Despite the molecular dimensions of 2–4 nm the multinuclear wires show high conductance (up to 10−2 to 10−3G0) at the single-molecule level with small attenuation factors (β) as revealed by STM-break junction measurements. The high performance can be attributed to the efficient energy alignment between the Fermi level of the metal electrodes and the HOMO levels of the multinuclear molecular wires as revealed by DFT–NEGF calculations. Electrochemical and DFT studies reveal that the strong Ru–Ru interaction through the bridging ligands raises the HOMO levels to access the Fermi level, leading to high conductance and small β values.Here, we report multinuclear organometallic molecular wires having diyl-Ru(dppe) 2 repeating units show high conductance with small attenuation factors. The strong Ru–Ru interaction is the key for the long-range carrier transport.Multinuclear organometallic molecular wires having (diethynylthiophene)diyl-Ru(dppe) To realize molecular wires with efficient long-range electron-transport performance, it is essential to minimize the β factor as much as possible. The coherent tunneling process dominates for molecules with small dimensions, while the incoherent hopping process additionally contributes to the conductance of molecules with dimensions greater than ∼3 nm.5–7 The former process often causes a large β factor mainly due to the energy mismatch between the molecules and electrodes.One of the goals of molecular devices is to control carrier transport through molecular junctions.β values such as (1) narrowing the HOMO–LUMO gap,8–10 (2) extending π-conjugated systems ,11,12 and making use of (3) π-stacking interactions13–15 and (4) metal–metal bonded systems . On the other hand, those longer than 2 nm remain to be developed due to the instability of longer derivatives and synthetic difficulty.Thus far, extensive single-molecule conductance studies have unveiled general strategies for organic and inorganic molecular wires with small  systems .16,17 Thβ factor smaller while increasing the molecular dimensions.18,19 Single-molecule conductance studies of multimetallic complexes containing metal fragments as repeating units are scarce20 in contrast to those of self-assembled monolayer systems.21–26 Berke, Stadler, Lörtscher et al. reported the single-molecule conductance of multinuclear molecular wires of a diiron complex (Fe2), which dimerized to form a tetrairon complex (Fe4) during break-junction (BJ) measurements using a scanning tunneling microscope (STM)   top.27 ICn with electron-rich Ru(dppe)2 fragments ethane) end-capped with gold groups, which facilitated covalent linkage with gold electrodes. The molecular wires shorter than 2 nm turned out to be highly conductive .29,30 The synthetic difficulty, however, hampered the elongation of the system and the β value was moderate (0.25 Å−1). To address these issues, we designed a series of mono-, di- and tri-nuclear molecular wires nR (n = 1–3) consisting of diyl-Ru(dppe)2 repeating units (nPy) and gold-terminated complexes (nAu) were prepared. Notably, these molecular wires were accessible within three steps from their known precursors and showed significantly small β values as a result of metal–metal interaction as will be discussed later.Recently, we reported metallapolyyne wires 2Py and 3Py in two steps from the known vinylidene complex [trans-ClRu(dppe)2 scale" fill="currentColor" stroke="none"><path d="M0 440 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z M0 280 l0 -40 320 0 320 0 0 40 0 40 -320 0 -320 0 0 -40z"/></g></svg>CH2)][PF6].31–34 Treatment of the vinylidene complex with H–C PBM data was replaced with SVG by xgml2pxml:<glyph-data id="z.tbd" format="PBM" resolution="300" x-size="17" y-size="11" xml:space="preserve">0000000000000000000000000000000000000000000000000000111111111111111000000000000000000011111111111111100000000000000000001111111111111110000000000000000000000000000000000000000000000000000</glyph-data><svg xmlns="http://www.w3.org/2000/svg" version="1.0" width="23.636364pt" height="16.000000pt" viewBox="0 0 23.636364 16.000000" preserveAspectRatio="xMidYMid meet"><metadata>Created by potrace 1.16, written by Peter Selinger 2001-2019</metadata><g transform="translate scale" fill="currentColor" stroke="none"><path d="M80 600 l0 -40 600 0 600 0 0 40 0 40 -600 0 -600 0 0 -40z M80 440 l0 -40 600 0 600 0 0 40 0 40 -600 0 -600 0 0 -40z M80 280 l0 -40 600 0 600 0 0 40 0 40 -600 0 -600 0 0 -40z"/></g></svg>C–Th–CC–H 4  and trans-(H–CC–Th–CC)2Ru(dppe)25 (for 3Py) followed by Sonogashira coupling reaction with 4-bromopyridine afforded 2Py and 3Py, respectively. On the other hand, gold-terminated complexes 2Au and 3Au with N-heterocyclic carbene auxiliaries were prepared via sequential desilylation and auration of the TMS-protected precursors 2TMS and 3TMS, respectively, which were obtained from trans-ClRu(dppe)2(CCCCTMS) and 4/5.35 We characterized these complexes by conventional spectroscopic methods. Notably, the complexes prepared here were stable under ambient conditions in both solution and solid state. Molecular structures of 2Py, 2TMS, and 3TMS determined by X-ray crystallography are shown in 2Py; N⋯N), 2.3 , and 3.6 nm , and separations of the Ru atoms are around 1.2 nm. While the thiophene parts may come into contact with gold electrodes,36 they are sufficiently protected by the bulky dppe ligands.We prepared multinuclear molecular wires nR using the STM break-junction method (bias voltage: 100 mV).37 Individual traces for 0.25 M tetraglyme solutions of the pyridine-terminated complexes 2Py and 3Py . Single-molecule conductance of 2Py and 3Py was 2.1 (±0.6) and 1.3 (±0.6) × 10−4G0, respectively, as determined by statistical analysis of the linear-scale histograms.We performed single-molecule conductance measurements of the obtained wires  and 3Py  and S11‡m region , indicat2Au and 3Au were subjected to an STM-break junction study –Au(electrode) covalent bonds to 5–10% .35 Nevertheless, in the individual traces, the steps were observed in the 10−2 to 10−3G0 region, and single-molecule conductance of 2Au and 3Au was determined to be 1.0 (±0.3) × 10−2 and 4.2 (±1.2) × 10−3G0, respectively, from the statistical analysis of the linear-scale histograms. The virtually linear relationship between the conductance in the logarithmic scale and the junctions' dimensions suggests the occurrence of the tunneling process for molecular junctions of 1R–3R .38,39 Thus, the β values for 1Py–3Py and 1Au–3Au are determined to be 0.03 and 0.07 Å−1, respectively.Next, molecular wires β values obtained with low bias voltage (<200 mV)  and comparable to or even smaller than those for porphyrin wires Pn (0.04 Å−1)8 and porphyrin tapes PTn (0.06 Å−1).9 Furthermore, the β value for 1R–3R is smaller than those of the related 1,4-diethynylbenzene-bridged wire with Ru(dppe)2 fragments PhRn  ,40 the onAu can be ascribed to the two following factors: (1) the small contact resistance of the covalent C(acetylide)–Au electrode bonds and (2) the performance of the bridging linkers. For the former factor, the absolute conductance of the organometallic wires 1Au–3Au is significantly larger than that for the molecules compared herein due to the small contact resistance brought about by the strong coupling between the acetylide anchors and the gold electrodes as discussed previously by Lörtscher, Venkatesan, Berke, et al.43 For the bridging linkers, when compared with the porphyrin wires Pn with the same pyridine anchor groups,8 the conductance of 1Py–3Py is larger by one order of magnitude. Furthermore, the conductance of 1Py–3Py is comparable to that of the wires with the less resistive thiolate and thioether anchor groups44 such as the porphyrin tapes PTn, polymethine wires PMn,11 and oligo(thiophene) wires Tn.6,45 Thus, wires nAu are superior to the related wires in these two aspects.The excellent performance of G) can be expressed by 46,47e, h, Γ, EF and EMO represent elemental electric charge, the Planck constant, the electronic coupling between the electrodes and the molecule, the Fermi energy level of the electrodes, and the energy levels of the frontier orbitals of the molecule, respectively. Generally, the β value decreases with the increase of the dimensions of the molecular wire because the contribution of the terminal anchor groups in the conduction orbitals decreases as compared to that of the bridging linker.48 In other words, conductance decreases as the molecular wire is lengthened, if EMO stays constant. To suppress the conductance decay, therefore, controlling EMO is essential.According to the approximated Landauer–Büttiker formula, zero bias conductance . Because acetylide anchor groups form stable σ bonds with Au electrodes,50 the on-top σ-attachment to Au35 pyramidal clusters has been adopted as the molecular junction models. Transmission spectra are shown in 29 the metallapolyyne junction Au–1Au–Au shows a unique transmission spectrum with the two peaks closely located above and below the Fermi level (EF) of the electrodes (highlighted with the dashed line). This phenomenon is due to the splitting of the HOMO of the 1Au caused upon molecular junction formation as a result of charge transfer interaction between the Ru center and the electrodes through the acetylide anchor groups.51 In a manner similar to the dppe junction Au–1Au–Au, the truncated dmpe analogues Au–n′Au–Au (n = 1–3) also undergo orbital splitting  of repeating units increases  → 0.41 (n = 2) → 0.63 eV (n = 3)), while the filled conduction orbitals get closer to EF (−0.20 → −0.05 → −0.03 eV) . The pyridine derivatives show similar features , C3 and C4).29 In this case, the energies of the transmission peaks .In this respect, DFT–NEGF calculations were carried out in order to gain insights into the highly conductive nature and small plitting  to genern = 1–3, .52 The o Fig. S19. The emp0.03 eV) . In partEfilled,  are rathnAu, n = 1–3), we carried out electrochemical and DFT studies for the TMS (nTMS) and H analogues (nH), respectively  and tri-nuclear complexes (3TMS), respectively, show successive two and three reversible oxidation waves.54 The large separations  and 300 mV (ΔE2) for the trinuclear complex 3TMS) reveal significant Ru–Ru interaction with large comproportionation constants (KC > 104).32,55 This metal–metal interaction makes the HOMO energies higher than that of the mononuclear wire 1TMS (−5.18 eV) by 0.49 eV (2TMS) and 0.61 eV (3TMS). In contrast, the HOMO energy level of the mononuclear system is slightly lowered, as the acetylene linkers are elongated from C2TMS to C3TMS and C4TMS  = 0.53 eV for 2H and 0.74 eV for 3H) (E(HOMO)DFT level for trans-(H–CC–Th–CC)2Ru(dppe)25 (−4.39 eV) is comparable to that of 1H and much lower than that of 3H (−3.75 eV). Because the HOMO of 5, a substructure of 3H, is highly delocalized over the (CC–Th–CC)2Ru moiety as also observed for 3H (E(HOMODFT) level for 3H are negligible. The HOMOs of 2H and 3H are composed of the π*-orbitals of the ruthenium fragments and the π-orbitals of the diethynylthienylene bridging linkers, and the anti-bonding orbital interaction between them raises the HOMO energy levels  . Furtherd for 3H , the exty levels .41 Thus,2 repeating units, Au–CC–CC–Ru(dppe)2–{CC–Th–CC–Ru(dppe)2}n−1–CC–CC–Au (n = 1–3). Their high single-molecule conductance with small β factors is shown. The DFT–NEGF study reveals that elongation by insertion of the organometallic repeating units causes a shift of the HOMO conduction peaks towards the electrode's Fermi level. The high HOMO energy levels of the multinuclear systems were ascribed to the Ru–Ru interaction as revealed by the CV and DFT study. Further study to unveil the relationship between the metal–metal interaction and single-molecule conductance is ongoing in our laboratory.In summary, we have described the synthesis, and the results of single-molecule conductance measurements, and electrochemical and theoretical study of multinuclear molecular wires and junctions with the diyl-Ru(dppe)There are no conflicts to declare.SC-012-D0SC06613C-s001SC-012-D0SC06613C-s002


Telomerase-negative cells have limited proliferation potential. In these cells, telomeres shorten until they reach a critical length and induce a permanently arrested state. This process called replicative senescence is associated with genomic instability and participates in tissue and organismal ageing. Experimental data using single-cell approaches in the budding yeast model organism show that telomerase-negative cells often experience abnormally long cell cycles, which can be followed by cell cycles of normal duration, before reaching the terminal senescent state. These series of non-terminal cell cycle arrests contribute to the heterogeneity of senescence and likely magnify its genomic instability. Due to their apparent stochastic nature, investigating the dynamics and the molecular origins of these arrests has been difficult. In particular, whether the non-terminal arrests series stem from a mechanism similar to the one that triggers terminal senescence is not known.Here, we provide a mathematical description of sequences of non-terminal arrests to understand how they appear. We take advantage of an experimental data set of cell cycle duration measurements performed in individual telomerase-negative yeast cells that keep track of the number of generations since telomerase inactivation. Using numerical simulations, we show that the occurrence of non-terminal arrests is a generation-dependent process that can be explained by the shortest telomere reaching a probabilistic threshold length. While the onset of senescence is also triggered by telomere shortening, we highlight differences in the laws that describe the number of consecutive arrests in non-terminal arrests compared to senescence arrests, suggesting distinct underlying mechanisms and cellular states.Replicative senescence is a complex process that affects cell divisions earlier than anticipated, as exemplified by the frequent occurrence of non-terminal arrests early after telomerase inactivation. The present work unravels two kinetically and mechanistically distinct generation-dependent processes underlying non-terminal and terminal senescence arrests. We suggest that these two processes are responsible for two consequences of senescence at the population level, the increase of genome instability on the one hand, and the limitation of proliferation capacity on the other hand.The online version contains supplementary material available at 10.1186/s13578-021-00693-3. The enomenon . During enomenon . ImportaSaccharomyces cerevisiae is a unicellular eukaryote that constitutively expresses telomerase, an enzyme that maintains telomere length homeostasis by preferentially elongating the short telomeres [While the general mechanisms of telomere protection, telomere shortening and senescence onset have been studied for decades, the heterogeneity of senescence and its origins have received less attention. To address this aspect, we used the budding yeast model to explore the dynamics of cell divisions at the single-cell level , 6. Saccelomeres . Becauseelomeres , 8–13. Telomeres , 15.Because of the apparent stochastic nature of the early arrests, mathematical analysis and modelling are powerful approaches to describe them, test hypotheses on their nature and propose underlying laws governing their appearance. We previously built a telomere-shortening model that incorporated the asymmetric molecular mechanism of telomere replication , 17. NumHere, we exploit a more exhaustive set of experimental data derived from cell cycle duration measurements in individual yeast cell lineages captured in microfluidic chambers and tracked by time-lapse microscopy from telomerase inactivation to cell death . We mathWe took advantage of a data set we recently published , where tD to define what was considered to be an abnormally long cell cycle. We observed that some of the abnormally long cell cycles, when appearing for the first time, were located at the end of the lineages and were never followed by a cell cycle of normal duration  (0 ≤ p(j) ≤ 1) for an arrest to occur. Let X be the random variable describing the generation at which the first non-terminal arrest occurs. Then, for every positive integer k, we have:We asked whether the first non-terminal arrest could be caused by a stochastic DNA damage event. Following this hypothesis, at each generation p(j) = p constant and X corresponds to Bernoulli trials. The generation of the first arrest would then follow a geometric distribution, of parameter p = 0.0465. However, a χ² goodness-of-fit test rejected this hypothesis , robustly with regards to the threshold D  did not describe the experimental data accurately  increased in a non-linear, possibly exponential, manner. We tested this hypothesis and to ensure that 0 ≤ p(j) ≤ 1 for every j, we chose to fit the data with a logistic function that approximates an exponential growth for small values of j  allowed us to compute the generation of the first non-terminal arrest in simulated lineages. We found a good agreement between the simulation and the experimental data for the probability mass distribution function  reaching a threshold Lmin could fit the data. To do so, we simulated the senescence onsets of individual lineages according to [N is the number of simulations, n is the number of experimental lineages (here n = 115) and for the jth simulation, G represents the ith lineage out of n lineages, ordered from shortest to longest and simulated with the law of telomeric signalling L1 + α L2 = Lmin, and ith shortest lineage in the ordered set of the n experimental lineages.We therefore applied the telomere shortening model to look for a potential length threshold at which the first arrest would be induced. Each lineage started with an initial steady-state telomere length distribution simulated based on the length-dependent regulation of telomerase action. Telomeres were then allowed to shorten at each cell division, taking the asymmetry of telomere replication into account. We used the same approach as in , 17 and rding to , 17 and α that minimized e was always 0, indicating that taking only the length of the shortest telomere into account, and not the second, led to the best fit. We therefore chose α = 0 for the rest of the present work. The Lmin that minimized e was 61 bp, larger than the value 19 bp found in [N = 1000 simulations was represented , whether it signals the first arrest or not. Equation (4) shows that we assume that the probability of signalling senescence increases when L decreases. If a telomere happens to reach a length of 0 bp, which is a physiologically relevant situation [At a molecular level, it would not be surprising that the signalling threshold for the shortest telomere might be probabilistic rather than deterministic (see discussion). To take into account this possibility, we chose ituation , the arrN = 1000), we fitted the parameters a and b on the experimental data and found the best fit to be a = 0.023 and b = 0.276, giving a signalling probability that is small if the shortest telomere is greater than 150 bp (p(150) = 0.009), and takes increasingly larger values as the shortest telomere decreases in length  defining the geometric laws and representing the probability of ending the consecutive arrests were different for the two processes: for example, 0.71 and 0.58 for the non-terminal and terminal senescence arrests, respectively, for D = 240 min. We then measured the difference in duration between non-terminal and senescence arrests and found that for a sequence of non-terminal consecutive arrests, the last long cell cycle had a duration on average similar to the preceding long cell cycles ” as a function of the threshold D . Red line represents p-value = 0.05. The hypothesis is rejected for all D tested. Figure S2. A telomere-shortening model with a deterministic length threshold does not fit the experimental first non-terminal arrest data. Ordered generations of the first non-terminal arrest from the experimental data  or simulations based on the deterministic length threshold model (N = 1000), with the blue shaded area representing the 95% quantile. Figure S3. The overrepresentation of pairs of juxtaposed or closely positioned arrests is not compatible with a random distribution of arrests. Dots represent p-values of χ² goodness-of-fit tests for the distribution shown in Fig. 4A being a geometric distribution as a function of the threshold D. Red line represents p-value = 0.05. The hypothesis is rejected for most D tested.


This work describes a versatile electrospinning equipment with rapid, independent, and precise x–y–z movements for large-area depositions of electrospun fibers, direct writing or assembly of fibers into sub-millimeter and micron-sized patterns, and printing of 3D micro- and nanostructures. Its versatility is demonstrated thought the preparation of multilayered functional nanofibers for wound healing, nanofiber mesh for particle filtration, high-aspect ratio printed lines, and freestanding aligned nanofibers. Indeed, nanofibers serve as architectural elements in cell and tissue scaffolds6 and are a basis for artificial skins and intelligent textiles8. In addition, they are also an efficient delivery system for bioactive molecules in therapeutic applications. This growing interest drives research into their fabrications through self-assembly, phase-separation drawing process, template-assisted synthesis, solvent casting methods, and electrospinning11. Notably, electrospinning produces micro and nanofibers of various materials, morphologies, textures, and porosities13. Its versatility allows natural, synthetic, and composite nanofibers to be electrospun and produced in scalable quantities. Moreover, the assembly of the nanofibers can be guided to create complex 3D objects for various application needs15. Thus, electrospun nanofibers are used in drug delivery, wound dressing, bone regeneration, and tissue engineering research16.Nanomaterials, particularly nanofibers, are the subject of intense studies because of their potential uses in medicine, electronics, and catalysis17 propose a rigorous mathematical approach in predicting jet behavior and the use of a magnetic field to control the electrospinning process. Alternatively, Rebrov et al.18 employed high-voltage pulse generator to deposit aligned fibers, while Coppola et al.19 described a tethered pyro-electrospinning technique for direct printing electrospun fibers. Furthermore, You et al.20 used a positively-charged, sharp-pin electrode to modify and redistribute electric charge on the base plate to control the jet trajectory and nanofiber deposition. Finally, Thomas et al.21 use a 3D-printing platform to demonstrate tri-axial controlled electrospinning. Coaxial, emulsion, and reactive electrospinning processes directly manipulate the fiber morphology and chemistry and extent their applications to natural and inorganic materials23.There are numerous improvements in the design of electrospinning equipment to enhance its performance. Investigating the whipping instability of the Taylor cone during electrospinning, Xu et al.A new electrospinning device was designed to seamlessly transition from large-area, far-field electrospinning to high-precision, near-field fiber printing. It is built to craft and assemble nanofibers into complex objects such as meshes, nets, nano-walls, aligned fibers, and multi-layered, thin films from a variety of materials, including hydroxypropyl methylcellulose (HPMC), polyethylene oxides (PEO), and polyvinyl alcohol (PVA) materials that are commonly used in food, drug, and biomaterial research and applications.A drawing of the electrospinning equipment is presented in Fig. Electrospun fibers can be deposited over a large area to form a fiber mat, as shown in Fig. 25, while PVA is an excellent matrix for storing and releasing drug molecules27. The two HPMC layers are 5.2 μm thick and consist of 110 ± 20 nm nanofibers to provide structural support for the 30.5 mm thick electrospun PVA (200 ± 40) nm. The PVA nanofibers have an area-to-volume ratio of 2 x 107 m-1 and sustain a gradual release of amoxicillin/clavulanic acid with over 94.8% of the stored active components released at the end of the seven days, as shown by Fig. S. aureus and E. faecalis) and Gram-negative bacteria , as shown in Fig. Figure 2O: EtOH from 2.0 to 1.5 and 1.0 to give 400, 250, 100 nm fibers as shown in Fig. 2O: EtOH from 2.0 to 1.5) sharply decreased the fiber diameter by roughly 150 nm from 410 ± 45 nm  through a main board connected to Arduino (Megablock MegaPi) and a PC computer that enable rapid long-distance movements (100 mm/s), precise positioning (± 5 μm), and fine micron-step motions (1.8 ± 0.09°/PHASE and 400 steps/mm) for a seamless large-scale precision electrospinning. The movement can be programmed to deposit, write, or print different patterns of electrospun fibers. The z-movement controlled the distance of the spinneret from the collector and used a set of stepper motor and shaft to give precision movements as small as 5 mm. The interchangeable spinneret assembly was supported by a cantilevered 3D printed arm that also held a light source and a USB camera  for monitoring the electrospinning. The base and the spinneret were connected to a programmable power supply (NanoNC PS355) and calibrated to deliver precise electric field for controlled electrospinning. The spinneret was designed and fabricated in the laboratory and connected to a syringe pump (kdScientific KDS200) that delivers 0.004µL/h to 3520mL/h of electrospinning solutions. The electrospinning equipment was housed in a transparent chamber equipped with a set of DC fan and humidifier/dehumidifier units to maintain the temperature and humidity during electrospinning. The chamber is connected to a local exhaust to vent solvents. Detailed description of the electrospinning equipment and operation is available in Supplementary Information. The base collector was mounted on a motion platform with independently Hydroxypropyl methylcellulose , polyvinyl alcohol , and poly(ethylene oxide)  were acquired from Sigma-Aldrich and were used as received. Ethanol  and distilled deionized (DDI) water were used as solvent. Table The electrospun samples were inspected under an Olympus BH2-MJLT optical microscope prior to sample preparation for scanning electron microscopy. Samples from electrospun fiber mat were cut by sharp pair of scissors and mounted on aluminum specimen stub by a conducting carbon adhesive tape. A light sputter coating of gold in K575xd sputtering equipment prevents sample charging. The written and printed fibers were also mounted, and sputter coated with an additional precaution of using conductive adhesives to ground the sample surface. The samples were observed under JSM-6700F and JSM-7100F at 10 kV The images were analyzed, and the diameter of the nanofibers were measured by Image J and processed using IBM SPSS Statistics 23 software.S. aureus, E. faecalis, and E. coli to the HPMC/PVA/HPMC with 10 wt.% amoxicillin and clavulanic acid and control PVA sample. The 1 cm diameter test samples were obtained by biopsy punch and placed in the middle of the Mueller- Hinton agar petri dish seeded with a 108 CFU/ml bacterial suspension (0.5 McFarland Standard). The inhibition zones were measured after incubating at 37°C for 48 h. Five weeks old C57BL/6J mice were individually caged and fed with sterile rodent chow. A cocktail of ketamine/xylene (80-100mg/Kg and 10-12.5 mg/kg) was injected as anaesthesia and a sterile biopsy punch was used to create a round-shaped wound. The wound was dressed with PVA (control) or HPMC/PVA/HPMC with 10 wt.% amoxicillin and clavulanic acid (treatment). Painkiller (ketoprofen 100mg/mL) was added to the drinking water to relieve pain in animals the day after the procedure. The wound of each mouse was photographed and measured at day 0, 3, 7 and 14 of the procedure.The HPMC/PVA/HPMC with 10 wt.% amoxicillin and clavulanic acid was investigated for drug release, bactericidal, and wound healing. The release of active ingredient was measured on 30 mg sample in 30 mL PBS solution at 37 °C over 7 days. Aliquots were taken at fixed time intervals and analyzed by Agilent UV Vis spectrophotometer and the released Amoxicillin/Clavulanic Acid were quantified against standard calibration. MTT assay was used to measure the cell viability, proliferation, and cytotoxicity of the sample on A431 human epidermoid carcinoma epithelial cells. Kirby-Bauer disc diffusion determined the Supplementary Information.


Neisseria gonorrhoeae in Nunavut, Canada, using remnant gonorrhea nucleic acid amplification test–positive urine specimens. This study confirms the feasibility of conducting N. gonorrhoeae AMR surveillance and highlights the diversity of gonococcal sequence types and geographic variation of AMR patterns in the territory. We assessed antimicrobial resistance (AMR) in  Neisseria gonorrhoeae reported in the territory of Nunavut, Canada, 837.6 cases/100,000 residents, was 15 times the national rate in Canada  . The National Microbiology Laboratory  has addressed this issue by developing molecular assays to predict AMR and molecular STs from remnant NAAT specimens. We sought to assess the prevalence and distribution of AMR N. gonorrhoeae STs in Nunavut using NAAT-tested N. gonorrhoeae–positive specimens. The Gonococcal Antimicrobial Surveillance Program of Canada is a culture-based laboratory surveillance system monitoring antimicrobial resistance (AMR) trends and gonococcal sequence types (STs) in 2 the largest territory in Canada, is divided into 3 regions: Qikiqtaaluk  in the east, Kivalliq in the center, and Kitikmeot in the west. Nunavut’s reported 2016 population was 35,994  and from the Qikiqtaaluk and Kivalliq regions to the Qikiqtani General Hospital Laboratory  to the National Microbiology Laboratory for molecular antimicrobial susceptibility prediction using NAATs and N. gonorrhoeae multiantigen sequence typing (NG-MAST). Urine specimens submitted to DynaLife laboratories were tested using the Gen-Probe Aptima Combo 2 test . Testing at the Qikiqtani General Hospital Laboratory was done using the Roche-Cobas test . We did not submit repeat samples or test-of-cure specimens. Ethics approval was obtained from the University of Alberta’s Health Research Ethics Board and the Nunavut Research Institute. For this study we used remnant ponA, mtrR delA, porB, penA A311V, penA A501, penA N513Y, and penA G545S), ciprofloxacin-resistance mutations (gyrA and parC), and azithromycin-resistance mutations  to predict antimicrobial susceptibility. We performed DNA extraction, preparation, real-time PCR, and results analysis as described elsewhere  from Nunavut collected between January 1, 2018–December 31, 2019, were included in the study , ciprofloxacin (541 samples), and azithromycin (435 samples). We predicted AMR for an additional 289 cephalosporin results, 436 ciprofloxacin results, and 533 azithromycin results on the basis of expected results of prevalent STs tested . Within N. gonorrhoeae AMR and delineating transmission patterns (N. gonorrhoeae and suggesting the introduction of multiple strains into the territory. Our analysis of routinely collected diagnostic specimens for gonorrhea from Nunavut highlights the usefulness of SNP assays and NG-MAST typing in identifying population-level The first limitation of our study was that no gonococcal cultures were available and cases were compared to national gonococcal cultures, which may not be representative of gonorrhea in all regions. In addition, only urine specimens were collected for gonorrhea in Nunavut. Previous research has highlighted the variability in ST from extragenital sites (N. gonorrhoeae AMR using remnant N. gonorrhoeae–positive NAAT specimens Data based on these findings can be used to provide Nunavut with up-to-date information about the best choices to treat gonorrhea. Because research across Inuit Nunangat has historically often been done in an exploitative way that has not respected Inuit self-determination, meaningful partnerships are required to prioritize research activities and develop approaches that add value for and are accepted by communities. Our findings highlight the feasibility of conducting molecular surveillance for


Despite attracting considerable recent attention, most such fluids have not been applied at a large- scale due to their high costs and/or complex synthesis processes. Here, we report the development of CO2-switchable viscoelastic fluids using commercially available sodium polyacrylate (NaPAA) and N,N-dimethyl ethanol amine (DMEA)-based switchable water. Upon bubbling CO2, into the solutions under study, DMEA molecules are protonated to generate quaternary ammonium salts, resulting in pronounced decreases in solutions viscosity and elasticity due to the influence of increased ionic strength on NaPAA molecular conformations. Upon removal of CO2 via introduction of N2, quaternary salts are deprotonated to tertiary amines, allowing recovery of fluid viscosity and elasticity to near the initial state. This work provides a simple approach to fabricating CO2-switchable viscoelastic fluids, widening the potential use of CO2 in stimuli-responsive applications.Upon stimulus by CO The change in pH that occurred after sparging with CO2 indicates that δ increased to ~56.30 mol%, and thus ~56.24 mol% carboxylate groups were more protonated in the presence of CO2. These results coincide with results of the rheology experiments: viscosities η and relaxation times τR of the 0.65 wt% aqueous solutions dropped sharply after bubbling CO2, revealing that protonation of carboxylate side groups reduced the charge density and corresponding electrostatic repulsions between NaPAA chains to allow a smaller average molecular size than in the initial state. After bubbling N2, the pH of 0.65 wt% NaPAA aqueous solution recovered to 7.99, signifying deprotonation of the carboxylate groups. The pH was not totally restored to its initial value, indicating that 0.86 mol% carboxylate groups were still protonated. This phenomenon also coincides with the prior rheological results, in which the viscosities η and relaxation times τR of NaPAA aqueous solutions were not fully restored to their initial values.Upon bubbling COCDMEA, regardless of the presence of CO2 , the initial δ of DMEA can be calculated at ~2.56 mol%, followed by an increase to ~99.85 mol% after the introduction of CO2, indicating that the tertiary amino groups on DMEA molecules were almost completely protonated. After bubbling N2, the pH of the solution did not recover to its initial value; rather, 80.65 mol% of the tertiary groups were still protonated, which was caused by the larger the basicity, the poorer the “switch” capability [δ for NaPAA of 6.17 × 10−4 mol% was increased to 13.15 mol% after bubbling CO2, then again restored to 9.76 × 10−2 mol%. Thus, one can find that even if CO2 is not available, there was at least some small amount of protonated DMEA in the solution. These results properly clarify why viscoelasticity of the NaPAA solutions containing DMEA evidently decreased before bubbling CO2. By contrast, in the presence of CO2, a large number of protonated DMEA increased the charge density of the fluids, together with protonated carboxylate groups reduced the charge density and electrostatic repulsions between molecular chains, then the synergy of the two effects diminished the size of NaPAA molecules, resulting in the decrease of η and τR with the addition of DMEA. The change in pH of 1.30 wt% NaPAA solution with different DMEA concentrations demonstrated similar tendencies, as shown in The pH of 0.65 wt% NaPAA solutions containing different DMEA concentrations was also examined a. It cane of CO2 . As an ete salts  [39,40,4pability . Besides2 at 25 °C. The conductivity of the 0.65 wt% NaPAA aqueous solution was initially 2.06 mS·cm−1, then increased to 3.53 mS·cm−1 upon CO2 treatment, suggesting that various inorganic ions  were produced. After bubbling N2 to remove CO2, the conductivity of the 0.65 wt% aqueous solution returned to 2.54 mS·cm−1, which was very close to its initial value. Hence, the enhancement of ionic strength weakened electrostatic repulsions between inter- and intramolecular chains, resulting in the observed drop in η and τR.As a typical polyelectrolyte, the conformation of NaPAA molecule chains is usually affected by salts in solutions, which influences the rheological properties of the fluids. To verify the changes in charge density in the NaPAA/DMEA solution at different states, +, further increased the ionic strength of the fluids. Data shown in 2, the maximum conductivity of 0.65 wt% NaPAA solution increased with the addition of DMEA, implying that DMEAH+ was generated in those fluids. The charged DMEAH+ molecules shielded static repulsions among carboxylate groups (–COO−) of the NaPAA molecules, allowing the polymer chains to become coiled and thus reducing electrostatic repulsions between them. Thus, in the presence of CO2, the η and τR of 0.65 wt% NaPAA solution decreased with the increment of DMEA. After introducing N2, the conductivity of the fluids partially returned to their initial values, as exhibited in η and τR could not completely go back to their initial values when introducing N2 to remove CO2. Three repeated cycles indicated that DMEA possesses good CO2-induced switching behavior. In addition, the data in Besides, the protonated DMEA, i.e., DMEAH2-switchable rheological behavior of NaPAA solutions, with or without the addition of DMEA, can be summarized in 2 leads to –COO− in side chains will be protonated to carboxylic acid (–COOH), resulting in a decrease in charge density on the molecular chains relative to that of the initial solution state, as shown in − groups are weakened, and the viscoelasticity of the NaPAA aqueous solution decreases accordingly. Treatment with N2 allows viscoelasticity of the solution to partially recover, due to the partial deprotonation of –COOH groups. On the other hand, for NaPAA solutions that contain DMEA, in addition to the influence of protonation of –COO−, the protonated DMEA plays a crucial role in determining the viscoelasticity of the solution upon the addition of CO2, as displayed in 2 is bubbled into the solutions, the DMEA molecules are protonated to generate quaternary ammonium salts, which shield charges remaining on the NaPAA chains, allowing them to coil more tightly, resulting in a sharp decrease in viscoelasticity of the fluids. Upon removal of CO2, the quaternary salts are deprotonated, causing partial recovery of the viscosity and elasticity of the solutions.Consequently, the mechanism for COMW = 4 × 106–5 × 106 g·mol−1) and DMEA (≥99%) were purchased from Sigma-Aldrich and used as received. CO2 (≥99.998%) and N2 (≥99.998%) were supplied by Xuyuan Chemical Industry Co., Ltd.  and used without further treatment. Ultrapure water with resistivity of 18.25 MΩ cm−1 was produced by an ultrapure water purification system  and used throughout this study.NaPAA  equipped with concentric cylinder geometry (CC27). All measurements were carried out in stress-controlled mode at 25 °C, and Cannon standard oil was used to calibrate the instrument before experimentation. All samples were centrifuged to eliminate the interior bubbles prior to measurements, then equilibrated at 25 °C for at least 10 min prior to experimentation. Dynamic frequency spectra were conducted in the linear viscoelastic region, as determined from dynamic stress sweep measurements.KaH (pKa of the protonated species) values of DMEA and NaPAA were determined by titrating 20 mL of 0.1 M aqueous solutions with 0.1 M hydrochloric acid. The pH was continuously monitored at 25 °C with a S2-T Kit pH-meter  calibrated with standard buffer solution. The pKaH values were obtained by taking the pH readings at the mid-point between two pH jumps.The p2 or N2 alternatively.The conductivity of NaPAA-DMEA solution was recorded with a S230-K conductometer  at 25 °C while bubbling CO2. The effects of NaPAA and DMEA concentrations on measured solution properties were examined to elucidate the mechanism of CO2-responsive tunable rheological properties. It was found that NaPAA showed strong thickening power in pure water. The introduction/removal of CO2 imparted tunable viscoelasticity to the bulk solution, attributed to protonation/deprotonation of carboxylate groups and corresponding reduction/increase in charge density among molecular chains, allowing for reduction/increase in the size of solvated molecular chains. Moreover, the addition of DMEA gave rise to further reductions in viscoelasticity upon bubbling CO2, but initial values could be restored to some extent via N2 treatment. Besides, higher concentrations of DMEA corresponded to greater losses in viscoelasticity. The CO2-responsive switching behavior of DMEA-containing solutions was attributed to protonation of DMEA, which enabled NaPAA molecules to coil up more tightly, thus lowering the viscoelasticity, and to deprotonation of DMEAH+ via bubbling N2, which enabled partial recuperation of the viscoelasticity. This work not only widens the utilization of CO2 in preparing smart viscoelastic fluids but also demonstrates fabrication of such systems using a low-cost, industrial polymer and stimuli-responsive additives.In summary, the rheological properties of NaPAA aqueous solutions with different DMEA concentrations were investigated in the presence and absence of CO


To date, stabilizing crop production by identifying valuable traits for novel cultivars adapted to adverse environments is topical in crop science. Thus, this study will examine how FSPMs are able to address new challenges in crop science for sustainable crop production. FSPMs developed to simulate organogenesis, morphogenesis, and physiological activities under various environments and are amenable to downscale to the tissue, cellular, and molecular level or upscale to the whole plant and ecological level. In a modeling framework with independent and interactive modules, advanced algorithms provide morphophysiological details at various scales. FSPMs are shown to be able to: (i) provide crop ideotypes efficiently for optimizing the resource distribution and use for greater productivity and less disease risk, (ii) guide molecular design breeding via linking molecular basis to plant phenotypes as well as enrich crop models with an additional architectural dimension to assist breeding, and (iii) interact with plant phenotyping for molecular breeding in embracing three-dimensional (3D) architectural traits. This study illustrates that FSPMs have great prospects in speeding up precision breeding for specific environments due to the capacity for guiding and integrating ideotypes, phenotyping, molecular design, and linking molecular basis to target phenotypes. Consequently, the promising great applications of FSPMs in crop science will, in turn, accelerate their evolution and  Global human population is growing rapidly and has been estimated to reach nearly 10 billion by 2050. However, overall crop production at current rate is insufficient for such great population . The concept and definition of FSPMs have been clearly described in many places .The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article, or claim that may be made by its manufacturer, is not guaranteed or endorsed by the publisher.


Kaposi sarcoma (KS) is a form of cancer that primarily appears on the skin but can potentially involve internal organs. There are several types of KS. The purpose of this article is to discuss the manifestations of KS and their appearance on imaging, the differential diagnoses associated with these findings, and molecular markers associated with KS that can aid appropriate diagnosis and therapy. Kaposi sarcoma (KS) is a rare angioproliferative malignancy derived from the endothelium discovered by Hungarian dermatologist Moritz Kaposi in the late 1800s . Human hIn resource-poor areas, diagnosis is often made upon observing the skin lesions, but this has specificity of approximately 80%. Biopsy, including image-guided may be performed to obtain a tissue diagnosis. Histologically, KS is seen as spindle-shaped cells interspersed with abnormal vascular channels . BecauseThe various types of KS include classic KS, endemic KS, epidemic KS, and iatrogenic immunosuppressed KS . The epiKS variants are differentiated primarily by clinical presentation and a radiologist suggesting a potential variant may influence management. The type of variant can affect treatment approach; for example, in addition to other treatments, epidemic KS treatment can include HAART therapy and iatrogenic KS treatment can include reducing immunosuppression or altering the immunosuppressive agent.The classic variant of KS occurs primarily in older men, typically of Jewish descent, in the Mediterranean and Eastern Europe . It can The staging of classic KS is divided into four categories: In stage one, patients typically have nodules on their legs. In stage two, the lesions take on a plaque morphology primarily affecting large areas of the legs and are locally aggressive, defined as spreading quickly , 15. StaThe endemic KS (African KS) variant is most commonly found in Eastern and Central Africa . Four tyA pediatric-specific staging classification has been proposed, known as the Lilongwe pediatric KS staging classification. Stage 1 includes those with mild KS, who show lesions on the skin and mouth. Patients classified with Stage 2 present with lymphadenopathic KS that tends to involve lymph node may present with the facial edema, nodular lesions in the mouth, or several lesions across the body among other signs. In Stage 3, known as Woody Edema KS, patients are separated into either 3A (edema < 10% of the body) or 3B (edema > 10% of the body). In Stage 4, patients have visceral or disseminated skin KS .The epidemic KS variant, also called HIV-related KS, is most commonly diagnosed in patients who test positive for HIV. Incidence of KS in the setting of HIV is related to the degree of immunosuppression, for example, KS incidence is 384.3 per 100,000 person-years with CD4 count > 200 cells/μL at baseline versus 2050.3 with CD4 count < 200 cells/μL . The effMycobacterium avium complex. Generally, these other conditions are characterized by the appearance of lesions in lymph nodes . Ot. Ot24]. Hepatic KS is most commonly seen among patients with AIDS, with about 34% of cases diagnosed during autopsy ; howeverHepatic KS appears differently on various imaging modalities . A nonspAmong untreated AIDS patients, forty to fifty-one percent have visceral involvement of KS, with the gastrointestinal (GI) tract being the most common site . AIDS-reOn CT imaging, diffuse or focal wall thickening Fig.  may be sIn men, within the genitourinary tract, KS is more commonly seen on the penis. In women, genital tract involvement is not commonly seen . LesionsKS of the skin can appear virtually on any part of the body such as arms, legs, face, and neck and is normally present in all variants, especially in AIDS-related KS. There is a propensity for involvement of the lower extremities Figs. , 6 and s18F-FDG-PET/CT scans can be useful in detecting KS, determining the extent of disease, and assessing which lesions are responding to treatment. On these scans, lesions present with low to moderately increased uptake 18F-FDG-PMolecular markers help distinguish KS from other diseases. Histologically, HHV8 expresses LANA-1, and its presence in KS cells indicates the presence of the virus. In addition, expression of viral interleukin-6 (vIL-6) by HHV8 has been associated with progression of KS. LANA-1 is present in more than 90% of patients with KS . For claThe incidence of KS increased with the start of HIV infections in humans and the AIDS epidemic. Antiretroviral drugs to treat HIV were discovered starting in the late 1980s and eventually led to the combination HAART treatment. In 1987, azidothymidine (AZT) was made available to the public, and in 1991, nucleoside reverse transcriptase inhibitors were introduced . In 1995KS is no longer as prevalent as it once was due to the successful introduction of HAART for AIDS. However, it is still found in such patients and in other KS variants such as in iatrogenic immunosuppressed patients, for example related to organ transplants, as well as in classic and endemic forms. It can present with a myriad of manifestations reflected upon imaging of the abdomen and pelvis in addition to other parts of the body. Imaging using modalities such as CT, MRI, and PET/CT scans can aid in diagnosing, staging, and follow-up of KS.


Parkinson’s Disease (PD) is characterized by primary and secondary plasticity that occurs in response to progressive degeneration and long-term L-DOPA treatment. Some of this plasticity contributes to the detrimental side effects associated with chronic L-DOPA treatment, namely L-DOPA-induced dyskinesia (LID). The dopamine D3 receptor (D3R) has emerged as a promising target in LID management as it is upregulated in LID. This upregulation occurs primarily in the D1-receptor-bearing (D1R) cells of the striatum, which have been repeatedly implicated in LID manifestation. D3R undergoes dynamic changes both in PD and in LID, making it difficult to delineate D3R’s specific contributions, but recent genetic and pharmacologic tools have helped to clarify its role in LID. The following review will discuss these changes, recent advances to better clarify D3R in both PD and LID and potential steps for translating these findings. Parkinson’s Disease (PD) is the second-most-common neurodegenerative disorder and is primarily characterized by the death of midbrain dopaminergic neurons in the substantia nigra pars compacta. The loss of dopaminergic inputs to the striatum results in the manifestation of PD’s cardinal motor symptoms: bradykinesia, akinesia, postural instability and rigidity . HoweverOver 60 years ago, L-DOPA was discovered as an effective treatment to replenish the loss of endogenous dopamine . AlthougThe dopamine D3 receptor (D3R) was first molecularly cloned and characterized in 1990 ,8. SinceNotably, D3R possesses the highest affinity for dopamine and potently interacts with many putative D2R-like agonists . TherefoParkinson’s Disease (PD) is characterized by the progressive and irreversible loss of midbrain dopaminergic cells. The striatum normally receives dense dopaminergic input from these cells and undergoes significant changes to compensate for the loss of dopamine. Changes to dopamine receptor expression, largely on medium spiny neurons (MSNs), are one way in which this compensation manifests. This is clearly evident in D1R subcellular localization and function. D1R shares 75–80% transmembrane domain homology with the other D1-like receptor, D5R . Howeverolf, particularly in the rodent striatum. In response to 6-OHDA lesion, Gαolf expression is increased in the striatum, as is DA-dependent AC activity  Raclopride demonstrated an increase in D2-like receptors in early PD within the putamen [As mentioned, D3R expression in the rodent is considerably more restricted than expression of D1R and D2R. Interestingly, despite the fact that the ventral striatum is less affected in PD modeling, D3R mRNA and binding is reduced in the nucleus accumbens following a 6-OHDA lesion in rats or MPTP treatment in monkeys . In tand putamen . In cont putamen . In huma putamen .Although overt changes to D3R expression in PD are still not completely clear, parameters related to D3R signaling do change in response to dopamine cell loss . Followi2+. When calcium/calmodulin-dependent protein kinase II (CaMKII) is activated by Ca2+, CaMKII phosphorylates the third intracellular loop of D3R. In this phosphorylated state, D3R is no longer able to potentiate D1R signaling [D3R changes in response to denervation have also been reported downstream from the striatum in striatonigral terminals . In the ignaling ,43. Howeignaling . Regardlignaling . CollectDopamine replacement therapy with L-DOPA remains the gold-standard pharmacotherapy to mitigate the symptoms of PD. However, with chronic use, LID develops in the majority of patients. Previous plasticity of dopamine receptors, such as the increased synaptic localization of D1R or supersensitization of D3R, that helped to compensate for dopamine loss likely contributes to LID manifestation. In the striatum, D3R changes both in expression and function. As early as 1997, Bordet and colleagues noted that the ectopic expression of D3R in the striatum occurs as a result of L-DOPA administration and actively participates in behavioral sensitization . Since tD3R normally displays low expression in the dorsal striatum, which makes upregulation of D3R notable in and of itself. Blocking D3R upregulation via intrastriatal infusion of oligonucleotide antisense to dopamine D3R mRNA attenuated the development of LID in the 6-OHDA rodent model . Though The mechanism of D3R upregulation is not fully understood. However, D3R expression can be bidirectionally modified with D1R agonism/antagonism, suggesting a role of D1R stimulation in recruitment of D3R ,47. In sBy itself, D3R can signal both G-protein-dependently and independently. In MPTP-treated mice rendered dyskinetic, a low dose of a D3R agonist  results in blunted MAPK signaling . In contIn the striatum, a different pattern emerges in LID between D1R and D3R. This relationship is cooperative, rather than antagonistic. D3R antagonism during L-DOPA treatment in heterozygous D1± reduces direct-pathway markers associated with cellular activation, suggesting a cooperative, rather than antagonistic, interaction between the two receptors in terms of signaling . In in vGiven the abundance of data suggesting a dyskinesiogenic role of D3R, it is not surprising that this has emerged as an intriguing pharmacological target to manage LID . Given tHowever, some D3R antagonists are more promising in ameliorating LID, even if the mechanisms by which they convey their effects remain elusive. Administration of the D3R antagonist PG01037 both before and after L-DOPA administration significantly reduced LID expression in dyskinetic rats, with the 15 min post-L-DOPA regimen being the most effective . PD1037 Clearly, D3R-targeting compounds are highly variable . There aSince its discovery in 1990, D3R has been implicated as a key player in many disorders characterized by dopamine dysfunction ,8. Indee


Molecular machines are often regarded as molecular artworks and sometimes as fancy molecular toys. However, many researchers strive to operate molecular machines as useful tools for realistic practical applications. In this perspective article, shifting the working environment of molecular machines from solution to interfacial media is discussed from the viewpoint of their evolution from scientific toys to useful tools. Following a short description of traditional research into molecular machines in solution and their nanotechnological manipulation on clean solid surfaces, pioneering research into molecular machine operation at dynamic interfaces, such as liquid surfaces, is discussed, along with cutting-edge research into molecular machine functions in living cells and their models. Biomolecular machines within organisms are the products of evolution over billions of years. We may nanoarchitect such sophisticated functional systems with artificial molecular machines within much shorter periods. Molecular machines can be made more useful with interfacial nanoarchitectonics. In addition to improving the intrinsic properties of materials themselves, precise structural control of material components and their organization is an undoubtedly important factor for optimizing their function.13–16 Ideal functional systems can be seen in biological systems, in which highly complex functions are commonly found, as exemplified by photosynthetic processes and signal transduction pathways.17,18 Functional molecules such as proteins and nucleic acids co-operatively work like machines and devices. Learning from these biological examples, molecular machines and molecular devices could also be key players in achieving highly sophisticated materials to meet our societal demands.For various issues facing society, including energy,19 Sir J. Fraser Stoddart20 and Bernard L. Feringa.21 In addition to the work of these awardees, excellent examples of molecules with machine-like functions have been continuously reported.22–31 Some of these molecules can be regarded as molecular artworks and sometimes as fancy molecular toys. However, many researchers have dreams to operate molecular machines as useful tools in realistic practical applications, although it is not an easy process. High-level control of molecular machines and their sophisticated organization would be required to accomplish this dream.The importance of molecular machines was recognized in previous centuries. With pioneering research efforts for the design and synthesis of molecular machines, the 2016 Nobel Prize in Chemistry was awarded to Jean-Pierre Sauvage,32,33Molecular machines originated as products of transitional chemistry fields, such as organic chemistry and supramolecular chemistry, where the observation of a single molecular machine is not always easy. This insufficiency is fortunately compensated for by developments in nanotechnology. Various probe microscopies and advanced analytical methods now enable us to directly observe, analyze, and manipulate a single molecular machine.34–36 which couples nanotechnology and other research fields including organic chemistry, supramolecular chemistry, and biochemistry, as pioneered by Masakazu Aono.37,38 The aim of nanoarchitectonics is to use molecular units to construct functional material systems with advanced features, which can be fabricated into interfacial structures exhibiting hierarchical organization.39–41 In order to make molecular machines really useful, they have to be fixed and organized onto defined sites such as interfaces. Interfaces are beneficial environments for connecting molecular functions with device outputs and biological mechanisms.42–44 Thus, molecular machines can evolve from toys to tools through the use of interfacial nanoarchitectonics.For the next stage, the organization of molecular machines using nanotechnology techniques is necessary. This new phase of molecular machine research can be supported by an emerging concept called nanoarchitectonics,In this perspective article, a shift of the working environments of molecular machines from solution to interfacial media is discussed from the viewpoint of the evolution of molecular machines from scientific toys to useful tools . Followi45,46 switching of ring positions at different stations within a rotaxane chain (molecular shuttle),47 and stepwise and directional rotation of half of a molecule relative to the remaining half (molecular rotor and/or molecular motor),48 were realized with inputs of external stimuli. These examples can be regarded as masterpiece molecules, achieved through expert design employing organic chemistry and stimulus-responsive strategies in supramolecular chemistry.Pioneering operations of molecular machines were demonstrated in solution, where intentional motions of well-designed molecules and supermolecules were induced upon application of external stimuli. As exemplified by the Nobel prize machines , rotatio49 A ring part of a bistable [1]rotaxane unit is also linked to a molecular motor. Photo-driven cis–trans isomerization of the motor induces a sliding motion of the molecular shuttle. The use of nanoarchitectonics to couple different molecular motions is an important step in combining individual machines into a unified functional system. Well-considered molecular design sometimes induces larger amplitude molecular motions by the same operational principal. The molecular shuttle shown in 50 This type of wisely designed nanoarchitectonics would be useful to convert molecular motion into larger actions such as material actuation.Molecular machines in solution environments have been actively researched on the strong basis of organic chemistry and supramolecular chemistry. Undoubtedly, these research activities support the fundamental development of molecular machine science. Various designs and motion patterns of molecular machines have been proposed. For example, Qu and co-workers successfully synthesized a molecular machine, which exhibits a coupling of the translational motion of a molecular shuttle and rotational motion of a molecular motor .49 A rin51,52 Experimental approaches under ultra-high vacuum can avoid the contribution of Brownian motion. High-resolution observations of molecular machines are usually obtained with scanning tunneling microscopy (STM). Driving fuels can be electronically supplied from the STM tip.As another playground for molecular machines, clean solid surfaces are recognized as ideal environments for the evaluation of molecular shapes and motions with excellent structural precision. Although in most cases operational conditions are impractical, such as ultralow temperature and high vacuum, the direct and precise observation of a single molecule provides indispensable insights for molecular machine science.53,54 Nanocars can be regarded as molecular machines with automobile-like motions. Mechanisms of a single molecule were semi-classically explained on the basis of quantum incoherence of their mechanical degrees of freedom by Joachim and Gimzewski.55,56 Tour and co-workers demonstrated that the motional mechanisms of their nanocar on a solid surface are almost classical under specific conditions.57 Built upon these basic understandings, molecular machine operations on clean solid surfaces have progressed in the last decade. As a demonstration of progress in this research field, the worldwide nanocar race was held in 2017, with 6 teams from France, Germany, Switzerland, USA, USA/Austria, and Japan.58,59 Operations of nanocars with regulated translational motions driven by electrical stimuli from the STM tip without touching the nanocar molecule were demonstrated in public.One representative category of molecular machine research on clean solid surfaces is centered around the nanocar (or molecular car).60 The diffusive motions of the chiral molecular walker, 1,3-bis(imidazol-1-ylmethyl)-5(1-phenylethyl)benzene benzene , on a Cu61 The accumulation of molecular shuttle motions on a surface of cantilevers can induce mechanical deformation of much larger objects of the cantilevers  surface using low-temperature STM  embedded in an air–water interface can be repeatedly and reversibly accomplished through compression and expansion of their monolayer  transformation, the latter digital conversion is accompanied with the helical transformation of cisoid to transoid  conversion.Conformation tuning of molecules can be done in both analogue mode and digital mode with interfacial nanoarchitectonics. The analogue tuning of the dihedral angles of the binaphthyl unit as a model unit was demonstrated by the continuous mechanical compression of a monolayer of molecular pliers, in which two oligo(ethylene oxide) hydrophilic heads and two alkyl hydrophobic tails are attached to the binaphthyl core .80 Mechaonolayer .81 The l82 They utilized photo-switching of a Langmuir monolayer of a photoactive amphiphile at the air–water interface. They used an amphiphile containing a bis(thiaxanthylidene) unit as a central core, with two hydrophilic tails and two hydrophobic tails at each side of the central core. Photoisomerization of the anti-folded to syn-folded geometry of the bis(thiaxanthylidene) unit as a central core induced up and down shifts of the surface tension of the water. Surface pressure increased upon photoisomerization at the two-dimensional low-density state, whereas a high-density state of the amphiphile resulted in a drop in surface pressure upon photo-irradiation, governed by the stacking state of the syn-folded conformers. Thus, the control of stacking states by addition of a matrix amphiphile, dipalmitoylphosphatidylcholine, modifies the regulation of surface tension. This means that not only is the photo-isomerization of responsive molecules an important factor for regulating surface tension, but the interfacial nanoarchitectonics of the components also are.The regulation of molecular motions and conformations can be converted to macroscopic properties at a dynamic interface. Gengler, Feringa, and co-workers demonstrated bidirectional control of the surface tension of a macroscopic liquid surface .82 They a,4a-diaza-s-indacene, the restriction of rotational motions results in fluorescence emission  complexes doubly linked by alkyl spacers. The H-shaped complexes of the submarine molecules are capable of taking various orientations at the air–water interface. At lower pressures, the submarine molecules are submerged in water, where they exhibit a weak emission. The submarine molecules are forced to float upward toward the air phase by mechanical compression of their monolayer. The weak interaction between the complex planes is broken so that one plane is exposed to the air phase. The complex plane in the air phase is free from dispersion of excitation energy due to molecular contacts under water and thus shows strong emission. Prior to mechanical compression of the monolayer of the submarine molecules, their phosphorescence is quenched but subsequently increases upon mechanical compression of the monolayer. Manipulation of the molecules at interfacial media with different dielectric constants would be an effective way to control their medium-induced photonic properties.Another specific feature of the air–water interface is a drastic change in dielectric nature across the interface. The control of molecular motion across the air–water interface can induce drastic changes in physical properties, with dependence on dielectric environments. One example was recently demonstrated as a novel concept called submarine emission .85 In thAmong various research efforts into molecular machines and related functional molecules, their usage in biological systems would be the most attractive. In particular, cell membranes provide many opportunities for molecular machines to express their potential capabilities.One of the major roles of cell membranes is the regulation of chemical potential gradients between the inside and outside of the cell. The control of material transport by artificial molecules such as molecular carriers and channels has been researched with much interest.86 On a polyimide membrane, conical-shape nanochannels were first fabricated with ion-track etching. The inside surfaces of the nanochannels were then modified with photo-sensitive azobenzene-type molecular motors. The modified nanochannels were found to be capable of autonomous transport of selective guest molecules through simultaneous irradiation with UV and visible light. In the case of β-cyclodextrin transport, β-cyclodextrin is trapped by the trans-form of azobenzene upon visible-light irradiation and the trapped β-cyclodextrin is released by UV light irradiation. Interestingly, balanced intensity between UV and visible light can facilitate mass transport better than strong intensity of a single wavelength.Molecular machines can be used for the regulation of material transport across the model membranes. Wen and co-workers demonstrated photo-driven molecular motors for mass transport across model polymer membranes .86 On a 87 The molecular swing has a 15-crown-5 part as a carrier unit with ion binding and transport capabilities, together with a lag bolt component to anchor the swing into the hydrophilic regions of the membrane. Even in the cholesterol-rich conditions of lipid membranes, high ion transport behavior was observed. The ion transport mechanism is based on numerous pathways, making the flux for transmembrane K+ transport highly efficient, corresponding to 27% better than that for gramicidin A. Anticancer activity can even be achieved by further structure optimization.Zeng and co-workers developed a new type of molecular machine, a molecular swing, for ion transport across model lipid bilayer membranes .87 The m88 A cytolytic pore-forming toxin known as aerolysin is embedded in lipid membranes. Photo-isomerization of azobenzene attached to the molecular train can modulate the speed of the train in the aerolysin pore. Based on such motional control of molecular machines in biological pores, single-molecule computing may become possible upon logic operation with selected inputs of multiple external stimuli.As reported by Zhang, Long, and co-workers, the motion of a DNA molecular train with azobenzene gears within aerolysin pores was evaluated with high temporal and spatial resolution through electrical signals.et al. . The proposed system could be applied to skin cancer cells because the affected areas can be easily exposed to visible light. Unlike healthy cells, cancer cells lack a protective stratum corneum layer. Therefore, artificial molecular motors are expected to adsorb selectively on cancer cells.Orozco UV light .90 Pancr91 On a quartz slide, a multilayer layer-by-layer film of poly and graphene oxide is first assembled, into which 1-hydroxy pyrene molecules as photoacid generators are loaded through π–π interactions with graphene oxide. Nafion is next coated as a proton conductor on the surface of the layer-by-layer film, and then proteoliposomes containing the motor protein, ATP synthase, are spread on top. The nanoarchitected artificial membrane with biomolecular motors can work as photo-activated ATP producer. Photo-irradiation deprotonates 1-hydroxy pyrene to release protons that can transmit though the membrane via the proton conductor. The generated proton gradient activates the motor proteins to synthesize ATP molecules.In addition to introducing artificial molecular machines into biological systems, the introduction of biomolecular machines into artificial supramolecular systems has become a hot topic. In natural biological systems, there are many kinds of highly complex biomolecular machines operating at biological interfacial media, such as cell membranes. Therefore, nanoarchitecting biomolecular machines into supramolecular films is a rational approach to generating bio-mimetic functional systems. For example, Li and co-workers successfully immobilized a motor protein together with a photoacid generator and proton conductor in a layer-by-layer structural motif .91 On a 92 Gold nanoparticles were immobilized on a glass substrate through magnetron sputtering, onto which proteoliposomes containing ATP synthase were spread to complete the hybrid system. Binding added alkane thiol molecules on a surface of gold nanoparticles to form a self-assembled monolayer induced the release of protons. This resulted in a proton gradient across the adjacent membrane, which formed the driving energy to rotate ATP synthase and activate ATP production. The bio-irrelevant supramolecular process, self-assembled monolayer formation, can behave like a bio-energy production process. Well-considered nanoarchitectonics efforts to couple biological molecular machines with artificial nanostructured systems could create possibilities to include various chemical processes into biomimetic energy and material conversion systems.Hybrid nanoarchitectonics with artificial nanostructures and biomolecular motors can expand categories of molecular fuels. Li and co-workers constructed hybrid systems using gold nanoparticles and the motor protein ATP synthase to expand bioenergy processes to include self-assembled monolayer chemistry .92 Gold Molecular machines were initially studied as toys in the molecular sciences. Their on-demand motions are evaluated as averaged behaviors in their solutions. Advanced nanotechnology apparatus such as STM allows us to observe and manipulate molecular machines directly. Molecular machines can be visualized as photos and movies. However, these fundamental studies may not be enough to convert molecular machines from scientific toys to useful tools.93,94 It was also demonstrated that dynamic media such as Langmuir monolayers and their transferred films can host functions of rotaxanes.95 Appropriate working media for molecular machines must be able to accept external stimuli and emit output dynamically. Dynamic interfaces would be appropriate media for this second stage of molecular machine research. Upon embedding molecular machines at the dynamic air–water interface, molecular machine functions such as molecular capture, rotation, and submarine emission are connected with macroscopic mechanical motions that are regarded as practical inputs. As more advanced examples, molecular machine operations have been recently demonstrated at biomolecular interfaces, including living cell surfaces and lipid bilayer membrane models. Science-fiction-like dreams of ultra-small machines have been realized, as seen in the recent example where artificial molecular motors drill open pores in cancer cell membranes. Molecular machines have surely become useful tools.One important key for the practical usage of molecular machines is organizing them in well-defined media. Highly sophisticated research on solid surfaces has revealed that molecular rotors are capable of synchronized and directional motions upon their association.Machine-like mechanisms are ubiquitous within life forms and carry out sophisticated functions. Indeed, organisms may be regarded as a huge organization of biomolecular machines. Life forms with biomolecular machines are the products of billions of years of evolutionary processes. We may nanoarchitect such highly complex and sophisticated functional systems with artificial molecular machines within much shorter periods. Further developments of molecular machines as useful tools require some additional research to increase their capabilities. Achieving motional and functional relays of multiple molecular machines nanoarchitected at interfaces would be an important step to realize the sophisticated conversion of materials, energy, and information. Cooperative work to apply functional molecules to cell membranes towards achieving molecular factories is a common strategy in biological research. These high functions could be mimicked through the organization of artificial molecular machines at interfacial environments. Another important factor for realizing the practical usage of molecular machines is achieving a connection between molecular-level machine outputs and practical-level macroscopic signals. Signal amplification through the concerted actions of molecular machines is a possible solution. The rational accumulation of concerted actions of molecular machines can be done through organizing assemblies of molecular machines at interfacial media. The evolution of molecular machines from toys to tools would be supported by interfacial nanoarchitectonics approaches.There are no conflicts to declare.


Mesothelioma is a rare malignant neoplasm with poor survival. It mainly affects the pleura (90%) but can arise in all serous cavities: peritoneum (5-10%), pericardium and tunica vaginalis testis (<1%). The onset of pleural mesothelioma is strictly related to asbestos exposure with a long latency time. The causal link with asbestos has also been suggested for peritoneal mesothelioma, while the importance of exposure in the onset of pericardial and tunica vaginalis testis mesotheliomas is not well known. Mesothelioma remains an aggressive and fatal disease with a five-year mortality rate higher than 95%. However, new therapeutic approaches based on molecular-targeted and immunomodulatory therapies are being explored but have conflicting results. In this context, the identification of critical targets appears mandatory. Awareness of the molecular and physiological changes leading to the neoplastic degeneration of mesothelial cells and the identification of gene mutations, epigenetic alterations, gene expression profiles and altered pathways could be helpful for selecting targetable mechanisms and molecules. In this review, we aimed to report recent research in the last 20 years focusing on the molecular pathways and prognostic factors in peritoneal mesothelioma and their possible diagnostic and therapeutic implications. Peritoneal mesothelioma (PM) is a rare malignant neoplasm that originates from the mesothelial cells lining the peritoneal serosa. PM was first reported in the early 1900s as a diffuse intraperitoneal neoplastic process associated with ascites in a young woman  of all mPM usually arises as multiple serosal nodules with thickening of the peritoneum. Adipose tissue invasion and stromal invasion represent indicative features of malignancy . HistoloBRCA (BReast CAncer), endometriosis, the period following radiation therapy for other peritoneal or pelvic neoplastic processes, and simian vacuolating virus infection  mutations, both in L858R and other catalytic domains, in a high percentage of PM patients. In different studies, ligand-dependent activation  and coactivation of EGFR and PDGFRB (Platelet Derived Growth Factor Receptor Beta) were shown, together with cooperation of these receptors with the mTOR  pathway, suggesting the potential efficacy of the combined inhibition of these cascades in PM (PI3K (Phosphoinositide 3-kinases). Varghese et al. -rearranged PM in a child, thus opening a new perspective in the molecular dissection of this entity. The presence of ALK alteration was the topic of investigation for the group of Hung et al. (ALK rearrangement was confirmed in more recent studies (STRN)-ALK fusion, an extremely rare ALK rearrangement reported in only 56 cancers of different organs  rearrangements. In 2013, Panagopoulos et al.  gene mutations have been rarely described in PM, especially in those non-asbestos related  and CDKN2A (Cyclin Dependent Kinase Inhibitor 2A). Although these genes have also been detected in the pleural form, some differences have been found between the two entities  and in Rho GTPase signalling, were found mutually exclusively mutated in a series of well-differentiated papillary mesothelioma of the peritoneum , TMEM308 (Tumor Microenvironment of Metastasis 308), and MAPK13 (Mitogen-Activated Protein Kinase 13) and reported hypermethylation of these genes in PM. The authors found a correlation between KAZALD1 and the sarcomatoid variant, showing a certain histotype distribution of molecular alterations. Bozzi et al. focused on epithelioid PM, where tumour cells were characterized by stemness and plasticity supported by epigenetic reprogramming in the context of mesenchymal epithelial reverse transcription. Thus, the authors suggesting that the PM is likely to be responsive to epigenetic regulator inhibitors, basing also on the inverse correlation between strong EZH2 expression and the loss of the BAP1 (SF3B1 (Splicing factor 3B subunit 1) which correlated with a worse prognosis    inhibitoal trial  with onlpathways , potentipathways , 53, warpathways –69. Rega cancers . Immunot cancers  with difBAP1 and other DNA repair, chromatin, and cell cycle regulators. Awareness of the molecular and physiological changes leading to the neoplastic degeneration of mesothelial cells and the identification of gene mutations, epigenetic alterations, gene expression profiles and altered pathways could be helpful for selecting targetable mechanisms and molecules.The molecular events that cause PM have not been clearly defined, and comprehensive genetic characterization remains challenging. Important steps have been made towards the definition of the molecular signature of neoplasia to identify therapeutic targets, along with the goals of other tumours. The recent published studies, particularly those based on next-generation or other high-throughput sequencing methodologies, show heterogenous molecular alterations, mostly involving Conceptualization, FF, FP, GS, and LV. Methodology, AM and FP. Data curation DC, DR, and Ad’A. Writing—original draft preparation FF and FP. Writing—review and editing GS. Supervision, GS and LV. All authors have read and agreed to the published version of the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. 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