in this species. In this study, cDNAs encoding two small subunits (SSs) and four large subunits (LSs) of AGPase isoforms were cloned from sweet potato and the genomic organizations of the corresponding AGPase genes were elucidated. Expression pattern analysis revealed that the two SSs were constitutively expressed, whereas the four LSs displayed differential expression patterns in various tissues and at different developmental stages. Co-expression of SSs with different LSs in Escherichia coli yielded eight heterotetramers showing different catalytic activities. Interactions between different SSs and LSs were confirmed by a yeast two-hybrid experiment. Our findings provide comprehensive information about AGPase gene sequences, structures, expression profiles, and subunit interactions in sweet potato. The results can serve as a foundation for elucidation of molecular mechanisms of starch synthesis in tuberous roots, and should contribute to future regulation of starch biosynthesis to improve sweet potato starch yield.

Harnessing Quantum Capacitance in 2D Material/Molecular Layer Junctions for Novel Electronic Device Functionality.

Two-dimensional (2D) materials promise advances in electronic devices beyond Moore's scaling law through extended functionality, such as non-monotonic dependence of device parameters on input parameters. However, the robustness and performance of effects like negative differential resistance (NDR) and anti-ambipolar behavior have been limited in scale and robustness by relying on atomic defects and complex heterojunctions. In this paper, we introduce a novel device concept that utilizes the quantum capacitance of junctions between 2D materials and molecular layers. We realized a variable capacitance 2D molecular junction (vc2Dmj) diode through the scalable integration of graphene and single layers of stearic acid. The vc2Dmj exhibits NDR with a substantial peak-to-valley ratio even at room temperature and an active negative resistance region. The origin of this unique behavior was identified through thermoelectric measurements and ab initio calculations to be a hybridization effect between graphene and the molecular layer. The enhancement of device parameters through morphology optimization highlights the potential of our approach toward new functionalities that advance the landscape of future electronics.

Selective activation of MoS2 grain boundaries for enhanced electrochemical activity.

Molybdenum disulfide (MoS2) has emerged as a promising material for catalysis and sustainable energy conversion. However, the inertness of its basal plane to electrochemical reactions poses challenges to the utilization of wafer-scale MoS2 in electrocatalysis. To overcome this limitation, we present a technique that enhances the catalytic activity of continuous MoS2 by preferentially activating its buried grain boundaries (GBs). Through mild UV irradiation, a significant enhancement in GB activity was observed that approaches the values for MoS2 edges, as confirmed by a site-selective photo-deposition technique and micro-electrochemical hydrogen evolution reaction (HER) measurements. Combined spectroscopic characterization and ab-initio simulation demonstrates substitutional oxygen functionalization at the grain boundaries to be the origin of this selective catalytic enhancement by an order of magnitude. Our approach not only improves the density of active sites in MoS2 catalytic processes but yields a new photocatalytic conversion process. By exploiting the difference in electronic structure between activated GBs and the basal plane, homo-compositional junctions were realized that improve the photocatalytic synthesis of hydrogen by 47% and achieve performances beyond the capabilities of other catalytic sites.

Mechanical morphotype switching as an adaptive response in mycobacteria.

Invading microbes face a myriad of cidal mechanisms of phagocytes that inflict physical damage to microbial structures. How intracellular bacterial pathogens adapt to these stresses is not fully understood. Here, we report the discovery of a virulence mechanism by which changes to the mechanical stiffness of the mycobacterial cell surface confer refraction to killing during infection. Long-term time-lapse atomic force microscopy was used to reveal a process of "mechanical morphotype switching" in mycobacteria exposed to host intracellular stress. A "soft" mechanical morphotype switch enhances tolerance to intracellular macrophage stress, including cathelicidin. Both pharmacologic treatment, with bedaquiline, and a genetic mutant lacking uvrA modified the basal mechanical state of mycobacteria into a soft mechanical morphotype, enhancing survival in macrophages. Our study proposes microbial cell mechanical adaptation as a critical axis for surviving host-mediated stressors.

[Analysis of O3 Sources in Yulin City in Summer Based on WRF-CMAQ/ISAM Model].

In order to have a clearer understanding of the sources of ozone pollution in Yulin City in summer and put forward scientific governance suggestions, the WRF-CMAQ model was used to simulate the O3 concentration in Yulin City and surrounding areas (including Taiyuan City, Xi'an City, Yinchuan City, Hohhot City, and other provincial capital cities) in July 2019. Using the ISAM module, the sources of O3 and its precursors NOx and VOCs in a heavy pollution process in Yulin City were quantified. The results showed that on heavy pollution days, the O3 in Yulin City mainly came from the long-distance transmission outside the simulation area (55.5%), followed by the photochemical reaction of precursors in the simulation area (20.6%, 10.0%, 5.0%, 2.3%, and 2.1%, respectively, in Yulin City, Shanxi Province, Inner Mongolia Autonomous Region, and Shaanxi Province, 1.2% in Gansu Province, Ningxia Hui Autonomous Region, and Henan Province in total), and initial conditions (0.3%); the remaining sources (23.6%) could not be successfully labeled. Yulin City is in the VOCs control area, and its VOCs were composed of paraffin (76.5%), ketones (9.2%), and other types of VOCs (14.3%). The VOCs came from the emission of pollution sources in the simulation area (45.6%, 22.0%, 11.4%, 6.3%, and 5.1%, respectively, in Yulin City, Shanxi Province, Inner Mongolia Autonomous Region, and Shaanxi Province, 0.8% in Gansu Province, Ningxia Hui Autonomous Region, and Henan Province in total) and the long-distance transmission outside the simulation area (27.9%); the remaining 26.5% were not successfully marked. This research showed that to control the O3 pollution in Yulin, not only should the local VOCs emissions be controlled, but the overall planning of VOCs emissions in the peripheral areas should also be done well.

[Analysis of Causes and Sources of Summer Ozone Pollution in Rizhao Based on CMAQ and HYSPLIT Models].

As a typical coastal city, O3 pollution in Rizhao has become increasingly serious in recent years. In order to explore the causes and sources of O3 pollution, IPR process analysis and ISAM source tracking tools based on the CMAQ model were used, respectively, to quantify the contributions of different physicochemical processes and different source tracking areas to O3 in Rizhao. Additionally, by comparing the differences between O3-exceeding days and non-exceeding days, combined with the HYSPLIT model, the regional transportation path of O3 in Rizhao was explored. The results showed that the concentrations of O3, NOx, and VOCs near the coastal areas of Rizhao and Lianyungang were significantly increased on O3 exceedance days compared with those on non-exceedance days. This was mainly because Rizhao was the convergence zone of western, southwestern, and eastern winds on exceedance days, which facilitated the transport and accumulation of pollutants. Process analysis showed that the transport process (TRAN) contribution to the near-surface O3 near the coastal areas of Rizhao and Lianyungang increased significantly on the exceedance days, whereas the contribution to most areas to the west of Linyi decreased. Photochemical reaction (CHEM) had a positive contribution to the O3 concentration in Rizhao during the daytime at all heights, and TRAN had a positive contribution at 0-60 m above the ground, and mainly had a negative contribution above 60 m. The contributions of CHEM and TRAN at 0-60 m above the ground would increase significantly on exceedance days, which was approximately twice that on the non-exceedance days. Source analysis showed that the local sources in Rizhao were the main contribution sources of NOx and VOCs, with the contribution rates of 47.5% and 58.0%, respectively. O3 mainly came from the contribution outside the simulation area (67.5%). The O3 and precursor contributions of the western cities of Rizhao (Weifang, Linyi, etc.) and the southern cities (Lianyungang, etc.) would increase significantly on the days of exceeding the standard. The transportation path analysis showed that the number of exceedances accounted for the largest proportion (11.8%) in the path from the west of Rizhao, which was the main transportation channel of O3 and precursors in Rizhao. This was verified through process analysis and source tracking results, and such trajectories accounted for 13.0% of the total number of trajectories, and their main routes were in the Shaanxi, Shanxi, Hebei, and Shandong regions.

Improving the Physical Properties of Starch-Based Powders for Potential Anti-Adhesion Applications.

Postoperative adhesion is one of the most common complications that occur during and after surgery; thus, materials that can prevent adhesion are often applied. Starch powders with a high water absorption capacity are preferred, and many studies have focused on increasing the water absorption of modified starches, as native starch powders display poor water-holding capacities. The effects of salts on the physical properties of acetylated distarch phosphate potato starch powders were investigated here. Changes in functional groups, the crystal structures of modified starch, particle morphologies, water absorption, viscosity, and in vivo adhesion were investigated. The results showed that salts greatly improved the water absorption and viscosity of acetylated distarch phosphate potato starch powders. Among the three different salt-modified starch powders, NaCl-modified starch powders displayed higher water absorption and viscosity and demonstrated better in vivo anti-adhesion performance. The results of this study propose a potential biomaterial that may function as an anti-adhesive, potentially leading to reduced surgical risks and a better quality of life for patients.

Metal-organic framework-derived nitrogen-doped carbon-confined CoSe2 anchored on multiwalled carbon nanotube networks as an anode for high-rate sodium-ion batteries.

Metal selenides, as potential alternative candidates for sodium storage, have promising applicability due to their high theoretical specific capacity. However, their huge volume change and sluggish electrode kinetics during sodium ion uptake and release processes can result in insufficient cycling life and inferior rate performance, hindering their practical application. Herein, nitrogen (N)-doped carbon-confined cobalt selenide anchored on multiwalled carbon nanotube networks (denoted as CoSe2@NC/MWCNTs) was designed and successfully built through a selenization process with ZIF-67 MOF as the template. The existence of the interconnected MWCNT network plays a crucial role in not only enhancing the electronic conductivity and ion/electron-transfer efficiency but also ensuring structural stability. Consequently, the optimized CoSe2@NC/MWCNTs composite delivers a high reversible capacity of 479.6 mA h g-1 at a current rate of 0.2 A g-1, accompanied by a 92.0% capacity retention over 100 cycles and a predominant rate performance of 227.4 mA h g-1 even under 20 A g-1 when examined as the anode in Na-ion batteries. Moreover, the kinetic behaviors were confirmed using CV profiles at various rates, as well as the galvanostatic intermittent titration technique (GITT) and electrochemical impedance spectroscopy (EIS). Besides, the HRTEM images clearly reveal the sodium-ion storage mechanism of the CoSe2 hybrid. These results make CoSe2@NC/MWCNTs a prospective anode material in advanced sodium-ion batteries.

Safety of Bivalirudin Combined with Ticagrelor in the Emergency PCI in Patients with Acute ST-Segment Elevation Myocardial Infarction.

OBJECTIVE: The present study aimed to investigate the application safety of bivalirudin combined with ticagrelor in the emergency percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). METHODS: From October 1, 2018, to December 30, 2019, 210 patients with STEMI admitted to the Department of Cardiology who underwent emergency PCI were randomly divided into the bivalirudin group (group A, N = 105) and the unfractionated heparin group (group B, N = 105). Before the emergency PCI operation after admission, the loading dose of aspirin (300 mg) was given orally, and then 100 mg/d. At the same time, the loading dose of ticagrelor (180 mg) was administered orally, and then 90 mg/bid. The adverse events and the hemorrhage events 30 days after the operation were observed and recorded. RESULTS: There were five hemorrhage cases in the bivalirudin group, with one case of secondary hemorrhage and four cases of mild hemorrhage. There were 14 hemorrhages in the unfractionated heparin group with one case of secondary hemorrhage and thirteen cases of mild hemorrhage. In terms of mild hemorrhage, the hemorrhage rate in the bivalirudin group was significantly lower than that in the unfractionated heparin group (3.8% vs. 12.4%, P = 0.040). One patient died in the unfractionated heparin group, while no deaths occurred in the bivalirudin group during the thirty days of follow-up. No myocardial infarction, revascularization, or stroke occurred in the two groups within 30 days after the operation. CONCLUSION: Compared with unfractionated heparin combined with ticagrelor in patients with STEMI undergoing emergency PCI treatment, bivalirudin combined with ticagrelor could significantly reduce the occurrence of mild hemorrhage events, and it would not increase the incidence of MACE during the 30 days of follow-up.

Succession of endophytic bacterial community and its contribution to cinnamon oil production during cinnamon shade-drying process.

Cinnamon oil is a blend of secondary metabolites and is widely used as spice. Endophytic bacteria are always related to the secondary metabolites production. However, the potential of endophytic bacteria communities for cinnamon oil production during cinnamon shade-drying process is still not clear. In this study, we investigated the composition and metabolic function of endophytic bacterial community during 80-day shade-drying process. The temporal dynamics of essential oil content and its dominant constituents were analyzed. The succession of endophytic bacterial community from d0 to d80 was identified. The influence of endophytic bacterial community evolution on cinnamon oil is significant positive. Predictive functional analysis indicated that shade-drying process was rich in Saccharopolyspora that produce enzymes for the conversion of phenylalanine to cinnamaldehyde. These findings enhance our understanding of the functional bacterial genera and functional genes involved in the production of cinnamon oil during cinnamon shade-drying process.

Treatment of hepatic venous system hemorrhage and carbon dioxide gas embolization during laparoscopic hepatectomy via hepatic vein approach.

With the improvement of laparoscopic surgery, the feasibility and safety of laparoscopic hepatectomy have been affirmed, but intraoperative hepatic venous system hemorrhage and carbon dioxide gas embolism are the difficulties in laparoscopic hepatectomy. The incidence of preoperative hemorrhage and carbon dioxide gas embolism could be reduced through preoperative imaging evaluation, reasonable liver blood flow blocking method, appropriate liver-breaking device, controlled low-center venous pressure technology, and fine-precision precision operation. In the case of blood vessel rupture bleeding in the liver vein system, after controlling and reducing bleeding, confirm the type and severity of vascular damage in the liver and venous system, take appropriate measures to stop the bleeding quickly and effectively, and, if necessary, transfer the abdominal treatment in time. In addition, to strengthen the understanding, prevention and emergency treatment of severe CO2 gas embolism in laparoscopic hepatectomy is also the key to the success of surgery. This study aims to investigate the methods to deal with hepatic venous system hemorrhage and carbon dioxide gas embolization based on author's institutional experience and relevant literature. We retrospectively analyzed the data of 60 patients who received laparoscopic anatomical hepatectomy of hepatic vein approach for HCC. For patients with intraoperative complications, corresponding treatments were given to cope with different complications. After the operation, combined with clinical experience and literature, we summarized and discussed the good treatment methods in the face of such situations so that minimize the harm to patients as much as possible.

Three-dimensional microspheres constructed with MoS2 nanosheets supported on multiwalled carbon nanotubes for optimized sodium storage.

Molybdenum disulfide (MoS2) has been regarded as a promising anode material in the field of sodium-ion batteries (SIBs), with the advantages of high theoretical capacity and large interlayer spacings. Unfortunately, its intrinsic poor electrical conductivity and large volume changes during the sodiation/desodiation reactions still limit its practical application. To deal with this shortcoming, we built MoS2 nanosheet/multiwalled carbon nanotube (denoted as MoS2-MSs/MWCNTs) composites with a three-dimensional (3D) micro-spherical structure, assembled in situ from MoS2 nanosheets. These nanosheets are connected to each other by the MWCNTs network, which provides a highly conductive pathway for electrons/ions through interparticle and intraparticle interfaces, accelerating charge transfer and ion diffusion capabilities. More importantly, the carbon network can boost electrical conductivity and relieve structural strain. Consequently, the as-prepared MoS2-MSs/MWCNTs composite presents a high reversible specific capacity of 519 mA h g-1 at 0.1 A g-1 after 100 cycles with a capacity retention of 94.4% and excellent rate performance (227 mA h g-1 at 10 A g-1). Outstanding cycling stability was also achieved (327.1 mA h g-1 over 1000 cycles at 2 A g-1) and was characterized by scanning electron microscopy (SEM) analysis. Our findings provide a simple and effective strategy to explore anode materials with advanced sodium storage properties.

Preoperative Prognostic Nutritional Index and Neutrophil-to-Lymphocyte Ratio Predict Survival Outcomes of Patients With Hepatocellular Carcinoma After Curative Resection.

Increasing evidence indicates that preoperative prognostic indices can serve as independent predictors of survival in patients with cancer. However, the applicability of these indices in patients with hepatocellular carcinoma (HCC) is controversial. This study aims to investigate the prognostic value of these indices in patients with HCC after curative hepatectomy. We retrospectively analyzed the data of 215 patients who underwent curative resection for HCC. Prognostic indices including prognostic nutritional index (PNI) and neutrophil-to-lymphocyte ratio (NLR) were evaluated by comparing by the area under the curve (AUC). Univariate analysis and multivariate analysis were performed to identify independent prognostic factors. Additionally, risk factors were combined to predict the survival of patients. We found that serum albumin concentration, tumor diameter, tumor stage, degree of differentiation, PNI, and NLR were independent prognostic factors for overall survival (OS). Vascular invasion, tumor stage, degree of differentiation, and PNI were independent prognostic factors for recurrence-free survival (RFS). The cutoff value of the PNI and NLR was 43.75 and 3.29, respectively. Patients with low NLR and high PNI had the best outcomes, potentially indicative of the intensive antitumor effects of the immune system. Moreover, patients with at least three risk factors had a significantly lower OS and RFS compared with those with two or fewer risk factors. This new nomogram based on PNI and NLR may provide an accessible and individualized prediction of survival and recurrence for HCC patients.

1,4a,7-Trimethyl-7-vinyl-1,2,3,4,4a,4b,5,6,7,8,10,10a-dodeca-hydro-phenanthrene-1-carboxylic acid.

The title compound, also known as isopimaric acid, C(20)H(30)O(2), was isolated from slash pine rosin. There are two unique mol-ecules in the unit cell. The two cyclo-hexane rings have classical chair conformations. The cyclo-hexene ring represents a semi-chair. The mol-ecular conformation is stabilized by weak intra-molecular C-H⋯O hydrogen-bonding inter-actions. The mol-ecules are dimerized through their carboxyl groups by O-H⋯O hydrogen bonds, forming R(2) (2)(8) rings.

1,4a,7-Trimethyl-7-vinyl-1,2,3,4,4a,4b,5,6,7,9,10,10a-dodeca-hydro-phenanthrene-1-carboxylic acid.

The title compound, pimaric acid, C(20)H(30)O(2), was isolated from a mixture of resin acids. There are three rings in the structure. The two cyclo-hexane rings have classical chair conformations with trans-fused ring junctions. The cyclo-hexene ring appears as a semi-chair.

(E)-(4-Chloro-benzyl-idene){[(1R,4aS,10aR)-7-isopropyl-1,4a-dimethyl-1,2,3,4,4a,9,10,10a-octa-hydro-1-phenanthryl]-methyl}amine.

The title compound, C(27)H(34)ClN, has been synthesized from 4-chloro-benzaldehyde and dehydro-abietylamine. There are two unique mol-ecules in the unit cell. Each mol-ecule has three chiral centres, which exhibit R, S and R absolute configurations. The two cyclo-hexane rings form a trans ring junction with classical chair and half-chair conformations.

Measurement of Specific Mycobacterial Mistranslation Rates with Gain-of-function Reporter Systems.

The translation of genes into proteins is prone to errors. Although the average rate of translational error in model systems is estimated to be 1/10,000 per codon, the actual error rates vary widely, depending on the species, environment, and codons being studied. We have previously shown that mycobacteria use a two-step pathway for the generation of aminoacylated glutamine and asparagine tRNAs and that this is specifically associated with relatively high error rates due to the modulation of mistranslation rates by an essential component of the pathway, the amidotransferase GatCAB. We modified a previously employed Renilla-Firefly dual-luciferase system that had been used to measure mistranslation rates in Escherichia coli for use in mycobacteria to measure specific mistranslation rates of glutamate at glutamine codons and aspartate for asparagine codons. Although this reporter system was suitable for the accurate estimation of specific error rates, lack of sensitivity and requirements for excessive manipulation steps made it unsuitable for high-throughput applications. Therefore, we developed a second gain-of-function reporter system, using Nluc luciferase and green fluorescent protein (GFP), which is more amenable to medium/high-throughput settings. We used this system to identify kasugamycin as a small molecule that can decrease mycobacterial mistranslation. Although the reporters that we describe here have been used to measure specific types of mycobacterial mistranslation, they may be modified to measure other types of mistranslation in a number of model systems.