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Purpose The present study aimed to assess the feasibility, safety and accuracy of navigated spinopelvic fixation with focus on S2-alar-iliac screws (S2AIS) and tricortical S1 pedicle screw implantation with the use of high-resolution three-dimensional intraoperative imaging and real-time spinal navigation. Methods Patients undergoing navigated intraoperative CT-based spinopelvic stabilization between January 2016 and September 2019 were included. Pelvic fixation was achieved by implantation of S2AIS or iliac screws (IS). S1 screws were implanted with the goal of achieving tricortical purchase. In all cases, instrumentation was performed with real-time spinal navigation and intraoperative screw positioning was assessed using intraoperative computed tomography (iCT), cone-beam CT (CBCT) and robotic cone-beam CT (rCBCT). Screw accuracy was evaluated based on radiographic criteria. To identify predictors of complications, univariate analysis was performed. Results Overall, 52 patients (85%) received S2AIS and nine patients (15%) received IS instrumentation. Intraoperative imaging and spinal navigation were performed with iCT in 34 patients, CBCT in 21 patients and rCBCT in six patients. A total number of 10/128 (7.8%) iliac screws underwent successful intraoperative correction due to misalignment. Tricortical purchase was successfully accomplished in 58/110 (53%) of the S1 screws with a clear learning curve in the course of time. S2AIS implantation was associated with significantly fewer surgical side infection-associated surgeries. Conclusions Real-time navigation facilitated spinopelvic instrumentation with increasing accuracy of S2AIS and tricortical S1 screws. Intraoperative imaging by iCT, CBCT or rCBCT permitted screw assessment with the chance of direct navigated revision of misplaced iliac screws to avoid secondary screw revision surgery.

ZusammenfassungDie Instrumentierung des lumbosakralen Überganges mit oder ohne Fusion erfolgt bei einer Vielzahl von Pathologien. Häufig ist dies bei der operativen Therapie von degenerativen Erkrankungen, aber auch bei Frakturen, Infektionen oder tumorassozierten Osteolysen der unteren Lendenwirbelsäule und des Sakrums erforderlich. Die biomechanischen Anforderungen an die Instrumentierung sind in diesem Wirbelsäulenabschnitt besonders hoch. Insbesondere bei langstreckigen Instrumentierungen auf S1 ist eine hohe Pseudarthroserate im Segmet L5/S1 mit und ohne Implantatversagen beschrieben. Um das Risiko von Komplikationen, die zur Schraubenlockerung oder Implantatversagen im Segment L5/S1 führen, zu minimieren, bieten sich mehrere Verfahren an.Revisionsstrategien zur Behandlung dieser Komplikationen erfordern neben der genauen Analyse der Situation, unter Umständen besondere Implantatsysteme und Operations-Techniken. Die Indikationsstellung zum dorsalen, ventralen oder kombinierten Zugang ist im Wesentlichen davon abhängig, ob das Ziel der Operation die Fusion L5/S1 darstellt und wie diese mit größt möglicher Wahrscheinlichkeit erreicht werden kann.

This retrospective matched case-control study was conducted to compare two CT based surgery techniques for navigated screw placement in spinal surgery, whether a reduction of radiation exposure and surgery time could be achieved.We matched cases treated with an intraoperative CT (iCT), regarding the type and number of implants, with cases treated with a preoperative CT (pCT) of one main surgeon. Outcome measures were radiation exposure due to intraoperative control x-rays, radiation exposure due to CT images, and the duration of surgery.The required radiation exposure could be significantly reduced in the iCT group. For the intraoperative control X-rays by 69% (median (MED) 88.50/standard deviation (SD) 107.84 and MED 286.00/SD 485.04 for iCT and pCT respectively-in GycmThe results show that spinal navigation using an intraoperative CT with automatic registration compared to a preoperative CT and intraoperative manual surface registration, allows a significant reduction of radiation exposure, without prolonged surgery time. A significant benefit regarding cut-to-suture-time can be gained with surgeries of a larger scale.

Vinylene-linked two-dimensional covalent organic frameworks (V-2D-COFs) have shown great promise in electronics and optoelectronics. However, only a few reactions for V-2D-COFs have been developed hitherto. Besides the kinetically low reversibility of C=C bond formation, another underlying issue facing the synthesis of V-2D-COFs is the attainment of high (E)-alkene selectivity to ensure the appropriate symmetry of 2D frameworks. Here, we tailor the E/Z selectivity of the Wittig reaction by employing a proper catalyst (i.e., Cs2CO3) to obtain more stable intermediates and elevating the temperature across the reaction barrier. Subsequently, the Wittig reaction is innovatively utilized for the synthesis of four crystalline V-2D-COFs by combining aldehydes and ylides. Importantly, the efficient conjugation and decent crystallinity of the resultant V-2D-COFs are demonstrated by their high charge carrier mobilities over 10 cm2 V−1 s−1, as revealed by non-contact terahertz (THz) spectroscopy.

Electrochemical proton storage plays an essential role in designing next-generation high-rate energy storage technologies, e.g., aqueous batteries. Two-dimensional conjugated covalent organic frameworks (2D c-COFs) are promising electrode materials, but their competitive proton and metal-ion insertion mechanisms remain elusive, and COF-based proton storage is rarely explored. Here, we report a perinone-based ladder-type 2D c-COF towards fast proton storage in both mild aqueous Zn-ion electrolyte and strong acid. We unveil that the generated C-O- groups via discharge exhibit largely reduced basicity due to the considerable pi-delocalization in perinone, thus affording the 2D c-COF a unique affinity to proton with fast kinetics. As a consequence, the 2D c-COF electrode presents outstanding rate capability up to 200 A g-1 (over 2500C). Our work reports the first example of proton storage among COFs and highlights the great potential of perinone-based 2D c-COF in future energy devices.

Angewandte Chemie / International edition e202202492 (2022). doi:10.1002/anie.202202492, Published by Wiley-VCH, Weinheim

Safe placement of posterior cervical-sacral pedicle screws, S2-Ala-iliac screws, iliac screws, transarticular screws C1/2, translaminar screws C2 or cervical lateral mass screws under the guidance of spinal navigation.All posterior spinal instrumentations with screws: instabilities and deformities of rheumatic, traumatic, neoplastic, infectious, iatrogenic or congenital origin; multilevel cervical spinal stenosis with degenerative instability or kyphosis of the affected spinal segment.There are no absolute contraindications for spinal navigation.Cervical spine: Prone position on a gel mattress, rigid head fixation, e.g., with Mayfield tongs; if appropriate, closed reduction under lateral image intensification; thoracic + lumbar spine: prone position on a cushioned frame; midline posterior surgical approach at the level of the segments to be instrumented; if necessary, open reduction; insertion of the cervical/upper thoracic screws under the guidance of spinal navigation; if necessary, posterior decompression; instrumentation longitudinal rods; if fusion is to be obtained, decortication of the posterior bone elements with a high-speed burr and onlay of cancellous bone or bone substitutes.In stable instrumentations, no postoperative immobilization with orthosis is necessary, removal of drains (if used) 2-3 days postoperatively (postop), removal of the sutures 14 days postop, clinical and x‑ray controls 3 and 12 months postop or in case of clinical or neurological deterioration.Numerous studies showed that the use of spinal navigation significantly reduces implant malplacement rates, complications, and revision surgery. Furthermore, intraoperative radiation exposure to the operation team can be reduced by up to 90%.OPERATIONSZIEL: Sichere Platzierung von zervikalen-sakralen Pedikelschrauben, S2-Ala-Ilium-Schrauben, Iliumschrauben, transartikulären Schrauben C1/2, translaminären Schrauben oder zervikalen Massa-lateralis-Schrauben unter Verwendung der spinalen Navigation.Alle dorsalen Instrumentierungen an der Wirbelsäule mit Schrauben: Instabilitäten und Deformitäten degenerativer, rheumatischer, traumatischer, neoplastischer, infektiöser, iatrogener oder kongenitaler Genese; multisegmentale zervikale Spinalkanalstenose mit Instabilität oder Kyphose der betroffenen Segmente.Es gibt keine absoluten Kontraindikationen für die spinale Navigation.Lagerung HWS: Bauchlage auf Gelmatte, rigide Kopffixation, z. B. mit Mayfield-Klemme, wenn indiziert geschlossene Reposition unter BV-Kontrolle, Lagerung BWS/LWS: Bauchlage auf Lagerungsblock; Mittellinienzugang über den Indexsegmenten, wenn indiziert offene Reposition, Platzierung der Schrauben mithilfe der spinalen Navigation, wenn notwendig dorsale Dekompression, Instrumentierung mit Längsträgern ggf. dorsale Fusion nach Dekortizieren der verbliebenen dorsalen knöchernen Strukturen und dorsale Fusion mit Eigenknochen und/oder Knochenersatzstoffen.Bei stabilen Instrumentierungen ist keine postoperative Ruhigstellung mit Orthesen notwendig. Entfernung der Redondrainagen (wenn verwendet) nach 2 bis 3 Tagen, Fadenzug am 14. postoperativen Tag; klinische und radiologische Verlaufskontrollen nach 3 und 12 Monaten oder bei klinischer oder neurologischer Verschlechterung.Viele Studien konnten zeigen, dass der Einsatz der spinalen Navigation zu einer signifikanten Reduktion von Implantatfehllagen, Komplikationen und Revisionsoperationen führt. Die intraoperative Strahlenbelastung des OP-Teams kann um bis zu 90 % reduziert werden.

The interest in two-dimensional conjugated polymers (2D CPs) has increased significantly in recent years. In particular, vinylene-linked 2D CPs with fully in-plane sp2-carbon-conjugated structures, high thermal and chemical stability, have become the focus of attention. Although the Horner-Wadsworth-Emmons (HWE) reaction has been recently demonstrated in synthesizing vinylene-linked 2D CPs, it remains largely unexplored due to the challenge in synthesis. In this work, we reveal the control of crystallinity of 2D CPs during the solvothermal synthesis of 2D-poly(phenylene-quinoxaline-vinylene)s (2D-PPQVs) and 2D-poly(phenylene-vinylene)s through the HWE polycondensation. The employment of fluorinated phosphonates and rigid aldehyde building blocks is demonstrated as crucial factors in enhancing the crystallinity of the obtained 2D CPs. Density functional theory (DFT) calculations reveal the critical role of the fluorinated phosphonate in enhancing the reversibility of the (semi)reversible C−C single bond formation.

The reliability of quartz electron spin resonance (ESR) dating using the Ti centre was tested through a comparison of the ESR ages of loess from the Luochuan site, Chinese loess plateau, with reference ages. Instead of the commonly used multiple-aliquot additive dose (MAAD) protocol, the single-aliquot regenerative dose (SAR) protocol was used to calculate the equivalent dose (De) values of five samples, with expected ages ranging from 28.5 ± 2.9 ka (unit L1) to 646 ± 65 ka (unit L6). The apparent ages, ranging from 59.4 ± 3.8 to 517 ± 42 ka, were then corrected for thermal signal loss, using the lifetime of the Ti centre, ∼1.7 × 106 years, previously calculated for a sample from the same site. The corrected ages ranged from 60.4 ± 3.8 ka to 617 ± 50 ka. For the youngest two samples both apparent and corrected ages overestimated the expected ages, which was presumably caused by incomplete signal resetting before burial. The apparent age of the oldest sample showed an age underestimation of ∼20%, but after the thermal signal loss from the Ti centre was corrected for, the age was consistent with the reference age. Both apparent and corrected ages of L3 and L4 are in good agreement with expected ages. We show, that with careful consideration of the thermal stability and bleachability of samples, reliable age calculation using the Ti centre is possible.

Understanding and controlling isomerization at the single molecular level should provide new insight into the molecular dynamics and design guidelines of functional devices. Scanning tunneling microscopy (STM) has been demonstrated to be a powerful tool to study isomerization of single molecules on a substrate, by either electric field or inelastic electron tunneling mechanisms. A similar molecular isomerization process can in principle be induced by mechanical force; however, relevant study has remained elusive. Here, we demonstrate that isomerization of a N,N-dimethylamino-dianthryl-benzene molecule on Ag(100) can be mechanically driven by the STM tip. The existence of an out-of-plane dimethylamino group in the molecule is found to play a pivotal role in the isomerization process by providing a steric hindrance effect for asymmetric interaction between the STM tip and the molecule. This underlying mechanism is further confirmed by performing molecular dynamics simulations, which show agreement with experimental results. Our work opens the opportunity to manipulate the molecular configuration on the basis of mechanical force.

Objective To validate with a prospective study a decision-supporting coding system for the surgical approach for multilevel degenerative cervical myelopathy. Methods Ten cases were presented on an internet platform, including clinical and imaging data. A single-approach (G1), a choice between 2 (G2), or 3 approaches (G3) were options. Senior and junior spine surgeons analyzed 7 parameters: location and extension of the compression of the spinal cord, C-spine alignment and instability, general morbidity and bone diseases, and K-line and multilevel corpectomy. For each parameter, an anterior, posterior, or combined approach was suggested. The most frequent letter or the last letter (if C) of the resulting 7-letter code (7LC) suggested the surgical approach. Each surgeon performed 2 reads per case within 8 weeks. Results G1: Interrater reliability between junior surgeons improved from the first read (κ = 0.40) to the second (κ = 0.76, p < 0.001) but did not change between senior surgeons (κ = 0.85). The intrarater reliability was similar for junior (κ = 0.78) and senior (κ = 0.71) surgeons. G2: Junior/senior surgeons agreed completely (58%/62%), partially (24%/23%), or did not agree (18%/15%) with the 7LC choice. G3: junior/senior surgeons agreed completely (50%/50%) or partially (50%/50%) with the 7LC choice. Conclusion The 7LC showed good overall reliability. Junior surgeons went through a learning curve and converged to senior surgeons in the second read. The 7LC helps less experienced surgeons to analyze, in a structured manner, the relevant clinical and imaging parameters influencing the choice of the surgical approach, rather than simply pointing out the only correct one.

In this study, we examined the residual doses of the quartz electron spin resonance (ESR) signals from eight young fluvial sediments with known luminescence ages from the Lower Rhine terraces. The single aliquot regenerative (SAR) protocol was applied to obtain the residual doses for both the aluminium (Al) and titanium (Ti) impurity centres. We show that all of the fluvial samples carry a significant amount of residual dose with a mean value of 1270 ± 120 Gy for the Al centre (including the unbleachable signal component), 591 ± 53 Gy for the lithium-compensated Ti centre (Ti-Li), 170 ± 21 Gy for the hydrogen-compensated Ti centre (Ti-H) and 453 ± 42 Gy for the signal that originated from both the Ti-Li and Ti-H centres (termed Ti-mix). To test the accuracy of the ESR SAR protocol, a dose recovery test was conducted and this confirmed the validity of the Ti-Li and Ti-mix signal results. The Al centre shows a dose recovery ratio of 1.75 ± 0.18, whereas the Ti-H signal shows a ratio of 0.55 ± 0.17, suggesting that the rate of signal production per unit dose changed for these signals after the thermal annealing. Nevertheless, all fluvial sediments investigated in this study carry a significant residual dose. Our result suggests that more direct comparisons between luminescence and ESR equivalent doses should be carried out, and, if necessary, the subtraction of residual dose obtained from the difference is essential to obtain reliable ESR ages.

The endospore of Bacillus subtilis is formed intracellularly upon nutrient starvation and is encased by proteinaceous shells. The outermost layer, the crust, is a postulated glycoprotein layer that is composed of six proteins: CotV, W, X, Y, Z and CgeA. Despite some insight into protein interactions and the identification of players in glycosylation, a clear picture of its architecture is still missing. Here, we report a comprehensive mutational analysis that confirms CotZ as the anchor of the crust, while the crust structure is provided by CotV, CotX and CotY. CotY seems to be the major structural component, while CotV and CotX are polar and co-depend on each other and partially on CotW. CotW is independent of other crust proteins, instead depending on outer coat proteins, indicating a role at the interface of crust and coat. CgeA is co-expressed with putative glycosyltransferases (CgeB and CgeD) and implicated in crust glycosylation. In accordance, we provide evidence that CgeB, CgeCDE, SpsA-L, SpsM and SpsNOPQR (formerly YfnHGFED) contribute to the glycosylation state of the spore. The crust polysaccharide layer consists of functionally linked rhamnose- and galactose-related variants and could contain rare sugars. It may therefore protect the crust against biological degradation and scavenging.

Binaphthyl-3,3',4,4'-tetraone was prepared and coupled to different bis(TIPS-ethynyl)-substituted (TIPS=triisopropyl silane) aromatic diamines, resulting in the formation of dimeric benzo-fused azaacenes, centrally connected by a single bond. The two halves of the molecules are highly twisted with respect to each other and showed limited electronic interaction in the ground state because their absorption spectra remained very similar to those of the constituting monomers. The dimers displayed greatly reduced fluorescence when compared to the monomers, suggesting that there is a significant interaction of the two azarene units in the excited state. Preliminary investigations showed that the dimers are attractive for application as acceptors in organic photovoltaic because they significantly outperform their monomeric counterparts.

Polycyclic aromatic azomethine ylides (PAMYs) are powerful building blocks in the bottom-up synthesis of internally nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs) through 1,3-cycloaddition reactions. In this work, the cycloaddition reaction of PAMYs to asymmetric ortho-quinones is presented, which, in contrast to the addition to symmetric para-quinones, facilitates subsequent condensation reactions and allows the synthesis of three helical N-PAHs with ullazine-quinoxaline (UQ-1-3) backbones. UQ-1 and UQ-2 possess two helical centers; however, single-crystal X-ray analysis together with the computational modeling of UQ-3 elucidate the formation of only the thermodynamically most stable geometry with four helical centers in a (P,P,M,M) configuration. For the series UQ-1-3, the number of redox steps is directly correlated with the number of ullazine or quinoxaline units incorporated into the targeted molecular backbones. A detailed investigation of the spectroscopic and magnetic properties of the radical cation and anion as well as the dication and dianion species by in situ EPR/UV/Vis-NIR spectroelectrochemistry is provided. The excellent optical and redox properties combined with helical geometries render them possibly applicable as chiral emitter or ambipolar charge transport material in organic electronics.

The natural electron spin resonance (ESR) dose response curve (DRC) of the Al and Ti centres was constructed for the first time using sand-sized quartz samples from Luochuan, Chinese Loess Plateau. The natural DRC of both centres showed an unexpected early saturation, with characteristic saturation dose (D0) values of ∼760 Gy for the Al centre and ∼650 Gy for the Ti centre, when fitted with a single saturating exponential function. This corresponds to an upper age limit of ∼500 ka (Al centre) and ∼400 ka (Ti centre), using the mean dose rate of 3 Gy/ka. The laboratory DRC of both centres showed much higher saturation dose, but both intensity and D0 value of the regenerated ESR signals decreased significantly with increasing preheat temperatures. The natural DRC had a better match with the laboratory DRC following higher temperature preheats, ∼210–240 °C for 4 min, suggesting the need for preheating after laboratory irradiation for quartz ESR dating. The results of isothermal heating tests revealed that the thermal lifetime at 10 °C at the studied site was ∼1.5 × 109 and ∼1.7 × 106 years for the Al and Ti centres. Although the thermal lifetime of these impurity centres could be sample dependent, the relatively short lifetime of the Ti centre contributed to the early saturation of the natural DRC of the Chinese loess. This highlights the importance of investigating the thermal lifetime of signals for dating older samples using ESR.

OBJECTIVE Fusion is the standard of treatment for degenerative lumbar symptomatic instabilities. Dynamic stabilization is a potential alternative, with the aim of reducing pathological motion. Potential advantages are a reduction of surgical complexity and morbidity. The aim of this study was to assess whether dynamic stabilization is associated with a higher degree of functional improvement while reducing surgical complexity and thereby surgical duration and perioperative complications in comparison with lumbar fusion. METHODS This was a multicenter, double-blind, prospective, randomized, 2-arm superiority trial. Patients with symptomatic mono- or bisegmental lumbar degenerative disease with or without stenosis and instability were randomized 1:1 to instrumented fusion or pedicle-based dynamic stabilization. Patients underwent either rigid internal fixation and interbody fusion or pedicle-based dynamic stabilization. The primary endpoint was the Oswestry Disability Index (ODI) score, and secondary endpoints were pain, health-related quality of life, and patient satisfaction at 24 months. RESULTS Of 293 patients randomized to fusion or dynamic stabilization, 269 were available for analysis. The duration of surgery was significantly shorter for dynamic stabilization versus fusion, and the blood loss was significantly less for dynamic stabilization (380 ml vs 506 ml). Assessment of primary and secondary outcome parameters revealed no significant differences between groups. There were no differences in the incidence of adverse events. CONCLUSIONS Dynamic pedicle-based stabilization can achieve similar clinical outcome as fusion in the treatment of lumbar degenerative instabilities. Secondary failures are not different between groups. However, dynamic stabilization is less complex than fusion and is a feasible alternative.

In this study, we examined the residual doses of the quartz electron spin resonance (ESR) signals from eight young fluvial sediments with known luminescence ages from the lower Rhine terraces. The single aliquot regenerative (SAR) protocol was applied to obtain the residual doses for both the Aluminium (Al) and Titanium (Ti) impurity centres. We show that all of the fluvial samples carry a significant amount of residual dose with a mean value of 1350 ± 120 Gy for the Al centre, 610 ± 60 Gy for the lithium-compensated Ti centre (Ti-Li), 170 ± 20 Gy for the hydrogen-compensated Ti centre (Ti-H), and 470 ± 50 Gy for the signal originated from both the Ti-Li and Ti-H centres (termed Ti-mix). To test the accuracy of the ESR SAR protocol, a dose recovery test was conducted and this confirmed the validity of the Ti-Li and Ti-mix signal results. The Al centre shows a dose recovery ratio of 1.74 ± 0.16, probably due to a sensitivity change by the thermal treatment in the SAR procedure, whereas the Ti-H signal shows a ratio of 0.56 ± 0.17. The results of this study suggest that fluvial sediments carry a significant residual dose, and therefore the subtraction of residual dose using a modern analogue is highly recommended to obtain reliable ESR ages.

Two-dimensional covalent organic frameworks (2D COFs) with covalently bonded repeat units and crystalline, porous framework backbones have attracted immense attention since the first 2D COFs were reported by Yaghi’s group in 2005. The extended single-layer structures of 2D COFs are also generally considered to be the 2D polymers. The precise incorporation of molecular building blocks into ordered frameworks enables the synthesis of novel organic materials with designable and predictable properties for specific applications, such as in optoelectronics, energy storage, and conversion. In particular, the 2D π-conjugated COFs (2D-c-COFs) represent a unique class of 2D conjugated polymers that have 2D molecular-periodic structures with extended in-plane π-conjugations. In the 2D-c-COFs, the conjugated skeletons and π–π stacking interactions can provide the pathways for electron transport, while the porous channel can enable the loading of active sites for catalysis and sensing. Thus far, the synthesis of 2D-c-COFs has been mostly limited to Schiff base chemistry based on the condensation reaction between amine and aldehyde/ketone monomers because the construction of 2D COFs as thermodynamically controlled products generally requires a highly reversible reaction for error-correction processes. However, the high reversibility of imine linkages would conversely endow moderate π-electron delocalization due to the polarized carbon–nitrogen bonds and poor stability against strong acids/bases. To achieve robust and highly conjugated 2D-c-COFs, a series of synthesis strategies have been developed, including a one-step reversible reaction with a bond-forming–bond braking–bond reforming function, a quasi-reversible reaction combing reversible and irreversible processes, and postmodifications converting labile bonds to a robust linkage. Among all of the reported 2D-c-COFs, vinylene-linked (also sp2-carbon-linked) 2D covalent organic frameworks (V-2D-COFs) with high in-plane π-conjugation have attracted increasing interest after we reported the first V-2D-COFs via a Knoevenagel polycondensation in 2016. Although C═C bonds have low reversibility, making the synthesis of V-2D-COFs quite challenging, there have been around 40 V-2D-COFs reported over the past 5 years, which demonstrated the merits of V-2D-COFs combining with unique optoelectronic, redox, and magnetic properties. In this Account, we will summarize the development of V-2D-COFs, covering the important aspects of synthesis methods, design strategies, unique physical properties, and functions. First, the solvothermal synthesis of V-2D-COFs using different reaction methodologies and design principles will be presented, including Knoevenagel polycondensation, other aldol-type polycondensations, and Horner–Wadsworth–Emmons (HWE) polycondensation. Second, we will discuss the optoelectronic and magnetic properties of V-2D-COFs. Finally, the promising applications of V-2D-COF in the fields of sensing, photocatalysis, energy storage, and conversion will be demonstrated, which benefit from their robust vinylene-linked skeleton, full in-plane π-conjugation, and tailorable structures. We anticipate that this Account will provide an intensive understanding of the synthesis of V-2D-COFs and inspire the further development of this emerging class of conjugated organic crystalline materials with unique physicochemical properties and applications across different areas.

Photoelectrochemical (PEC) water reduction, converting solar energy into environmentally friendly hydrogen fuel, requires delicate design and synthesis of semiconductors with appropriate bandgaps, suitable energy levels of the frontier orbitals, and high intrinsic charge mobility. In this work, the synthesis of a novel bithiophene-bridged donor-acceptor-based 2D sp

The vast potential of organic materials for electronic, optoelectronic and spintronic devices entails substantial interest in the fabrication of π-conjugated systems with tailored functionality directly at insulating interfaces. On-surface fabrication of such materials on non-metal surfaces remains to be demonstrated with high yield and selectivity. Here we present the synthesis of polyaromatic chains on metallic substrates, insulating layers, and in the solid state. Scanning probe microscopy shows the formation of azaullazine repeating units on Au(111), Ag(111), and h-BN/Cu(111), stemming from intermolecular homo-coupling via cycloaddition reactions of CN-substituted polycyclic aromatic azomethine ylide (PAMY) intermediates followed by subsequent dehydrogenation. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry demonstrates that the reaction also takes place in the solid state in the absence of any catalyst. Such intermolecular cycloaddition reactions are promising methods for direct synthesis of regioregular polyaromatic polymers on arbitrary insulating surfaces.

The vast potential of organic materials for electronic, optoelectronic and spintronic devices entails substantial interest in the fabrication of π-conjugated systems with tailored functionality directly at insulating interfaces. On-surface fabrication of such materials on non-metal surfaces remains to be demonstrated with high yield and selectivity. Here we present the synthesis of polyaromatic chains on metallic substrates, insulating layers, and in the solid state. Scanning probe microscopy shows the formation of azaullazine repeating units on Au(111), Ag(111), and h-BN/Cu(111), stemming from intermolecular homo-coupling via cycloaddition reactions of CN-substituted polycyclic aromatic azomethine ylide (PAMY) intermediates followed by subsequent dehydrogenation. Matrix-assisted laser desorption/ionization (MALDI) mass spectrometry demonstrates that the reaction also takes place in the solid state in the absence of any catalyst. Such intermolecular cycloaddition reactions are promising methods for direct synthesis of regioregular polyaromatic polymers on arbitrary insulating surfaces., This work was financially supported by the European Research Council Consolidator Grant NanoSurfs (no. 615233), the Advanced Grant (no. 694097), the Horizon 2020 research and innovation program 2D ink (no. 664878) and the National Science Foundation of China (no. 11974403 and Sino-German Project no. 51761135130). W.A. acknowledges funding by the DFG via a Heisenberg professorship. M.R., R.B., and X.F. thank the German Research Foundation (DFG) within the Cluster of Excellence “Center for Advancing Electronics Dresden (cfaed)” and EnhanceNano (No. 391979941). A.P.P. and A.Ru. thank the Cluster of Excellence "Advanced Imaging of Matter (AIM)" and Grupos Consolidados (IT1249-19). M.G. acknowledges funding by the H2020-MSCA-IF−2014 program under GA no. 658070 (2DNano).

In this work, we demonstrate the first synthesis of vinylene‐linked 2D CPs, namely, 2D poly(phenylenequinoxalinevinylene)s 2D‐PPQV1 and 2D‐PPQV2, via the Horner–Wadsworth–Emmons (HWE) reaction of C 2‐symmetric 1,4‐bis(diethylphosphonomethyl)benzene or 4,4′‐bis(diethylphosphonomethyl)biphenyl with C 3‐symmetric 2,3,8,9,14,15‐hexa(4‐formylphenyl)diquinoxalino[2,3‐a:2′,3′‐c]phenazine as monomers. Density functional theory (DFT) simulations unveil the crucial role of the initial reversible C−C single bond formation for the synthesis of crystalline 2D CPs. Powder X‐ray diffraction (PXRD) studies and nitrogen adsorption‐desorption measurements demonstrate the formation of proclaimed crystalline, dual‐pore structures with surface areas of up to 440 m2 g−1. More importantly, the optoelectronic properties of the obtained 2D‐PPQV1 (Eg=2.2 eV) and 2D‐PPQV2 (Eg=2.2 eV) are compared with those of cyano‐vinylene‐linked 2D‐CN‐PPQV1 (Eg=2.4 eV) produced by the Knoevenagel reaction and imine‐linked 2D COF analog (2D‐C=N‐PPQV1, Eg=2.3 eV), unambiguously proving the superior conjugation of the vinylene‐linked 2D CPs using the HWE reaction., 2D CPs via the Horner–Wadsworth–Emmons Reaction: A novel methodology for the solvothermal bottom‐up synthesis of 2D vinylene‐linked conjugated polymers (2D CPs) with a nitrogen‐doped skeleton by linking hexaazatrinaphthalene (HATN) units and phenyl/biphenyl units by vinylene linkages is reported.

Luminescent organic materials with high photostability are essential in optoelectronics, sensor, and photocatalysis applica-tions. However, small organic molecules are generally sensitive to UV irr...

We report on the formation of nitrogen-doped nanographenes containing five- and seven-membered rings by thermally induced cyclodehydrogenation on the Au(111) surface. Using scanning tunneling microscopy and supported by calculations, we investigated the structure of the precursor and targets, as well as of intermediates. Scanning tunneling spectroscopy shows that the electronic properties of the target nanographenes are strongly influenced by the additional formation of non-hexagonal rings.

ZusammenfassungDas akute traumatische Central Cord Syndrom (aTCCS) wurde erstmalig 1887 beschrieben. Es ist der am häufigsten auftretende Typ einer inkompletten zervikalen Rückenmarksschädigung. Die neurologische Ausfallssymptomatik ist gekennzeichnet durch eine größere motorische Beeinträchtigung der oberen Extremitäten im Vergleich zu den unteren Extremitäten. Meist tritt das aTCCS bei älteren Patienten mit einer vorbestehenden zervikalen Spinalstenose im Rahmen eines Hyperextensionstraumas der Halswirbelsäule auf. Es wird die möglichst frühzeitige operative Therapie empfohlen. Eine primäre initiale intensivmedizinische Therapie ist empfohlen.

Equivalent dose determination with electron spin resonance (ESR) involves laboratory irradiation of samples using a calibrated source. In this study, we investigated the response of the quartz ESR signals to irradiations from 50 kV or 200 kV X-ray sources by inter-comparison with 60Co gamma irradiation using seven quartz samples of different origins. For each sample, the equivalent X-ray irradiation time was calculated, which was required to create the same concentration of defects as a known dose of 60Co gamma-ray. The effective dose rate was obtained from the given gamma dose (188 Gy) divided by the equivalent X-ray irradiation time; this is referred to as the ‘X-ray dose rate’ in this study. The X-ray dose rate estimates from different samples were relatively uniform. However, the dose rate calculated from the Al centre was on average ∼10% higher than that of the Ti centre, and more scattered among different samples especially for the low-energy X-ray source. The ratio of the dose rates, obtained from the two centres (Al/Ti) varied significantly between the samples; four sediment samples from Tajikistan, China, Chile and Greece yielded consistent dose rates from both centres for both sources, whereas the remaining three samples from Japan and Taiwan showed a dose rate up to 26% higher from the Al centre compared to the Ti centre. The cause of the higher effective dose rate for the Al centre for these three samples requires further investigations.

A World of Experiences under the Banner of the Elk. On the «Fabrication of Visibility» in the History of Abercrombie & Fitch The article sheds light on the history of the US-American fashion cult label Abercrombie & Fitch. It departs from an episode that dates back to the corporation's early heydays as an outfitter for hunters, fishermen, and outdoor enthusiasts, and then turns to the more recent history of the company as a supplier of exclusive casual apparel mostly catering younger target groups. In doing so, particular attention is given to the sometimes aesthetic, sometimes scandalous, but always attention catching «fabrication of visibility» which used to be typical for Abercrombie & Fitch from its relaunch in the 1990s until its recent decline and which largely contributed to the company's profitable difference.

By the combination of 9a-azaphenalene and a perpendicularly oriented acene, we have synthesized three derivatives of a series of novel, fully-conjugated nitrogen-containing polycyclic aromatic hydrocarbons (PAHs), namely [7,8]naphtho[2′,3′:1,2]indolizino[6,5,4,3-def]phenanthridine, with an acetylene triisopropylsilyl (TIPS), phenyl or benzothiophenyl substituent. Their optoelectronic properties were studied via UV-Vis-NIR absorption, fluorescence spectroscopy and cyclic voltammetry. In addition, in situ spectroelectrochemistry was performed to investigate the optical and magnetic properties of the mono-radical cation and anion by quasi-reversible oxidation and reduction of 11-(tert-butyl)-5,17-bis((triisopropylsilyl)ethynyl)[7,8]naphtho[2′,3′:1,2]indolizino[6,5,4,3-def]phenanthridine (1a). Theoretical modelling confirmed the predominately closed-shell electronic ground state with a weak diradical character depending on the geometry.

Polycyclic aromatic azomethine ylides (PAMYs) are versatile building blocks for the bottom-up construction of unprecedented nitrogen-containing polycyclic aromatic hydrocarbons (N-PAHs). Here, we demonstrate the 1,3-dipolar cycloaddition between PAMY and 1,4-diphenylbut-2-yne-1,4-dione and the subsequent condensation reaction with hydrazine, which led to unique N-PAHs with a phenyl-substituted pyrrolopyridazine core (PP-1 and PP-2). The molecular structures of pristine PP-1 and tert-butyl-substituted PP-2 were verified by NMR spectroscopy and mass spectrometry. Moreover, the structure of PP-2 was unambiguously elucidated by X-ray single crystal analysis. The optoelectronic properties were investigated by solvent-dependent UV-Vis absorption and fluorescence emission spectroscopy as well as cyclic voltammetry. Additionally, density functional theory (DFT) calculations showed that PP-1 and PP-2 exhibit push-pull behavior. Furthermore, in situ EPR/UV-Vis-NIR spectroelectrochemistry allowed the detailed insight into the spectroscopic properties and spin distribution of radical cation species of PP-2.

The cervical spine involvement in rheumatoid arthritis (RA) is still of significant clinical relevance, although the clinical use of biologicals significantly reduced the incidence and severity of cervical destructions in RA.

Nanographenes, namely polycyclic aromatic hydrocarbons (PAHs) with nanoscale dimensions (>1 nm), are atomically precise cutouts from graphene. They represent prime models to enhance the scope of chemical and physical properties of graphene through structural modulation and functionalization. Defined nitrogen doping in nanographenes is particularly attractive due to its potential for increasing the number of π-electrons, with the possibility of introducing localized antiaromatic ring elements. Herein we present azomethine ylide homocoupling as a strategy to afford internally nitrogen-doped, non-planar PAH in solution and planar nanographene on surfaces, with central pyrazine rings. Localized antiaromaticity of the central ring is indicated by optical absorption spectroscopy in conjunction with theoretical calculations. Our strategy opens up methods for chemically tailoring graphene and nanographenes, modified by antiaromatic dopants., Polyaromatic hydrocarbons can be precisely manipulated to yield ever more complex and discrete graphene analogs, such as nanographenes. Here, the authors use azomethine ylide homocoupling to insert an antiaromatic pyrazine ring into the core of a nanographene, and characterize the molecule’s unique electronic character.