Ta4C3 Nanosheets as a Novel Therapeutic Platform for Photothermal-Driven ROS Scavenging and Immune Activation against Antibiotic-Resistant Infections in Diabetic Wounds.

The accumulation of excessive reactive oxygen species (ROS) and recurrent infections with drug-resistant bacteria pose significant challenges in diabetic wound infections, often leading to impediments in wound healing. Addressing this, there is a critical demand for novel strategies dedicated to treating and preventing diabetic wounds infected with drug-resistant bacteria. Herein, 2D tantalum carbide nanosheets (Ta4C3 NSs) have been synthesized through an efficient and straightforward approach, leading to the development of a new, effective nanoplatform endowed with notable photothermal properties, biosafety, and diverse ROS scavenging capabilities, alongside immunogenic attributes for diabetic wound treatment and prevention of recurrent drug-resistant bacterial infections. The Ta4C3 NSs exhibit remarkable photothermal performance, effectively eliminating methicillin-resistant Staphylococcus aureus (MRSA) and excessive ROS, thus promoting diabetic wound healing. Furthermore, Ta4C3 NSs enhance dendritic cell activation, further triggering T helper 1 (TH1)/TH2 immune responses, leading to pathogen-specific immune memory against recurrent MRSA infections. This nanoplatform, with its significant photothermal and immunomodulatory effects, holds vast potential in the treatment and prevention of drug-resistant bacterial infections in diabetic wounds.

Clinical effect of nice knot-assisted minimally invasive titanium elastic nail fixation to treat Robinson 2B midshaft clavicular fracture.

BACKGROUND: The treatment of completely displaced midshaft clavicle fractures is still controversial, especially Robinson 2B fractures. Titanium elastic nail (TEN) fixation is a good option for simple fractures, but no reports exist on its use in complex fractures. This study aimed to present a surgical method using the Nice knot-assisted TEN fixation to treat Robinson 2B midshaft clavicular fractures. METHODS: A retrospective analysis of 29 patients who underwent fixation with TEN and had a 1-year postoperative follow-up between 2016 and 2020 was performed. The fractures were classified as Robinson type 2B1 in 17 cases and type 2B2 in 12 cases. Length of the incision, postoperative shoulder function Disability of Arm Shoulder and Hand (DASH) score and Constant score, complications rate, and second surgical incision length were recorded. RESULTS: The length of the incision was 2-6 cm (average 3.7 cm). All incisions healed by first intention, and no infection or nerve injury occurred. The Constant score was 92-100 (average 96) and the DASH score was 0-6.2 (mean, 2.64). TEN bending and hypertrophic nonunion occurred in one case (3.4%) and implant irritation occurred in four cases (13.8%) Fixation implants were removed at 12-26 months (mean, 14.6 months) after surgery, and the length of the second incision was 1-2.5 cm (average 1.3 cm). CONCLUSIONS: Intramedullary fixation by TEN is approved as a suitable surgical technique in clavicular fracture treatment. Nice knot-assisted fixation provides multifragmentary fracture stabilization, contributing to good fracture healing. Surgeons should consider this technique in treating Robinson 2B midshaft clavicular fractures. TRIAL REGISTRATION: Retrospectively registered. This study was approved by the Ethics Committee of Wuxi Ninth People's Hospital (LW20220021).

Clinical efficacy of the topical application of tranexamic acid in tendon release in the hand: A randomized controlled trial.

PURPOSE: To study the clinical effectiveness of the topical application of tranexamic acid in hand tendon release. METHODS: This was a randomized controlled trial conducted after receiving approval from the local ethics committee according to guidelines from the Helsinki Declaration. Eighty patients who underwent hand tendon release operation in our hospital from January 2021 to December 2022 were included and randomly divided into 2 groups. Patients in the tranexamic acid group (40 cases) received intraoperative topical application of 2 g of tranexamic acid after tendon release, while patients in the conventional group (40 cases) did not receive topical application of tranexamic acid during operation. The operation time, perioperative hemoglobin changes, total blood loss, incidence of early postoperative complications, and total active movement (TAM) before surgery and 6 months after surgery were compared between the 2 groups. The continuous variable which follows normal distribution expressed by mean ± SD and used t-test to compare between groups. Meanwhile, categorical variables were used by Chi-square test, and a p < 0.05 indicated that the differences were statistically significant. RESULTS: Both groups were followed up for 7 - 18 months, with a mean of 10.3 months. Postoperative decrease in hemoglobin was significantly less in the tranexamic acid group than in the conventional group (t = 7.611, p < 0.001). The total blood loss in the tranexamic acid group (74.33 ± 20.50) mL was less than that in the conventional group (83.05 ± 17.73) mL, and the difference was statistically significant (p < 0.05). Both groups showed improvement in thumb/finger flexion and extension range of motion after surgery, and the TAM improved compared with those before surgery, and the difference was statistically significant (p < 0.001). The TAM improved more significantly in the tranexamic acid group (87.68° ± 10.44°) than in the conventional group (80.47° ± 10.93°) at 6 months after surgery, with a statistically significant difference (t = 3.013, p < 0.001). There was no significant difference in operation time and incidence of early postoperative complications between the 2 groups (p = 0.798, 0.499, respectively). CONCLUSION: The topical application of tranexamic acid during hand tendon release can significantly reduce postoperative bleeding and improve surgical efficacy, which is worth promoting.

Treatment of inferior pole patella fracture using Krackow suturing combined with the suture bridge technique.

PURPOSE: To evaluate the feasibility and clinical effect of Krackow suturing combined with the suture bridge technique for the treatment of acute inferior pole patella fracture. METHODS: In this study, 18 patients with acute inferior pole patella fracture who received treatment using Krackow suturing combined with the suture bridge technique between January 2019 and March 2020 were retrospectively reviewed. There were 10 men and 8 women, with an average age of 50.1 years (range 24-69 years). X-ray examinations were performed to assess fracture healing and the Insall-Salvati index. The clinical effect was measured by the range of motion of the knee joint and the Böstman scale. RESULTS: Patients were followed up for 13-26 months, with an average follow-up period of 19.6 months. X-ray indicated that fracture union had occurred in all patients by 10.1 weeks after surgery on average (range 8-14 weeks). The mean Insall-Salvati index immediately after surgery and at the final follow-up was 0.98 ± 0.07 and 0.90 ± 0.22, respectively (P > 0.05). At the last follow-up, the mean flexion and extension ranges for the knee joint were 135.8° ± 8.8° and - 2.8° ± 3.9°, respectively, and the mean Böstman scale was 28.9 ± 1.1 points. Functional recovery was excellent in 17 patients and good in one patient, resulting in an overall good/excellent recovery rate of 100%. CONCLUSIONS: Our results indicated that Krackow suturing combined with the suture bridge technique can achieve stable fracture fixation, provides good clinical outcomes in the treatment of acute inferior pole patella fracture, and is worthy of clinical application.

Radio-anatomical study of anterior-posterior placement sacroiliac screw channel.

PURPOSE: The outlet of the classic sacroiliac screw (SIS) cannot be precisely controlled by aiming devices, which may lead to malpositioned implants and neurovascular and visceral injury. This study aimed to radio-anatomically measure the parameters of the channel for anterior-posterior placement SIS (AP-SIS), which can be placed percutaneously with an aiming device. METHODS: Pelvic CT scan data of 80 healthy adults (40 males and 40 females) with an average age of 45 years (range 20-70 years) were collected. The length (L), width (W), height (H), cortical bone spacing (M), camber angle (E), anteversion angle (F), cross-sectional safety angle (P) and sagittal safety angle (Q) of the channel were measured by CT or Mimics software. RESULTS: The L, W, H, M, E, F, P and Q measures of S1 were 109.2 ± 8.0 mm, 18.5 ± 1.9 mm, 21.7 ± 1.7 mm, 8.1 ± 0.4 mm, 44.2 ± 3.2°, 42.4 ± 3.6°, 16.8 ± 1.1°, and 19.4 ± 2.0°, respectively, for S1, and 113.5 ± 9.4 mm, 18.2 ± 1.5 mm, 21.7 ± 1.7 mm, 7.7 ± 0.4 mm, 44.7 ± 3.2°, 31.2 ± 2.7°, 13.8 ± 1.0° and 15.4 ± 1.4°, respectively, for S2. Of the L measures, the intra-iliac segment was slightly longer than the intra-sacral segment. All parameters showed significant sex-related differences (p < 0.05). CONCLUSION: The AP-SIS channels of S1-2 have sufficient width and length to accommodate a cancellous screw with a Φ 7.0-8.0 mm and a length 90-130 mm. The intra-iliac segment is a long channel screw with better mechanical properties over classic SIS.

Application of the induced membrane technique of tibia using extracorporeal vs. intracorporeal formation of a cement spacer: a retrospective study.

BACKGROUND: There were two ways of preparing the cement spacer: intracorporeal and extracorporeal formation. This study aimed to investigate the outcomes of extracorporeal vs. intracorporeal formation of a spacer using the induced membrane technique (IMT) for repairing bone defects of the tibia. METHODS: Sixty-eight patients with tibial defects treated with IMT were analyzed retrospectively. According to the mode of bone cement preparation, patients were divided into intracorporeal and extracorporeal groups (36 vs. 32 respectively). All patients were followed up for 12-48 months (average 18.7 months). The time interval between the first and second stages, the time required to remove the spacer, injury of the IM or bone ends, bone healing and infection control, as well as the functional recovery (Johner-Wruhs scoring), were compared. RESULTS: There was no significant difference in the preoperative data between the two groups (P > 0.05). There was no significant difference in the time interval (12.64 ± 4.41vs. 13.22 ± 4.96 weeks), infection control (26/28 vs. 20/23), bone healing time (7.47 ± 2.13vs. 7.50 ± 2.14 mos), delayed union (2/36 vs. 2/32), nonunion (2/36 vs. 1/32), an excellent or good rate of limb functional recovery (30/36 vs. 26/32) between the intracorporeal and extracorporeal groups (P > 0.05). However, the time required to remove (3.97 ± 2.34 min) was longer and the injury of IM or bone ends (28/36) was greater in the intracorporeal group than those in the extracorporeal group (0.56 ± 0.38 min and 1/32, respectively), showing a significant difference (P < 0.05). CONCLUSION: Both approaches were shown to have similar effects on bone defect repair and infection control. However, intracorporeal formation had advantages in terms of additional stability, while extracorporeal formation had advantages in terms of removal. Therefore, the specific method should be selected according to specific clinical needs. We recommended the extracorporeal or the modified extracorporeal formation in most cases.

Catalytic asymmetric umpolung reactions of imines.

The carbon-nitrogen double bonds in imines are fundamentally important functional groups in organic chemistry. This is largely due to the fact that imines act as electrophiles towards carbon nucleophiles in reactions that form carbon-carbon bonds, thereby serving as one of the most widely used precursors for the formation of amines in both synthetic and biosynthetic settings. If the carbon atom of the imine could be rendered electron-rich, the imine could react as a nucleophile instead of as an electrophile. Such a reversal in the electronic characteristics of the imine functionality would facilitate the development of new chemical transformations that convert imines into amines via carbon-carbon bond-forming reactions with carbon electrophiles, thereby creating new opportunities for the efficient synthesis of amines. The development of asymmetric umpolung reactions of imines (in which the imines act as nucleophiles) remains uncharted territory, in spite of the far-reaching impact such reactions would have in organic synthesis. Here we report the discovery and development of new chiral phase-transfer catalysts that promote the highly efficient asymmetric umpolung reactions of imines with the carbon electrophile enals. These catalysts mediate the deprotonation of imines and direct the 2-azaallyl anions thus formed to react with enals in a highly chemoselective, regioselective, diastereoselective and enantioselective fashion. The reaction tolerates a broad range of imines and enals, and can be carried out in high yield with as little as 0.01 mole per cent catalyst with a moisture- and air-tolerant operational protocol. These umpolung reactions provide a conceptually new and practical approach to chiral amino compounds.

Control of chemoselectivity in asymmetric tandem reactions: Direct synthesis of chiral amines bearing nonadjacent stereocenters.

This paper describes the mechanistic insight-guided development of a catalyst system, employing a phenolic proton donor catalyst in addition to a cinchonium-derived phase-transfer catalyst, to control the chemoselectivity of two distinct intermediates, thereby enabling the desired asymmetric tandem conjugate addition-protonation pathway to dominate over a number of side-reaction pathways to provide a synthetic approach for the direct generation of optically active amines bearing two nonadjacent stereocenters.

Pd-Catalyzed γ-C(sp3)-H Fluorination of Free Amines.

The first example of free amine γ-C(sp3)-H fluorination is realized using 2-hydroxynicotinaldehyde as the transient directing group. A wide range of cyclohexyl and linear aliphatic amines could be fluorinated selectively at the γ-methyl and methylene positions. Electron withdrawing 3,5-disubstituted pyridone ligands were identified to facilitate this reaction. Computational studies suggest that the turnover determining step is likely the oxidative addition step for methylene fluorination, while it is likely the C-H activation step for methyl fluorination. The explicit participation of Ag results in a lower energetic span for methylene fluorination and a higher energetic span for methyl fluorination, which is consistent with the experimental observation that the addition of silver salt is desirable for methylene but not for methyl fluorination. Kinetic studies on methyl fluorination suggest that the substrate and PdL are involved in the rate-determining step, indicating that the C-H activation step may be partially rate-determining. Importantly, an energetically preferred pathway has identified an interesting pyridone-assisted bimetallic transition state for the oxidative addition step in methylene fluorination, thus uncovering a potential new role of the pyridone ligand.

Large transparent display based on liquid crystal technology.

A large transparent liquid crystal display (LCD) prototype with ultrahigh transmittance and good see-through property is demonstrated in this paper. The transmittance reaches more than 20% by introducing the RGBW pixel arrangement, a thin color filter process, a large aperture ratio design, as well as antireflective polarizer film. The see-through image quality is also greatly improved by suppressing the blurring by using domain reduction pixel design. All these approaches are applicable for large LCD panel products, and we expect broad applications of large transparent LCDs in the near future.

Retraction of transporting bone segment during Ilizarov bone transport.

BACKGROUND: Retraction of transporting bone segment (TBS) may occur when the fixator of the TBS is removed prior to full consolidation of the distracted callus, which has adverse effect on the healing of the docking site. However, there are few reports on the retraction of TBS. The purpose of this study is to analyze the causes and risk factors of the retraction of TBS. METHODS: The clinical data of 37 cases with tibial bone defect treated by Ilizarov bone transport were analyzed retrospectively, in whom the TBS fixator was removed prior to full consolidation of the distracted callus and union of the docking site. Bivariate correlation was used to analyze relationship between the retraction distance of TBS and potential risk factors including age, gender, course, length of bone defect, number of operations, size of TBS, transport distance, timing and time interval of removal of TBS fixator. Risk factors with significant level were further identified using multivariate linear regression. RESULTS: Bivariate correlation showed that the timing of removal was negatively correlated with the retraction distance, and the time interval and transport distance were positively correlated with the retraction distance(p < 0.05), the age, gender, course, length of bone defect, size of TBS and number of operations were not correlated with the retraction distance(p > 0.05). Multivariate linear regression of the 3 risk factors showed that the timing of removal and time interval were the main risk factors affecting the retraction distance (p < 0.05), but the transport distance was not (p > 0.05). CONCLUSION: The traction forces of TBS endured from the soft tissues and the unconsolidated distracted callus have elastic properties, which can make retraction of TBS. The timing of removal and time interval are the main risk factors of the retraction of TBS. In the case of early removal, another external fixation or quickly converted to internal fixation should be performed to avoid the adverse effect of more retraction.

Application of multiple wrapped cancellous bone graft methods for treatment of segmental bone defects.

BACKGROUND: The aims of this study were to discuss the principle, therapeutic effect and influencing factors of multiple wrapped cancellous bone graft methods for treatment of segmental bone defects. METHODS: This study retrospectively analyzed the therapeutic effect of different wrapped autologous cancellous bone graft techniques on 51 patients aged (34.5 ± 11.5) years with segmental bone defects. Cancellous bones were wrapped with titanium mesh (n = 9), line mesh (n = 10), line suturing or line binding cortical block, (n = 13), or induced membrane (n = 19). The bone defeats were as follows: tibia (n = 23), radial bone (n = 10), humerus (n = 8), ulnar bone (n = 7), and femur (n = 3). The defect lengths were (5.9 ± 1.1) cm. The functionary recovery of adjacent joint was evaluated by the Paley's method and DASH, respectively. RESULTS: The incision healed by first intention in 48 cases and secondary healing in 3 cases. All patients were followed up for 19.1 ± 7.1 (12-48) months. Other than one patient with nonunion who received a secondary bone graft, all the patients were first intention of bone healing (the healing rate was 98.0%). The healing time was 6.1 ± 2.1 (3-15) months. There were no significant differences in the healing time among the 4 groups (χ2 = 1.864, P = 0.601). The incidence of complications in the grafted site was 11.8%, whereas it was 21.6% in the harvest site. At the last follow-up, all the patients had recovered and were able to engage in weight-bearing activities. The functional recovery was good to excellent in 78.4% of cases, there were no significant difference among the 4 groups (χ2 = 5.429, P = 0.143). CONCLUSIONS: Wrapped cancellous bone grafting is a modified free bone graft method that can be used in the treatment of small and large segmental bone defects as it prevents loosening and bone absorption after bone grafting. The effect of bone healing is related with the quality and quantity of grafted bone, stability of bone defects, property of wrapping material and peripheral blood supply.

Surgical treatment of avulsion fracture around joints of extremities using hook plate fixation.

PURPOSE: This study proposed to access the clinical outcome of avulsion fractures around joints of extremities using the hook plate. METHODS: A total of 60 patients with avulsion fractures of joints admitted in our hospital between January 2011 and June 2016 were performed the surgery of hook plate fixation. Functional recovery was evaluated using the Lysholm knee score, Kaikkonen ankle injury score, Mayo elbow and wrist function score, and Neer shoulder function score. RESULTS: All the patients were healed within 3 months after surgery with stage I healing incision without vascular or nerve injuries. The average follow-up period was 18.1 months. At the last follow-up, no instability of joints, looseness of internal fixation or traumatic arthritis was observed. Mild joint fibrosis occurred in 5 cases. A total of 57 patients were well recovered with the excellent and good rate of 95%. Three patients with humeral avulsion fracture of the greater tuberosity had shoulder joint adhesion and peri humeral inflammation at the last follow-up due to the poor cooperation for early rehabilitation exercise. In the last follow-ups, the functional score of the affected limb was markedly greater than that in the 3-month follow-ups (p < 0.05). CONCLUSION: Hook plate fixation has the therapeutic effect on treating avulsion fractures around joints of extremities with the advantages of reliable fixation, early rehabilitation after operation, high recovery rates of joint function, wide indications, and convenient uses.

Overcoming the Limitations of γ- and δ-C-H Arylation of Amines through Ligand Development.

L,X-Type transient directing groups (TDGs) based on a reversible imine linkage have emerged as broadly useful tools for C-H activation of ketones and free amines. However, competitive binding interactions among multiple reaction components (TDG itself, substrate, and substrate-TDG adduct) with the palladium catalyst often lead to the formation of multiple unreactive complexes, rendering ligand development extremely challenging. Herein, we report the finding of versatile 2-pyridone ligands that addresses these problems and significantly improves the γ-methylene arylation of alkyl amines, extending the coupling partners to a wide range of medicinally important heteroaryl iodides and even previously unreactive heteroaryl bromides. The combination of an appropriate transient directing group and pyridone ligand has also enabled the δ-arylation of alkyl amines. Notably, our transient directing group design reveals the importance of matching the size of the Pd-chelation with different transient directing groups and the size of palladacycles generated from γ- and δ-C-H bonds: TDGs that coordinate with Pd(II) to form a six-membered chelate are selective toward γ-C-H bonds, whereas TDGs that coordinate with Pd(II) via a five-membered chelate tend to activate δ-C-H bonds. These findings provide an avenue for developing protecting group free and selective C-H functionalization using the transient directing group strategy.

Ilizarov technique: Bone transport versus bone shortening-lengthening for tibial bone and soft-tissue defects.

OBJECTIVE: To compare the outcomes of bone transport and bone shortening-lengthening by Ilizarov technique for treatment of tibial bone and soft-tissue defects. METHODS: Fifty patients with tibial bone and soft-tissue defects were treated by Ilizarov technique from January 2007 to June 2016. Two subgroups were treated by either bone transport (group A) containing 28 cases or bone shortening-lengthening (group B) including 22 cases. RESULTS: Bony union was achieved at the distracted sites with a mean of 236 days in group A, while 240 days in group B, showing no significant difference (t = -0.931, P = 0.308). The mean fixation index was 3.91 d/mm and 3.92 d/mm, respectively. There was no obvious difference (t = 2.839, P = 0.006) of the mean union time at the docking sites with 376 days and 320 days, respectively. According to the Paley's criterion, 21 patients had excellent bony union and 5 good in group A, as compared to 18 excellent and 4 good in group B, but no significant difference (X2 = -0.308, P = 0.741) was observed. The functional results were excellent in 11 patients, good in 10 and fair in 7, as well as 15 complications in group A, compared with 7 excellent, 10 good and 5 fair, together with 12 complications in group B, and there were no remarkable difference (X2 = -0.323, P = 0.751; X2 = -0.590, P = 0.562). CONCLUSION: Overall, the outcomes are similar of bone transport or bone shortening-lengthening by using Ilizarov technique for treatment of tibial bone and soft-tissue defects, although the latter has less union time and higher healing rate.

Versatile Alkylation of (Hetero)Aryl Iodides with Ketones via ß-C(sp3)-H Activation.

We report Pd(II)-catalyzed ß-C(sp3)-H (hetero)arylation of a variety of ketones using a commercially available 2,2-dimethyl aminooxyacetic acid auxiliary. Facile installation and removal of the auxiliary as well as its superior scope for both ketones and (hetero)aryl iodides overcome the significant limitations of the previously reported ß-C(sp3)-H arylation of ketones. The ready availability of ketones renders this reaction a broadly useful method for alkyl-(hetero)aryl coupling involving both primary and secondary alkyls.

Spontaneous Amino-yne Click Polymerization: A Powerful Tool toward Regio- and Stereospecific Poly(ß-aminoacrylate)s.

Efficient synthesis of poly(enamine)s has been a great challenge because of their poor stability, poor solubility, and low molecular weights. In this work, a spontaneous amino-yne click polymerization for the efficient preparation of poly(enamine)s was established, which could proceed with 100% atom efficiency under very mild conditions without any external catalyst. Through systematic optimization of the reaction conditions, several soluble and thermally stable poly(ß-aminoacrylate)s with high molecular weights (Mw up to 64400) and well-defined structures were obtained in excellent yields (up to 99%). Moreover, the polymerization can perform in a regio- and stereospecific fashion. Nuclear magnetic resonance spectra analysis revealed that solely anti-Markovnikov additive products with 100% E-isomer were obtained. The reaction mechanism was well demonstrated with the assistance of density functional theory calculations. In addition, by introducing the tetraphenylethene moiety, the resulting polymers exhibit unique aggregation-induced emission characteristics and could be applied in explosives detection and bioimaging. This polyhydroamination is a new type of click polymerization and opens up enormous opportunities for preparing functional polymeric materials.

Efficient and Regioselectivity-Tunable Metal-Free Polycycloaddition of Activated Azide and Alkynes.

The transition-metal catalyzed and metal-free click polymerizations have been developed as powerful tools for the construction of functional polymers with linear and hyperbranched structures. The latter provides a thorough solution for the completely removing metallic residues from the products encountered in the former. Compared to the activated alkyne-azide metal-free click polymerization, the activated azide-alkyne one is rarely studied. In this Communication, a perfluorophenyl-activated azide of hexane-1,6-diyl-bis(4-azido-2,3,5,6-tetrafluorobenzoate) is rationally designed and facilely prepared. Through systematical optimization of the reaction conditions, an efficient metal-free perfluorophenylazide-alkyne polycycloaddition is established, and polytriazoles with high molecular weights (up to 166 000) and excellent solubility are obtained in excellent yields (up to 93%) under mild reaction conditions. Interestingly, the regioselectivity of the reaction could be fine-tuned by the solvents and diyne monomers. Therefore, this work provides not only a powerful tool for the preparation of functional polytriazoles, but also an attractive method for fine-tuning their regioregularity.

Metal-Free Poly-Cycloaddition of Activated Azide and Alkynes toward Multifunctional Polytriazoles: Aggregation-Induced Emission, Explosive Detection, Fluorescent Patterning, and Light Refraction.

The metal-free click polymerization (MFCP) of activated alkynes and azides or activated azide and alkynes have been developed into powerful techniques for the construction of polytriazoles without the obsession of metallic catalyst residues problem. However, the MFCP of activated azides and alkynes is rarely applied in preparation of functional polytriazoles. In this paper, soluble multifunctional polytriazoles (PIa and PIb) with high weight-average molecular weights (Mw up to 32 000) are prepared via the developed metal-free poly-cycloaddition of activated azide and alkynes in high yields (up to 90%). The resultant PIa and PIb are thermally stable, and show aggregation-induced emission characteristics, enabling their aggregates to detect explosives with superamplification effect. Moreover, thanks to their containing aromatic rings and polar moieties, PIa and PIb exhibit high refractive indices. In addition, they can also be cross-linked upon UV irradiation to generate 2D fluorescent patterning due to their remaining azide groups and containing ester groups. Thus, these multifunctional polytriazoles are potentially applicable in the optoelectronic and sensing fields.

Cinchonium Betaines as Efficient Catalysts for Asymmetric Proton Transfer Catalysis: The Development of a Practical Enantioselective Isomerization of Trifluoromethyl Imines.

We have developed a new class of cinchonium betaine catalysts bearing both a base moiety and an aromatic moiety as an N-substituent of the quinuclidine motif. These cinchonium betaines were found to promote proton transfer catalysis with 1000-5000 turnovers per 24 h, thereby enabling us to realize highly efficient enantioselective isomerization of trifluoromethyl imines to provide a practical access to optically active trifluoromethylated amines.