Searching for the optimal precondition procedure for mesenchymal stem/stromal cell treatment:Facts and perspectives

Mesenchymal stem/stromal cells are potential optimal cell sources for stem cell therapies,and pretreatment has proven to enhance cell vitality and function.In a recent publication,Li et al explored a new combination of pretreatment condi-tions.Here,we present an editorial to comment on their work and provide our view on mesenchymal stem/stromal cell precondition.

Multi-site Passivation of ZnO Metal Oxides via Biomolecules for Efficient and Highly Stable Organic Solar Cells

ZnO nanoparticles(nps)among metal oxide(MOs)are proven to be essential electron transporting layers(ETLs)applied in organic solar cells(OSCs).However,intrinsic defects,interfacial charge recombination,and catalytic behavior towards the active layer restrict the applications of ZnO nps for efficient and long-term stable OSCs.The commonly available biomolecule cytidine 5'-monophosphate(CMP-OH)with phosphonic acid,its salt cytidine 5'-monophosphate disodium salt(CMP-ONa)with a phosphate group as an anchoring group and conjugated terminal functional in both analogous molecules provide carrier transfer bridge at bottom interface of the active layer.Systematized theoretical investigations and characterizations have discovered the multi-site coordination of CMP-OH towards acceptor molecules and ZnO nps.The dual-side alignment of CMP analogous molecules hinders interfacial charge recombination and enhances charge transfer potential at once.Inevitably,PM6:L8-BO-based OSCs with modified ETL obtain 18.13%efficiency,12%higher than that of unmodified nps.Besides higher efficiency,CMP-OH-based OSC devices illustrate remarkably improved thermal stability for 500 h at 85℃with 72%of initial PCE and operation stability for 2000 h with 90.1%of initial PCE.This work reveals the passivation mechanism of multi-anchoring groups towards MOs and single-functional groups towards the active layer to optimize the interface for efficient and highly stable OSCs.

Effect of decompression range on decompression limit of cervical laminoplasty

Backgrounds:Cervical posterior decompression surgery is used to relieve ventral compression indirectly by incorporating a backward shift of the spinal cord, and this indirect decompression is bound to be limited. This study aimed to determine the decompression limit of posterior surgery and the effect of the decompression range.Methods:We retrospectively reviewed the data of 129 patients who underwent cervical open-door laminoplasty through 2008 to 2012 and were grouped as follows: C4-C7 ( n = 11), C3-C6 ( n = 61), C3-C7 ( n = 32), and C2-C7 ( n = 25). According to the relative location of spinal levels within a decompression range, the type of decompression at a given level was categorized as external decompression (ED;achieved at the levels located immediately external to the decompression range margin), internal decompression (ID;achieved at the levels located immediately internal to the decompression range margin), and central decompression (CD;achieved at the levels located in the center, far from the decompression range margin). The vertebral-cord distance (VCD) was used to evaluate the decompression limit. The C2-C7 angle and VCD on post-operative magnetic resonance images were analyzed and compared between groups. The relationship between VCD and decompression type was analyzed. Moreover, the relationship between the magnitude of the ventral compressive factor and the probability of post-operative residual compression at each level for different decompression ranges was studied. Results:There was no significant kyphosis in cervical curvature (>-5°), and there was no significant difference among the groups ( F = 2.091, P = 0.105). The VCD of a specific level depended on the decompression type of the level and followed this pattern: ED < ID < CD ( P < 0.05). The decompression type of a level was sometimes affected by the decompression range. For a given magnitude of the ventral compressive factor, the probability of residual compression was lower for the group with the larger VCD at this level. Conclusions:Our study suggests that the decompression range affected the decompression limit by changing the decompression type of a particular level. For a given cervical spinal level, the decompression limit significantly varied with decompression type as follows: ED < ID < CD. CD provided maximal decompression limit for a given level. A reasonable range of decompression could be determined based on the relationship between the magnitude of the ventral compressive factor and the decompression limits achieved by different decompression ranges.

Improving Both Electron and Hole Mobilities of an Ambipolar Polymer by Integrating Sodium Sulfonate-Tethered Alkyl Side Chains

of main observation and conclusion High performance ambipolar organic semiconductors are highly desirable for organic logic circuits.Herein,we demonstrate the integration of sodium sulfonate(SS)-tethered sidechains into a diketopyrrolopyrrole-based ambipolar polymer(PDPP3T)can simultaneously improve its hole and electron transport performances either parallel or perpendicular to polymer film.Three SS-functionalized polymers(PDPP3T-XSS,x=0.025,0.05 and 0.10)were synthesized and studied.It was found that SS functionalization can reinforce interchain n-Ti interactions,slightly lower frontier orbital energy levels,produce more rod-like structures in film,and change chain-packing from edge-on to face-on fashion,but has little influence on thermal properties.More interestingly,organic field-effect transistors reported hole mobility of 0.27±0.066 cm^2.V^-1·s^-1 and electron mobility of 0.038±0.016 cm^2.V^-1·s^-1 for PDPP3T,while increased 2.4 and 5 folds to 0.64±0.087 and 0.19±0.051 cm^2.V^-1·s^-1 for PDPP3T-0.025SS,respectively.Moreover,PDPP3T-xSS devices displayed reduced threshold voltages for both hole and electron transports.Meanwhile,space charge-limited current method found SS functionalization achieved an order of magnitude increase in electron mobility and slight enhancement in hole mobility transporting perpendicular to polymer film.In-depth investigations suggest such enhancements may originate from the joint actions of chain-stacking modulation and ionic doping effect.

Regioregular and Nondestructive Graphene Functionalization for High-Performance Electrochromic and Supercapacitive Devices

To overcome two obstacles in graphene functionalization—the random distribution of functional groups and substantial lattice defects,in this contribution,we rationally bypass the universal yet destructive graphene oxide(GO)-derived methodologies and adopt reductive covalent functionalization of natural graphite.In this strategy,ultrahigh density graphene sheets with evenly distributed negative charges were intermediately yielded by potassium reduction to graphite.Subsequently,they were regioregularly and efficiently brominated by the benchmark electrophile of molecular bromine.The combined characterizations determined the graphene bromide derivative to have a molecular formula of C_(24)-Br,corresponding well with the brominated entity of the inseparable C_(24)-K^(+)graphite intercalation compounds.Due to the regular distribution of Br groups and intact hexagonal lattice of the graphene matrix,the C_(24)-Br_GBr delivers exceptional electrical properties although theπ-conjugation is partially blocked by C(sp^(3))-Br sites and greatly outperforms its counterparts derived from GO bromination.In both model applications of quickly switchable electrochromic devices and all-solid-state supercapacitors,C_(24)-Br_GBr exhibits impressive performance,which highlights the great significance and prospect of regioregular and lattice-nondestructive graphene functionalization.

Tuning Acceptor Length in Photocatalytic Donor-Acceptor Conjugated Polymers for Efficient Solar-to-Hydrogen Energy Conversion

The development of conjugated polymer photocatalysts for efficient solar-to-hydrogen energy conversion is highly desirable for the sustainability of our society.Although the construction of donor-acceptor(D-A)structure in conjugated polymer photocatalysts for solar-to-hydrogen energy conversion has been well documented,less attention has been paid on how large D and how large A units combined together could achieve the best performance.Herein,a series of D-A copolymers P(BDT-DBTSOx)(x=7,19,39,and 79)composed of a benzodithiophene(BDT)donor unit and an oligomeric dibenzo[b,d]thiophene sulfone(DBTSO)acceptor segment were synthesized and studied.It was found that the polymer photocatalytic stabilities under full-arc irradiation improved upon shortening the length of the acceptor segment.Under visible light irradiation and in the presence of 3 wt%Pt cocatalyst,P(BDT-DBTSO79)displayed the best performance with an optimal hydrogen evolution rate of 119.3±5.8 mmol·g^(-1)·h^(-1).This is 1.4-fold as that of DBTSO homopolymer and 22.5-fold as that of BDT/DBTSO alternative copolymer,highlighting the importance of acceptor length in D-A structure for achieving high photocatalytic performance.

Changing to Poly（rod-coil） Polymers： A Promising Way for an Optoelectronic Compound to Improve Its Film Formation

Good film formation is one of basic requirements for organic optoelectronic materials to achieve the capability for fabrication of large area devices. Small molecular optoelectronic compounds have a definite chemical structure and clear device performance, and thus are welcomed in the field. However, they are generally suffering from poor film formation, especially in a large area. For addressing it, this contribution proposes and demonstrates a strategy, that is, changing them into poly（rod-coil） polymers. With one optoelectronic compound [BDT（DTBT）2] and three poly（rod-coil） polymers （P1, P2, and P3） having different non-conjugated coil segments as examples, the work clearly shows that the change to poly（rod-coil） polymers keeps many basic optoelectronic properties of the refer- ence compound, including light absorption in solution, bandgap and frontier orbital energy levels, but suppresses strong intermolecular interactions and crystalline structure in film state. Further comparisons on film formation quality on glass and ITO glass illustrate that all the three polymers have a better film formation property than the reference compound.