DNA-based doping and fabrication of PN diodes

This paper reports the fabrication of silicon PN diode by using DNA nanostructure as the etching template for SiO2 and also as the n-dopant of Si. DNA nanotubes were deposited onto p-type silicon wafer that has a thermal SiO2 layer. The DNA nanotubes catalyze the etching of SiO2 by HF vapor to expose the underlying Si. The phosphate groups in the DNA nanotube were used as the doping source to locally n-dope the Si wafer to form vertical P-N junctions. Prototype PN diodes were fabricated and exhibited expected blockage behavior with a knee voltage of ca. 0.7 V. Our work highlights the potential of DNA nanotechnology in future fabrication of nanoelectronics

Multikingdom interactions govern the microbiome in subterranean cultural heritage sites

9 páginas.- 5 figuras.- 66 referencias.- Data Availability. The amplicon sequences, shotgun metagenomics, and screened Actinobacteria strain sequences reported in this article have been deposited in the NCBI BioProject and GenBank databases (accession nos. PRJNA721777, PRJNA745276, and OL444665 to OL444682, respectively). All other study data are included in the article and/or supporting informationMicrobial biodeterioration is a major concern for the conservation of historical cultural relics worldwide. However, the ecology involving the origin, composition, and establishment of microbiomes on relics, once exposed to external environments, is largely unknown. Here, we combined field surveys with physiological assays and biological interaction experiments to investigate the microbiome in the Dahuting Han Dynasty Tomb, a Chinese tomb with more than 1,800 y of history, and its surrounding environments. Our investigation finds that multikingdom interactions, from mutualism to competition, drive the microbiome in this subterranean tomb. We reveal that Actinobacteria, Pseudonocardiaceae are the dominant organisms on walls in this tomb. These bacteria produce volatile geosmin that attracts springtails (Collembola), forming an interkingdom mutualism, which contributes to their dispersal, as one of the possible sources into the tomb from surrounding environments. Then, intrakingdom competition helps explain why Pseudonocardiaceae thrive in this tomb via the production of a mixture of cellulases, in combination with potential antimicrobial substances. Together, our findings show that multikingdom interactions play an important role in governing the microbiomes that colonize cultural relics. This knowledge is integral to understanding the ecological and physiological features of relic microbiomes and to supporting the relics’ long-term conservation.This work was supported by the National Key R&D Program (2019YFC1520700), the National Natural Science Foundation of China (42177297), Chinese Academy of Sciences (CAS) Strategic Priority Research Program Grant XDA28010302, and the Youth Innovation Promotion Association, CAS (Member No. 2014271). M.D.-B. is supported by a Ramón y Cajal Grant (RYC2018-025483-I), a project from the Spanish Ministry of Science and Innovation (PID2020-115813RA-I00), and Project Plan Andaluz de Investigación, Desarrollo e Innovación 2020 from the Junta de Andalucía (P20_00879).Peer reviewe

Spine surgeon specialty differences in single-level percutaneous kyphoplasty

Background Percutaneous kyphoplasty (PKP) is a procedure performed by a spine surgeon who undergoes either orthopedic or neurosurgical training. The relationship between short-term adverse outcomes and spine specialty is presently unknown. To compare short-term adverse outcomes of single-level PKP when performed by neurosurgeons and orthopedic surgeons in order to develop more concretely preventive strategies for patients under consideration for single-level PKP. Methods We evaluated patients who underwent single-level PKP from 2012 to 2014 through the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP). We used univariate analysis and multivariate logistic regression to assess the association between spine surgeon specialty and short-term adverse events, including postoperative complication and unplanned readmission, and to identify different independent risk predictors between two specialties. Results Of 2248 patients who underwent single-level PKP procedure, 1229 patients (54.7%) had their operations completed by a neurosurgeon. There were no significant differences in the development of the majority of postoperative complications and the occurrence of unplanned readmission between the neurosurgical cohort (NC) and the orthopedic cohort (OC). A difference in the postoperative blood transfusion rate (0.7% NS vs. 1.7% OC, P = 0.039) was noted and may due to the differences in comorbidities between patients. Multivariate regression analysis revealed different independent predictors of postoperative adverse events for the two spine specialties. Conclusions By comparing a large range of demographic feature, preoperative comorbidities, and intraoperative factors, we find that short-term adverse events in single-level PKP patients does not affect by spine surgeon specialty, except that the OC had higher postoperative blood transfusion rate. In addition, the different perioperative predictors of postoperative complications and unplanned readmissions were identified between the two specialties. These findings can lead to better evidence-based patient counseling and provide valuable information for medical evaluation and potentially devise methods to reduce patients’ risk

Characterization of Biochar Derived from Pineapple Peel Waste and Its Application for Sorption of Oxytetracycline from Aqueous Solution

Physicochemical characteristics of biochar and its sorption potential for oxytetracycline (OTC) were investigated. Biochars from pineapple peel waste were produced via pyrolysis under oxygen-depleted conditions at 350 °C (BL350), 500 °C (BL500), and 650 °C (BL650), as well as the characteristics and polycyclic aromatic hydrocarbons contents of the samples were compared. The sorption kinetics of OTC onto the biochars was completed in three stages, i.e., a fast stage, a slow stage, and an equilibrium stage after 24 h. The kinetics data were perfectly fitted by the pseudo-second-order model with high correlation coefficients (R2 > 0.999). All of the sorption isotherms were nonlinear and well described by the Langmuir model. The Langmuir maximum sorption capacity (qmax) increased in the order of BL650 > BL500 > BL350. The thermodynamic parameters revealed that the sorption of OTC onto the biochars was spontaneous and endothermic. Fourier transform infrared spectroscopy (FTIR) of the biochars before and after sorption of OTC confirmed that the H-bonding interaction was the dominant sorption mechanism. The results demonstrated that biochars obtained from inexpensive and renewable materials could be utilized as a highly effective and environmentally friendly adsorbent for removing organic contaminants from wastewater

Ru₂P Nanoparticle Decorated P/N-Doped Carbon Nanofibers on Carbon Cloth as a Robust Hierarchical Electrocatalyst with Platinum-Comparable Activity toward Hydrogen Evolution

It is desirable yet challenging to develop highly active and durable hydrogen evolution reaction (HER) electrocatalysts with Pt-comparable activity for future energy devices. In this work, we report Ru₂P nanoparticle decorated P/N dual-doped carbon nanofibers on carbon cloth (Ru₂P@PNC/CC-900) as a highly efficient and durable hierarchical HER electrocatalyst in both acidic and alkaline media. Electrochemical tests show that this Ru₂P@PNC/CC-900 possesses Pt-comparable HER activity to support 10 mA cm^–2 HER current density at low overpotential of 15 and 50 mV in acidic and alkaline condition, respectively. Density functional theory calculations reveal that coupling Ru₂P nanoparticles with heteroatom-doped carbon fibers leads to enhanced intrinsic HER activity. The integrative hierarchical architecture further endows high surface areas with good mechanical robustness to support abundant catalytically active sites and possesses excellent electrical conductivity and efficient access for mass transportation to facilitate the HER process

Metal-support interaction boosted electrocatalysis of ultrasmall iridium nanoparticles supported on nitrogen doped graphene for highly efficient water electrolysis in acidic and alkaline media

Metal-support interaction boosted electrocatalysis of ultrasmall iridium nanoparticles supported on nitrogen doped graphene for highly efficient water electrolysis in acidic and alkaline medi

Mesoporous Hollow Nitrogen-Doped Carbon Nanospheres with Embedded MnFe₂O₄/Fe Hybrid Nanoparticles as Efficient Bifunctional Oxygen Electrocatalysts in Alkaline Media

Exploring sustainable and efficient electrocatalysts for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is necessary for the development of fuel cells and metal–air batteries. Herein, we report a bimetal Fe/Mn–N–C material composed of spinel MnFe₂O₄/metallic Fe hybrid nanoparticles encapsulated in N-doped mesoporous hollow carbon nanospheres as an excellent bifunctional ORR/OER electrocatalyst in alkaline electrolyte. The Fe/Mn–N–C catalyst is synthesized via pyrolysis of bimetal ion-incorporated polydopamine nanospheres and shows impressive ORR electrocatalytic activity superior to Pt/C and good OER activity close to RuO₂ catalyst in alkaline environment. When tested in Zn–air battery, the Fe/Mn–N–C catalyst demonstrates excellent ultimate performance including power density, durability, and cycling. This work reports the bimetal Fe/Mn–N–C as a highly efficient bifunctional electrocatalyst and may afford useful insights into the design of sustainable transition-metal-based high-performance electrocatalysts

A deep unrolled neural network for real-time MRI-guided brain intervention

<p>The implementation of LSFP-Net.</p&gt