Diamond with nitrogen: states, control, and applications

The burgeoning multi-field applications of diamond concurrently bring up a foremost consideration associated with nitrogen. Ubiquitous nitrogen in both natural and artificial diamond in most cases as disruptive impurity is undesirable for diamond material properties, eg deterioration in electrical performance. However, the feat of this most common element-nitrogen, can change diamond growth evolution, endow diamond fancy colors and even give quantum technology a solid boost. This perspective reviews the understanding and progress of nitrogen in diamond including natural occurring gemstones and their synthetic counterparts formed by high temperature high pressure (HPHT) and chemical vapor deposition (CVD) methods. The review paper covers a variety of topics ranging from the basis of physical state of nitrogen and its related defects as well as the resulting effects in diamond (including nitrogen termination on diamond surface), to precise control of nitrogen incorporation associated with selective post-treatments and finally to the practical utilization. Among the multitudinous potential nitrogen related centers, the nitrogen-vacancy (NV) defects in diamond have attracted particular interest and are still ceaselessly drawing extensive attentions for quantum frontiers advance.</p

Morphology-dependent antibacterial properties of diamond coatings

Microorganisms promoted corrosion has caused significant loss to marine engineering and the antibacterial coatings have served as a solution that has gained attention. In this study, the chemical vapour deposition technique has been employed to grow three different types of diamond coatings, namely, ultrananocrystalline diamond (UNCD), nanocrystalline diamond (NCD), and microcrystalline diamond (MCD) coatings. The evolution of associated surface morphology and the surface functional groups of the grown coatings have demonstrated antibacterial activity in seawater environments. It is found that different ratio of sp3/sp2 carbon bonds on the diamond coatings influences their surface property (hydrophobic/hydrophilic), which changes the anti-adhesion behaviour of diamond coatings against bacteria. This plays a critical role in determining the antibacterial property of the developed coatings. The results show that the diamond coatings arising from the deposition process kill the bacteria via a combination of the mechanical effects and the functional groups on the surface of UNCD, NCD, and MCD coatings, respectively. These antibacterial coatings are effective to both Gram-negative bacteria (E. coli) and Gram-positive bacteria (B. subtilis) for 1–6 h of incubation time. When the contact duration is prolonged to 6 h or over, the MCD coatings begin to reduce the bacteria colonies drastically and enhance the bacteriostatic rate for both E. coli and B. subtilis.</p

Doomed Couple of Diamond with Terahertz Frequency: Hyperfine Quality Discrimination and Complex Dielectric Responses of Diamond in the Terahertz Waveband

The technology age of terahertz (THz) frequency is coming with tremendous features and astonishing applications in various fields of science. Using THz time domain spectroscopy, we demonstrate experimentally, for the first time, the fingerprint absorption peaks and the complex dielectric response trends in 0.1-3 THz frequency waveband, on intentionally synthesized and processed chemical vapour deposition (CVD) polycrystalline and single-crystal diamond films with systematic quality-difference. The two absorption signatures within the 0.1-3 THz frequency band, in which the atomic vibration is materials-independent, are attributed to the sp2 phonon vibration modes of as-grown graphitic phases and/or defects. Regarding the complex dielectric responses of diamond in THz waveband, scattering effect resulting from the extended grain boundaries associated with concomitant pores (even gaps) (and/or extended crystal cleavage faults associated with amorphous carbon), as well as intrinsic lattice absorption resulting from increased sp2 impurities, have been taken into account. Especially the defect size comparable with the wavelength is also found to play a significant effect on the loss at higher-frequency electromagnetic wave. These findings are expected to promote not only ultra-sensitive quality diagnose for diamond but verification of an ideal transmission material for THz waveband applications

Disruptive Strategy To Fabricate Three-Dimensional Ultrawide Interlayer Porous Carbon Framework-Supported Prussian Blue Nanocubes: A Carrier for NiFe-Layered Double-Hydroxide toward Oxygen Evolution

We, for the first time, offer a unique and disruptive strategy to prepare N-doped three-dimensional porous carbon framework-supported well-defined Fe4[Fe(CN)6]3 nanocubes (indicated as PB@N-PCFs). The carbon frameworks hold an ultrawide interlayer spacing of 0.385–0.402 nm for the (002) planes of graphite and ultrahigh graphitization. Furthermore, PB@N-PCFs are used as a carrier to grow NiFe-layered-double-hydroxide nanosheet arrays (denoted as NiFe-LDH/PB@N-PCFs) in situ, where the interlayer spacing for the (002) planes of graphite can be expanded as high as 0.457 nm in the carbon frameworks. Moreover, NiFe-LDH/PB@N-PCFs shows excellent electrocatalytic performance toward oxygen evolution in terms of activity, kinetics, and durability, elegantly rivaling the state-of-the-art RuO2. More profoundly, after 3000 cycle cyclic voltammetry scans, NiFe-LDH/PB@N-PCFs still display far more desirable activity with respect to initial NiFe-LDH/PB@N-PCFs. We believe that the PB@N-PCFs and PB@N-PCFs-based composites with ultrahighly graphitized and large interlayer spacing N-PCFs can find more places in electrochemistry-related applications such as Na/K-ion batteries, electrocatalysis, and electrochemical sensors

Data_Sheet_1_Efficacy and safety of ultrasound-guided serratus anterior plane block for postoperative analgesia in thoracic surgery and breast surgery: A systematic review and meta-analysis of randomized controlled studies.ZIP

ObjectiveSerratus anterior plane block (SAPB) is a new perioperative analgesia for patients undergoing thoracic and breast surgery. The primary purpose of this systematic review and meta-analysis was to investigate whether ultrasound-guided SAPB combined with general anesthesia provides safer and more effective postoperative analgesia than general anesthesia alone or general anesthesia combined with incisional local infiltration anesthesia in patients receiving thoracic and breast surgery.MethodsWe systematically searched PubMed, Embase, Web of Science and the Cochrane Library databases for clinical randomized controlled trials (RCTs) of SAPB for postoperative analgesia in thoracic and breast surgery. The primary outcome was the postoperative pain score. Secondary outcomes included intraoperative opioid consumption, 24-h postoperative opioid consumption, time to first use of analgesics, number of patients requiring urgent additional analgesics, opioid complications (postoperative nausea, vomiting, respiratory depression, constipation, dizziness, sedation) and length of hospital stay. The risk of bias was assessed using the Cochrane method and Jadad score.ResultsA total of 29 RCTs with 1,978 patients were included. Twelve studies included thoracic surgery, and 17 studies included breast surgery. The results of the meta-analysis showed that the rest or movement pain scores of the SAPB group were significantly lower than those of the control group at each postoperative time point. In addition, morphine consumption was significantly reduced in the SAPB group at 24 h postoperatively (standardized mean differences [SMD], −2.77; 95% confidence interval [CI], −3.56 to −1.97; P 2 = 0), dizziness (RR, 0.24; 95% CI, 0.06 to 0.92; P 2 = 0) and sedation (RR, 0.07; 95% CI, 0.01 to 0.52; P 2 = 0) were significantly lower; the length of hospital stay was significantly shorter (SMD, −0.28; 95% CI, −0.46 to −0.09; P ConclusionsCompared with no SAPB block, ultrasound-guided SAPB provides superior postoperative analgesia by reducing postoperative pain scores, the incidence of postoperative pain syndrome at 3 months and perioperative opioid consumption in patients after thoracic and breast surgery. At the same time, SAPB reduces the incidence of side effects of opioids and shortens the length of hospital stay. SAPB can be used as a feasible technique for multimodal analgesia in the perioperative period.</p

Smoothing of single crystal diamond by high-speed three-dimensional dynamic friction polishing: Optimization and surface bonds evolution mechanism

The high-speed three-dimensional movement dynamic friction polishing (3DM-DFP) has been recognized as an efficient approach for ultra-smoothing single crystal diamond (SCD) surface. Continuing from the previous works focusing on the subsurface cleavage of diamond after 3DM-DFP, process optimization and surface reaction evolution mechanism as a fundamental building block is investigated, for the first time, for comprehensively understanding this fast-smoothing manner. By systematically adjusting the controlling factor, stronger load (0.3 MPa) and appropriate duration (0.5 h) as well as moderate sliding speed (in the range of 30 to 45 m s−1) is found to be able to obtain the smooth surface of SCD without uncontacted traces or break-surface cleavage. Subtle residual clues on SCD surface as a function of progressive DFP procedure indicate that Fe catalytic oxidation mainly produce Fe2O3 and partial intermediate oxides Fe1-yO. Meanwhile, the activated oxygen inserts sp3 Csingle bondC bonds could form Csingle bondO or Cdouble bondO and C-O-V (vacancy) at existing reactive surface sites. The (100) favorable Cdouble bondO bonds can be rebuilt if (100) surface is reformed, although the Csingle bondO bonds associated with non-(100) rough surface would replace them during DFP procedure. The formed Csingle bondOsingle bondC and concomitant C-O-V as well as the oxidized graphite give rise to the increase of Csingle bondO proportion, and finally the covered defective graphitic phase has an approximate Csingle bondO/Cdouble bondO ratio of 1.25. All these are endowed potential value for future upgrading of DFP technique for diamond surface smoothing.</div

Evolutionary features of subsurface defects of single crystal diamond after dynamic friction polishing

Due to the fatigue and continuous energy input during high-speed dynamic friction polishing (DFP), the diamond crystal beneath the polished surface (roughness 50 nm) and even preferential crystal cleavage with the non-diamond phase (distributing at the position in micrometers range).</p

Evolutionary features of subsurface defects of single crystal diamond after dynamic friction polishing

Due to the fatigue and continuous energy input during high-speed dynamic friction polishing (DFP), the diamond crystal beneath the polished surface (roughness 50 nm) and even preferential crystal cleavage with the non-diamond phase (distributing at the position in micrometers range).</p

Network pharmacology and <i>in vivo</i> experiment-based strategy to investigate mechanisms of JingFangFuZiLiZhong formula for ulcerative colitis

Ulcerative colitis (UC), a chronic inflammatory disease, often cause carcinogenesis, disability, and intestinal perforation. The JingFangFuZiLiZhong formula (JFFZLZ) shows a good effect against UC in the clinic. Hence, we aim to investigate the mechanisms between JFFZLZ and UC via network pharmacology data mining and in vivo experiments. We obtained active constituents and related targets from public databases. The overlapped genes between JFFZLZ and UC targets were further analysed by enrichment analysis. The active constituents and hub targets were used to construct molecule docking analysis. We finally screened out nine hub targets and their expressions were verified in the Gene Expression Omnibus database and UC rats’ colon tissues after JFFZLZ treatment. The results implied that JFFZLZ mainly regulated signal transduction, metabolites production, and inflammation pathways. The expression of STAT3, CXCL8, IL6, CXCL12, TNF, TP53, and PTPN11 were both upregulated in colon tissues of UC patients and UC rats. While RELA, EGFR, and TP53 were downregulated in UC patients, but upregulated in UC rats. Furthermore, JFFZLZ could repair UC rats’ colon mucosal damage and promote the healing of ulcers via regulating the hub targets. These results elucidated that the anti-UC effect of JFFZLZ was closely related to the inhibition of inflammatory response, inhibition of oxidative stress, and repairing colon mucosal damage through different signal pathways. The findings could contribute to a better understanding of the regulation mechanisms in JFFZLZ against UC.Key messagesJFFZLZ could reduce the inflammatory infiltration and repair UC rats’ colon mucosal damage.Through the network pharmacology-based strategy and public database mining, we obtained the hub targets and key pathways between JFFZLF and UC.The mechanism of JFFZLZ against UC was inhibition of inflammatory response and oxidative stress by regulating the expression of the hub targets. JFFZLZ could reduce the inflammatory infiltration and repair UC rats’ colon mucosal damage. Through the network pharmacology-based strategy and public database mining, we obtained the hub targets and key pathways between JFFZLF and UC. The mechanism of JFFZLZ against UC was inhibition of inflammatory response and oxidative stress by regulating the expression of the hub targets.</p