Search

Cyclodehydrogenation is an important ring-formation reaction that can directly produce planar-conjugated carbon-based nanomaterials from nonplanar molecules. However, inherently high C-H bond energy necessitates a high temperature during dehydrogenation, and the ubiquity of C - H bonds in molecules and small differences in their bond energies hinder the selectivity of dehydrogenation. Here, we report a room-temperature cyclodehydrogenation reaction on Au(111) via radical addition of open-shell resonance structures and demonstrate that radical addition significantly decreases cyclodehydrogenation temperature and further improves the chemoselectivity of dehydrogenation. Using scanning tunneling microscopy and non-contact atomic force microscopy, we visualize the cascade reaction process involved in cyclodehydrogenation and determine atomic structures and molecular orbitals of the planar acetylene-linked oxa-nanographene products. The nonplanar intermediates observed during progression annealing, combined with density functional theory calculations, suggest that room-temperature cyclodehydrogenation involves the formation of transient radicals, intramolecular radical addition, and hydrogen elimination; and that the high chemoselectivity of cyclodehydrogenation arises from the reversibility and different thermodynamics of radical addition step., (© 2024. The Author(s).)

Background: Extracorporeal shock wave therapy (ESWT) is increasingly being recognized as an advantageous alternative for treating non-union due to its efficacy and minimal associated complications. Non-union following Bernese periacetabular osteotomy (PAO) is particularly challenging, with a reported 55% delayed union and 8% non-union. Herein, we highlight a unique case of ischial non-union post-PAO treated successfully with a structured ESWT regimen., Case Summary: A 50-year-old patient, diagnosed with left ischial non-union following the PAO, underwent six cycles of ESWT treatment across ten months. Each cycle, spaced four weeks apart, consisted of five consecutive ESWT sessions without anesthesia. Regular X-ray follow-ups showed progressive disappearance of the fracture line and fracture union. The patient ultimately achieved a satisfactory asymptomatic recovery and bone union., Conclusion: The results from this case suggest that this ESWT regimen can be a promising non-invasive treatment strategy for non-union following PAO., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2024. Published by Baishideng Publishing Group Inc. All rights reserved.)

Precisely introducing topological defects is an important strategy in nanographene crystal engineering because defects can tune π-electronic structures and control molecular assemblies. The synergistic control of the synthesis and assembly of nanographenes by embedding the topological defects to afford two-dimensional (2D) crystals on surfaces is still a great challenge. By in-situ embedding ladder bipyrazinylene (LBPy) into acene, the narrowest nanographene with zigzag edges, we have achieved the precise preparation of 2D nonbenzenoid heteroacene crystals on Au(111). Through intramolecular electrocyclization of o-diisocyanides and Au adatom-directed [2+2] cycloaddition, the nonbenzenoid heteroacene products are produced with high chemoselectivity, and lead to the molecular 2D assembly via LBPy-derived interlocking hydrogen bonds. Using bond-resolved scanning tunneling microscopy, we determined the atomic structures of the nonbenzenoid heteroacene product and diverse organometallic intermediates. The tunneling spectroscopy measurements revealed the electronic structure of the nonbenzenoid heteroacene, which is supported by density functional theory (DFT) calculations. The observed distinct organometallic intermediates during progression annealing combined with DFT calculations demonstrated that LBPy formation proceeds via electrocyclization of o-diisocyanides, trapping of heteroarynes by Au adatoms, and stepwise elimination of Au adatoms., (© 2024 Wiley-VCH GmbH.)

Two-dimensional (2D) crystal-to-crystal transition is an important method in crystal engineering because of its ability to directly create diverse crystal materials from one crystal. However, steering a 2D single-layer crystal-to-crystal transition on surfaces with high chemo- and stereoselectivity under ultra-high vacuum conditions is a great challenge because the transition is a complex dynamic process. Here, we report a highly chemoselective 2D crystal transition from radialene to cumulene with retention of stereoselectivity on Ag(111) via retro-[2 + 1] cycloaddition of three-membered carbon rings and directly visualize the transition process involving a stepwise epitaxial growth mechanism by the combination of scanning tunneling microscopy and non-contact atomic force microscopy. Using progression annealing, we found that isocyanides on Ag(111) at a low annealing temperature underwent sequential [1 + 1 + 1] cycloaddition and enantioselective molecular recognition based on C-H···Cl hydrogen bonding interactions to form 2D triaza[3]radialene crystals. In contrast, a higher annealing temperature induced the transformation of triaza[3]radialenes to generate trans -diaza[3]cumulenes, which were further assembled into 2D cumulene-based crystals through twofold N-Ag-N coordination and C-H···Cl hydrogen bonding interactions. By combining the observed distinct transient intermediates and density functional theory calculations, we demonstrate that the retro-[2 + 1] cycloaddition reaction proceeds via the ring opening of a three-membered carbon ring, sequential dechlorination/hydrogen passivation, and deisocyanation. Our findings provide new insights into the growth mechanism and dynamics of 2D crystals and have implications for controllable crystal engineering.

On-surface synthesis, as a bottom-up synthetic method, has been proven to be a powerful tool for atomically precise fabrication of low-dimensional carbon nanomaterials over the past 15 years. This method relies on covalent coupling reactions that occur on solid substrates such as metal or metal oxide surfaces under ultra-high-vacuum conditions, and the achievements with this method have greatly enriched fundamental science and technology. However, due to the complicated reactivity of organic groups, distinct diffusion of reactants and intermediates, and irreversibility of covalent bonds, achieving the high selectivity of covalent coupling reactions on surfaces remains a great challenge. As a result, only a few on-surface covalent coupling reactions, mainly involving dehalogenation and dehydrogenation homocoupling, are frequently used in the synthesis of low-dimensional carbon nanosystems. In this Perspective, we focus on the development and synthetic applications of on-surface cross-coupling reactions, mainly Ullmann, Sonogashira, Heck, and divergent cross-coupling reactions.

Background: Many studies have focused on the femoral tunnel technique and fixation method, but few studies have involved the tibial tunnel technique and fixation method. The all-inside technique is one of the new techniques that has been described in recent years. All-inside anterior cruciate ligament (ACL) reconstruction is based on a tibial socket instead of a full tunnel. This method has many potential advantages., Aim: To compare clinical outcomes of knee ACL autograft reconstruction using all-inside quadrupled semitendinosus (AIST) and traditional hamstring tendon (TBT) techniques., Methods: From January 2017 to October 2019, the clinical data of 80 patients with ACL reconstruction were retrospectively analyzed, including 67 males and 13 females. The patients had an average age of 24.3 ± 3.1 years (age range: 18-33 years). The AIST technique was used in 42 patients and the TBT technique was used in 38 patients. The time between operation and injury, operative duration, postoperative visual analogue scale (VAS) score and knee functional recovery were recorded and compared between the two groups. The International Knee Documentation Committee (IKDC) and Lysholm scoring system were used to comprehensively evaluate clinical efficacy., Results: Eighty patients were followed for 24-36 mo, with an average follow-up duration of 27.5 ± 1.8 mo. There were no significant differences in the time between surgery and injury, operative duration, IKDC and Lysholm scores of the affected knee at the last follow-up evaluation between the two groups. There were significant differences in VAS scores 1 d, 3 d, 7 d, 2 wk and 1 mo after surgery ( P < 0.05). There was no significant difference in VAS score at 3 mo, 6 mo and 1 year after operation., Conclusion: The efficacy of the AIST ACL reconstruction technique was comparable to the TBT technique, but the postoperative pain was less with the AIST technique. Thus, the AIST technique is an ideal treatment choice for ACL reconstruction., Competing Interests: Conflict-of-interest statement: All the authors report having no relevant conflicts of interest for this article., (©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background: Celecoxib has been used to treat hip discomfort and functional difficulties associated with osteonecrosis of the femoral head (ONFH), although significant adverse reactions often follow long-term use. Extracorporeal shock wave therapy (ESWT) can delay the progression of ONFH, alleviate the pain and functional limitations it causes, and avoid the adverse effects of celecoxib., Aim: To investigate the effects of individual ESWT, a treatment alternative to the use of celecoxib, in alleviating pain and dysfunction caused by ONFH., Methods: This was a randomized, controlled, double-blinded, non-inferiority trial. We examined 80 patients for eligibility in this study; 8 patients were excluded based on inclusion and exclusion criteria. A total of 72 subjects with ONFH were randomly assigned to group A ( n = 36; celecoxib + alendronate + sham-placebo shock wave) or group B ( n = 36; individual focused shock wave [ESWT based on magnetic resonance imaging three-dimensional (MRI-3D) reconstruction] + alendronate). The outcomes were assessed at baseline, at the end of treatment, and at an 8-wk follow-up. The primary outcome measure was treatment efficiency after 2 wk of intervention using the Harris hip score (HHS) (improvement of 10 points or more from the baseline was deemed sufficient). Secondary outcome measures were post-treatment HHS, visual analog scale (VAS), and Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) scores., Results: After treatment, the pain treatment efficiency of group B was greater than that of group A (69% vs 51%; 95%CI: 4.56% to 40.56%), with non-inferiority thresholds of -4.56% and -10%, respectively. Furthermore, the HHS, WOMAC, and VAS scores in group B dramatically improved during the follow-up period as compared to those in group A ( P < 0.001). After therapy, the VAS and WOMAC in group A were significantly improved from the 2 nd to 8 th wk ( P < 0.001), although HHS was only significantly altered at the 2 wk point ( P < 0.001). On the 1 st d and 2 nd wk after treatment, HHS and VAS scores were different between groups, with the difference in HHS lasting until week 4. Neither group had severe complications such as skin ulcer infection or lower limb motor-sensory disturbance., Conclusion: Individual shock wave therapy (ESWT) based on MRI-3D reconstruction was not inferior to celecoxib in managing hip pain and restrictions associated with ONFH., Competing Interests: Conflict-of-interest statement: The authors declare that they have no conflicts of interest., (©The Author(s) 2023. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background: Recurrent anterior shoulder instability is a common traumatic injury, the main clinical manifestation of which is recurrent anteroinferior dislocation of the humeral head. The current follow-up study showed that the effect of arthroscopic Bankart repair is unreliable., Aim: To evaluate the clinical efficacy of arthroscopy with subscapularis upper one-third tenodesis for treatment of anterior shoulder instability, and to develop a method to further improve anterior stability and reduce the recurrence rate., Methods: Between January 2015 and December 2018, male patients with recurrent anterior shoulder instability were selected. One hundred and twenty patients had a glenoid defect < 20% and 80 patients had a glenoid defect > 20%. The average age was 25 years (range, 18-45 years). Patients with a glenoid defect < 20% underwent arthroscopic Bankart repair with a subscapularis upper one-third tenodesis. The patients with a glenoid defect > 20% underwent an arthroscopic iliac crest bone autograft with a subscapularis upper one-third tenodesis. All patients were assessed with Rowe and Constant scores., Results: The average shoulder forward flexion angle was 163.6° ± 8.3° and 171.8° ± 3.6° preoperatively and at the last follow-up evaluation, respectively. The average external rotation angle when abduction was 90° was 68.4° ± 13.6° and 88.5° ± 6.2° preoperatively and at the last follow-up evaluation, respectively. The mean Rowe scores preoperatively and at the last follow-up evaluation were 32.6 ± 3.2 and 95.2 ± 2.2, respectively ( P < 0.05). The mean Constant scores preoperatively and at the last follow-up evaluation were 75.4 ± 3.5 and 95.8 ± 3.3, respectively ( P < 0.05). No postoperative dislocations were recorded by the end of the follow-up period., Conclusion: Arthroscopy with subscapularis upper one-third tenodesis was effective for treatment of recurrent anterior shoulder instability independent of the size of the glenoid bone defect, enhanced anterior stability of the shoulder, and did not affect postoperative range of motion of the affected limb., Competing Interests: Conflict-of-interest statement: All the authors report no relevant conflicts of interest for this article., (©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.)

Background: According to the global cancer burden data released in 2020, breast cancer (BC) has become the most common cancer in the world. Similar to those of other cancers, the present methods used in clinic for diagnosing early BC are invasive, inaccurate, and insensitive. Hence, new non-invasive methods capable of early diagnosis are needed., Methods: We applied next-generation sequencing and analyzed the messenger RNA (mRNA) profiles of plasma extracellular vesicles (EVs) derived from 14 BC patients and 6 patients with benign breast lesions. We used 3 regression models, namely support vector machine (SVM), linear discriminate analysis (LDA), and logistic regression (LR), to develop classifiers for use in making predictive BC diagnoses; and used 259 plasma samples, including those obtained from 144 patients with BC, 72 patients with benign breast lesions, and 43 healthy women, which were divided into training groups and validation groups to verify their performances as classifiers by quantitative reverse transcription polymerase chain reaction (RT-qPCR). The area under the curve (AUC) and accuracy, sensitivity, and specificity of the classifiers were cross-validated with the leave-1-out cross-validation (LOOCV) method., Results: Among all combinations assessed with the 3 different regression models, an 8-mRNA combination, named EXOB mRNA , exhibited high performance [accuracy =71.9% and AUC =0.718, 95% confidence interval (CI): 0.652 to 0.784] in the training cohort after LOOCV was performed, showing the largest AUC in the SVM model. The mRNAs in EXOB mRNA were HLA-DRB1, HAVCR1, ENPEP, TIMP1, CD36, MARCKS, DAB2, and CXCL14. In the validation cohort, the AUC of EXOB mRNA was 0.737 (95% CI: 0.636 to 0.837). In addition, gene function and pathway analyses revealed that different levels of gene expression were associated with cancer., Conclusions: We developed a high-performing predictive classifiers including 8 mRNAs from plasma extracellular vesicles for diagnosing breast cancer., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://dx.doi.org/10.21037/gs-21-275). The authors have no conflicts of interest to declare., (2021 Gland Surgery. All rights reserved.)

Neurolathyrism is a unique neurodegeneration disease caused by β-N-oxalyl-L-α, β- diaminopropionic (β-ODAP) present in grass pea seed (Lathyrus stativus L.) and its pathogenetic mechanism is unclear. This issue has become a critical restriction to take full advantage of drought-tolerant grass pea as an elite germplasm resource under climate change. We found that, in a human glioma cell line, β-ODAP treatment decreased mitochondrial membrane potential, leading to outside release and overfall of Ca 2+ from mitochondria to cellular matrix. Increased Ca 2+ in cellular matrix activated the pathway of ECM, and brought about the overexpression of β1 integrin on cytomembrane surface and the phosphorylation of focal adhesion kinase (FAK). The formation of high concentration of FA units on the cell microfilaments further induced overexpression of paxillin, and then inhibited cytoskeleton polymerization. This phenomenon turned to cause serious cell microfilaments distortion and ultimately cytoskeleton collapse. We also conducted qRT-PCR verification on RNA-sequence data using 8 randomly chosen genes of pathway enrichment, and confirmed that the data was statistically reliable. For the first time, we proposed a relatively complete signal pathway to neurolathyrism. This work would help open a new window to cure neurolathyrism, and fully utilize grass pea germplasm resource under climate change.

Background: Currently, the available treatments for long bone nonunion (LBN) are removing of focus of infection, bone marrow transplantation as well as Ilizarov methods etc. Due to a high percentage of failures, the treatments are complex and debated. To develop an effective method for the treatment of LBN, we explored the use of human autologous bone mesenchymal stems cells (hBMSCs) along with extracorporeal shock wave therapy (ESWT)., Materials and Methods: Sixty three patients of LBN were subjected to ESWT treatment and were divided into hBMSCs transplantation group (Group A, 32 cases) and simple ESWT treatment group (Group B, 31 cases)., Results: The patients were evaluated for 12 months after treatment. In Group A, 14 patients were healed and 13 showed an improvement, with fracture healing rate 84.4%. In Group B, eight patients were healed and 13 showed an improvement, with fracture healing rate 67.7%. The healing rates of the two groups exhibited a significant difference ( P < 0.05). There was no significant difference for the callus formation after 3 months treatment ( P > 0.05). However, the callus formation in Group A was significantly higher than that in the Group B after treatment for 6, 9, and 12 months ( P < 0.05)., Conclusion: Autologous bone mesenchymal stems cell transplantation with ESWT can effectively promote the healing of long bone nonunions.

To observe the effect of extracorporeal shock waves (ESWs) on bone marrow mesenchymal stem cells (MSCs) in patients with avascular necrosis of the femoral head, we collected bone marrow donated by patients and then cultivated and passaged MSCs in vitro using density gradient centrifugation combined with adherence screening methods. The P3 generation MSCs were divided into the ESW group and the control group. The cell counting kit for MSCs detected some proliferation differences. Cytochemistry, alkaline phosphatase staining and Alizarin red staining were used to determine alkaline phosphatase content. Simultaneously, real-time polymerase factor α1, osteocalcin and peroxisome proliferator-activated receptor γ. Together, the results of our study first indicate that moderate ESW intensity, which is instrumental in enhancing MSC proliferation, inducing conversion of MSCs into osteoblasts, and inhibiting differentiation of MSCs into adipocytes from MSCs, is one of the effective mechanisms for treating avascular necrosis of the femoral head., (Copyright © 2016 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.)

Objective: To prepare the cross-linked chitosan/poly(acrylic acid)/poly (ethylene oxide) nanofibrous membrance loaded with pseudo-ginseng and to determine its characteristics., Methods: Pseudo-ginseng entrapped in chitosan, poly (acrylic acid), poly (ethylene oxide) nanofibrous membrane loaded with pseudo-ginseng was prepared by electrospinning and thermal treatment method. The surface morphology of fiber membrane was observed by scanning electron microscopy and the chemical structures were characterized by infrared spectroscopy; the thermal decomposition temperature was analyzed by the thermogravimetric analysis. UV-Vis spectra were used to evaluate the in vitro release properties., Results: The average diameter of the prepared nanofibrous particles was (181 ± 71) nm. The tensile strength of fiber membrane increased by 35.3% and the decomposition temperature increased from 197℃ to 208℃ after crosslinking. Compared with casting film, the structure of fiber membrane increased the release rate and the overall amount of active components from pseudo-ginseng., Conclusion: The preparation of chitosan fiber loaded with pseudo-ginseng is simple and the dispersion of pseudo-ginseng is homogeneous. This fibrous pseudo-ginseng exhibited good release performance, providing a new Chinese medicine formulation.

It is not clear whether the method used in functional brain-network related research can be applied to explore the feature binding mechanism of visual perception. In this study, we investigated feature binding of color and shape in visual perception. Functional magnetic resonance imaging data were collected from 38 healthy volunteers at rest and while performing a visual perception task to construct brain networks active during resting and task states. Results showed that brain regions involved in visual information processing were obviously activated during the task. The components were partitioned using a greedy algorithm, indicating the visual network existed during the resting state. Z-values in the vision-related brain regions were calculated, confirming the dynamic balance of the brain network. Connectivity between brain regions was determined, and the result showed that occipital and lingual gyri were stable brain regions in the visual system network, the parietal lobe played a very important role in the binding process of color features and shape features, and the fusiform and inferior temporal gyri were crucial for processing color and shape information. Experimental findings indicate that understanding visual feature binding and cognitive processes will help establish computational models of vision, improve image recognition technology, and provide a new theoretical mechanism for feature binding in visual perception.

To understand the adverse drug reaction (ADR) induced by Mailuoning injection. 162 ADRs due to the drug were retrieved from national medical journals of 1988-2007 for statistics. It was shown that there was no relationship between ADR and dosage, but ADR appeared mostly in middle-aged and old groups, and more in male than in female. The occurrence of ADR was commonly within 30 min after injection. It involved injuries of various systems and organs. As for the 123 cases of allergy, 38 were anaphylactic shock (accounting for 23.46%), two people died. ADR characterized by immediate type on initial use and tachy type. It should be paid more attention to the Mailuoning injection for the immediate hypersensitivity reaction (such as anaphylactic shock).

Objective: To study the influence of separation of distal tibiofibular syndesmosis on ankle joint and to compare various operative methods so as to find suitable stabilization for separated distal tibiofibular syndesmosis., Methods: From July 1997 to July 2002, we treated 87 patients (64 males and 23 females, aged 18-54 years) with separation of distal tibiofibular syndesmosis, among whom, 79 were combined with fracture of malleolus. Manipulative reduction, internal fixation with cancellous screws and external fixation with plaster support were performed on 37 patients, fixation with plate and screws for fibular fracture and fixation with cancellous screws for distal tibiofibular syndesmosis on 34 patients, and repair of the distal tibiofibular ligaments with tendon of peroneus longus, reduction of the separated distal tibiofibular syndesmosis, and fixation with cancellous screws on 16 patients. The ankle joint had been dorsiflexed for 30 degrees when the distal tibiofibular syndesmosis was fixed with cancellous screws. And the cancellous screws were taken out at 8-10 weeks after operation., Results: These patients were followed up for at least two years. The curative effects were assessed according to the complaints of the patients and the contour, function and radiogram of the ankle joint: excellent in 55 patients (63%), good in 18 patients (21%), and fair in 14 patients (16%). Separation of distal tibiofibular syndesmosis recurred in 2 patients, who underwent a reoperation for repairing the distal tibiofibular ligaments with tendon of peroneus longus and recovered. One cancellous screw was broken off. No necrosis developed in the anterior skin of the ankle mortise., Conclusions: Separation of distal tibiofibular syndesmosis can be treated with various reasonable operations. Repair with tendon of the peroneus longus can get excellent outcomes for complete separation of the distal tibiofibular syndesmosis.