Ionic Liquid-accelerated Growth of Covalent Organic Frameworks with Tunable Layer-stacking.

Layer-stacking behaviors are crucial for two-dimensional covalent organic frameworks (2D COFs) to define their pore structure, physicochemical properties, and functional output. So far, fine control over the stacking mode without complex procedures remains a grand challenge. Herein, we proposed a "key-cylinder lock mimic" strategy to synthesize 2D COFs with a tunable layer-stacking mode by taking advantage of ionic liquids (ILs). The staggered (AB) stacking (unlocked) COFs were exclusively obtained by incorporating ILs of symmetric polarity and matching molecular size; otherwise, commonly reported eclipsed (AA) stacking (locked) COFs were observed instead. Mechanistic study revealed that AB stacking was induced by a confined interlocking effect (CIE) brought by anions and bulky cations of the ILs inside pores ("key" and "cylinder", respectively). Excitingly, this strategy can speed up production rate of crystalline powders (e.g., COF-TAPT-Tf@BmimTf2N in merely 30 minutes) under mild reaction conditions. This work highlights the enabling role of ILs to tailor the layer stacking of 2D COFs and promotes further exploration of their stacking mode-dependant applications.

Building Porous Ni(Salen)-Based Catalysts from Waste Styrofoam via Autocatalytic Coupling Chemistry for Heterogeneous Oxidation with Molecular Oxygen.

The development of robust and industrially viable catalysts from plastic waste is of great significance, and the facile construction of high performance heterogeneous catalyst systems for phenol-quinone conversions remains a grand challenge. Herein, a feasible strategy is demonstrated to reclaim Styrofoam into hierarchically porous nickel-salen-loaded hypercrosslinked polystyrene (PS@Ni-salen) catalysts with high activities through an unusual autocatalytic coupling route. The salen is immobilized onto PS chain by Friedel-Crafts alkylation of benzyl chloride derivatives, and the generated hydrogen chloride coordinately promotes the simultaneous crosslinking and bridge formation between aromatic rings via a Scholl coupling route, leading to hierarchically porous networks. After the metallization with Ni, the resultant networks exhibit high catalytic activity for the oxidation of 2,3,6-trimethylphenol to 2,3,5-trimethyl-1,4-benzoquinone under mild conditions (303 K, 1 bar of O2 ). This catalyst also demonstrates attractive recycling performance without an obvious loss of catalytic efficiency over five consecutive cycles. This methodology might provide a potential sustainable alternative to construct environmentally benign and cost-effective catalysts for specific organic transformation.

[Open reduction and mini-plate internal fixation for the treatment of fracture and dislocation of coccyx].

OBJECTIVE: To explore the therapeutic methods of fracture and dislocation of coccyx and evaluate its curative effects. METHODS: From May 2002 to March 2010,56 patients with fracture and dislocation of coccyx were divided into surgical treatment group and non-surgical treatment group. There were 7 males and 20 females in surgical treatment group with an average age of (48.1 +/- 0.6) years (ranged, 29 to 62 years), treated with open reduction and mini-plate internal fixation. There were 8 males and 21 females in non-surgical treatment group with an average age of (47.5 +/- 0.9) years (ranged, 19 to 54 years),treated with manipulative reduction. All patients were underwent X-ray examination and were finally diagnosed before treatment. Clinical symptoms and Visual Analogue Scales (VAS) of all patients were statistically analyzed before and after treatment. RESULTS: There was no significant difference between two groups in gender, age, BMI index and VAS evaluation. All patients were followed up from 12 to 25 months with an average of 17.2 months. In surgical treatment group,there were 26 cases with I/a incision and 1 case with II/a incision; the excellent rate of clinical symptom was respectively 92.6% and 100% at leaving hospital and final follow-up; the improvement rate of VAS was 97.6% and was excellent result;internal fixtures were removed at the 1 to 2 years after treatment and no unwell symptoms occurred; VAS of all patients in the group was 0 point. In non-surgical treatment group,the excellent rate of clinical symptom was respectively 72.4% and 82.8% at leaving hospital and final follow-up; the improvement rate of VAS was 72.1% and was good result. There was significant difference in clinical results between two groups (P<0.05). CONCLUSION: The results indicated that fracture and dislocation of coccyx should be treated in time. For the treatment of patients with manipulative reduction failures, instability reduction by X-ray examination and serious rectal irritation, open reduction and mini-plate internal fixation can obtain satisfactory results.

Efficacy evaluation for the treatment of unstable lumbar disc herniation by traditional and modified lamina osteotomy replantation.

BACKGROUND: The traditional lamina osteotomy replantation method is prone to nerve root injury and low back pain recurrence. Our team has proposed a modified approach that improves the osteotomy site and its fixation procedure. The aim of this study was to evaluate the clinical efficacy of traditional and modified lamina replantation methods in treating unstable lumbar disc herniation. METHODS: From March 2008 to August 2011, 124 patients with unstable lumbar disc herniation were enrolled and randomly divided into the following two groups according to random digital table: group A (traditional group) consisting of 61 patients who underwent traditional laminectomy replantation, and group B (modified group) consisting of 63 patients who underwent modified lamina replantation. Both surgeries were performed by the same surgeons. The two groups had no significant difference in gender, age, symptoms, time of onset and the prominent segment. Visual analogue scale (VAS), Oswertry disability index (ODI), and Japanese Orthopaedic Association (JOA) scores, operative time, blood loss, complication rate, radiographic healing rates, and low back pain recurrence rates were compared between the two groups. RESULTS: There were 121 patients followed up for more than one year, and the follow-up rate was 97.6%. Nerve injury occurred in two patients (3.3%) in the modified group and 12 patients (20.0%) in the traditional group. Dural injury occurred in one patient (1.6%) in the modified group and seven patients (11.7%) in the traditional group. Pseudarthrosis occurred in two patients in the modified group and in 18 patients in the traditional group with 1-year fusion rates of 96.7% and 70.0%, respectively. Recurrence of lower back pain after one year was noted in three patients (4.9%) in the modified group, and in 15 (25.0%) in the traditional group. Leg pain recurrence was noted in one patient (1.6%) in the modified group and in three cases (5.0%) in the traditional group. The one-year healing rates of nerve injury, dural injury, replantation lamina and low back pain recurrence rates after one year were significantly different (P < 0.05) between the two groups. At two weeks, three months, six months and one year postoperatively, both groups had significant improvement in VAS, ODI, and JOA scores from their preoperative values (P < 0.05). No significant difference was detected between the short term postoperative scores between groups A and B (P > 0.05). However, a significant difference was found one year later (P < 0.05). CONCLUSIONS: Compared to the traditional approach, the modified technique for lamina replantation showed lower rates of dural and nerve damage, a higher lamina healing rate, a lower back pain recurrence rate, and better clinical scores. It is a safe and effective operation for lumbar spine surgery.

[Clinical natural development in human meniscus injury].

OBJECTIVE: To investigate the changes of clinic and wound edge of the meniscus without treatment in order to provide a theoretical basis for clinical treatment. METHODS: From January 2001 to December 2011,68 patients with knee injury without diagnosis and treatment were selected in the study. According to clinical symptoms (pain,interlocking,instability, etc.) and knee MRI,32 patients were diagnosed as meniscus injury and underwent the arthroscopy. Total meniscectomy was performed in 32 cases on account of impossible repair of the meniscus. There were 21 males and 11 females,ranging in age from 15 to 49 years old with an average age of 25 years old,with an average time from diagnosis to arthroscopy for 46 weeks. Observation indexes included 1Preoperative and postoperative Lysholm scores of knee. 2Position,type and status of injury by arthroscopy. 3Observation of histology. With the procedure as follow: tissue samples were taken from different positions of the edge of the meniscus wound,and were divided into two parts. One part of sample was fixed with formalin, sliced with paraffin imbedding,and observed under an electron microscope after HE staining,and the other part of the sample was fixed with glutaraldehyde of 3%,sliced with ethoxyline imbedding ,and observed under an electron microscope after Lead Citrate staining. RESULTS: Thirty-two patients were followed up more than one year. There was significant differences in Lysholm scores bewteen preoperative and postoperative 3 months (t=15.6,P<0.01). Arthroscopy showed typical differences in 28 cases between the middle and the two ends of the wound edge and atypical differences in 4 cases. Light microscope showed typical manifestations in 26 cases, a few epithelioid cells could been seen fat the middle of the wound edge as well as cells tissue healing (such as fibroblasts) at the junction of each end,and atypical manifestations in 2 cases. Electron microscope showed typical manifestation in 25 cases and atypical manifestations in 3 cases. Typical manifestations in electron microscope showed the atrophic state tions in 25 cases and atypical manifestations in 3 cases. Typical manifestations electron microscope showed the atrophic state of nuclei and kytoplasm of cell (isogenous cells and epithelioid cells) at the middle of the wound edge; at the either junction of the wound edge, the fibroblasts exhibited an enlarged volume with many protuberances; the nuclei also increased in size, and the cytoplasm contained major rough endoplasmic reticulum, free ribosomes and Golgi complex; chondrocytes were round or oval with a large,round nucleus ; a large amount of rough endoplasmic reticulum and many free ribosomes could be observed in the cytoplasm;cartilage lacunae were observed surrounding chondrocytes. CONCLUSION: Weight loading activities with meniscus injury without treatment or before healing will increase the length of the wound and aggravate clinical symptoms. These findings indicate that early diagnosis and treatment combined with timely and effective immobilization is a key to the healing of meniscus injury and avoiding further surgery. The recent clinical effect of total meniscectomy is satisfacory in treating impossible repair meniscus.

[Treatment of unstable lumbar intervertebral disc herniation by modified lamina osteotomy replantation].

OBJECTIVE: To evaluate the clinical effects of the modified lamina replantation for the treatment of unstable lumbar intervertebral disc herniation. METHODS: From March 2009 to August 2011,63 patients with unstable lumbar intervertebral disc herniation were treated by discectomy, interbody fusion, pedicle screw fixation, and modified lamina replantation. There were 33 males and 30 females with an average age of 48.4 years old ranging from 22 to 68 years old. The average duration of disease was 38.8 months ranging from 3 months to 13 years. All patients had lower back and leg pains. X-ray,CT and MR results showed unstable lumbar intervertebral disc herniation. Preoperative and postoperative ODI, JOA scores, complication incident rates,radiographic healing rates,and lower back and leg pain recurrence rates were observed and recorded. RESULTS: Sixty-two incisions were healed at first stage, 1 at second stage. There were no complications such as deep vein thrombosis, intervertebral infection and so on. Sixty-one patients were followed up for more than one year, and the mean duration was 33 months. Nerve and dural injury occurred in 2 patients and 1 patient respectively. One-year fusion happened in 58 patients while the recurrence of lower back pain and leg pain after 1 year were noted in 4 patients and 1 patient respectively. ODI, and JOA scores were respectively re-assessed at 2 weeks, 6 months and 1 year after the operation, and the results showed a significant difference from the preoperative scores (P < 0.05). CONCLUSION: Modified lamina replantation for unstable lumbar intervertebral disc herniation showed lower rates of dural and nerve damage, as well as a higher lamina healing rate, lower back and leg pain recovery rate, and a better clinical score. It is a safe and efficient operation choice for lumbar spine surgery.