Predictors of Postoperative Outcomes after Arthroscopic Partial Meniscectomy: A Retrospective Analysis.

OBJECTIVE: Arthroscopic partial meniscectomy is a widely used surgical technique for treating meniscus injuries, while individual differences in postoperative outcomes remain a significant concern. This retrospective study aimed to identify the factors influencing clinical outcomes following arthroscopic partial meniscectomy. METHODS: We retrospectively examined the clinical data of 52 patients who underwent arthroscopic partial meniscectomy at our institution from January to May 2022. Observation indicators, including gender, age, type of medical insurance, various surgeons, the self-pay portion of hospital costs, and total hospital costs, were systematically recorded. Subjective symptoms were evaluated with ΔTenger, ΔLysholm, and International Knee Documentation Committee (IKDC) scores during follow-up. The trends of the above questionnaires and potential predictors were statistically evaluated through regression analysis. RESULTS: Binary logistic analysis revealed that female patients (OR: 32.42; 95% confidence interval [CI]: 2.22, 473.86) and higher preoperative visual analog scale (VAS) (odds ratio [OR]: 3.58; 95% CI: 1.55, 8.28) were significantly associated with FP Lysholm score. Similarly, patients with elevated preoperative VAS (OR: 1.47; 95% CI: 1.01, 2.15) were significantly more likely to have FP IKDC scores. Multiple linear regression analysis revealed that traumatic meniscus tear (ß = -0.324; 95% CI: -0.948, -0.036; p = 0.035) emerged as a negative independent predictor of ΔTegner, while higher preoperative VAS scores (ß = 0.330; 95% CI: 0.013, 0.217; p = 0.028) were identified as positive independent predictors of ΔTegner. The duration of symptoms (ß = -0.327; 95% CI: -0.010, -0.001; p = 0.023) had a negative impact on the ΔLysholm scores. Factors such as body mass index (BMI) (ß = -0.250; 95% CI: -1.000, -0.020; p = 0.042), duration of symptoms (ß = -0.302; 95% CI: -0.009, -0.001; p = 0.014), and preoperative VAS (ß = -0.332; 95% CI: -1.813, -0.250; p = 0.011) were negatively associated with ΔIKDC scores. CONCLUSION: The study offers insights into multiple factors for patient outcomes after arthroscopic partial meniscectomy. Orthopedic surgeons need to consider variables such as gender, BMI, duration of symptoms, preoperative VAS, and the traumatic/degenerative types of meniscal tears to optimize postoperative outcomes.

Repair of Sciatic Nerve Defect in Rats With Acellular Nerve Allograft Carrying Vascular Endothelial Cells.

BACKGROUND: Acellular nerve allografts (ANAs) were developed to replace the autologous nerve grafts (ANGs) to fill the peripheral nerve defects. Poor vascularization relative to ANGs has been a limitation of application of ANAs. METHODS: A total of 60 female Sprague-Dawley rats were assigned 3 groups. The rats in A group received ANGs, the rats in B group received ANAs, and the rats in C group were transplanted with ANA carrying endothelial cells (ANA + ECs). In the 1st, 2nd, 4th, and 12th postoperative weeks, 5 rats were selected from each group for evaluating sciatic function index (SFI), electrophysiology, maximum tetanic force recovery rate, tibialis anterior muscle weights recovery rate, and microvessel density. In the 12th postoperative week, the nerves were harvested and stained with toluidine blue and observed under an electron microscope to compare nerve fibers, myelin width, and G-ratio. RESULTS: All the rats survived. In the first and second postoperative weeks, more microvessels were found in the ANA + EC group. In the 12th postoperative week, the nerve fibers were more numerous, and G-ratio was smaller in the C group compared with the B group. The compound muscle action potential and maximum tetanic force recovery rate in the tibialis anterior muscle in the C group were better than those in the B group in the 12th postoperative week. The A group showed better performances in electrophysiology, maximum tetanic force, muscle wet weight, and nerve regeneration. CONCLUSION: ANA + ECs can promote early angiogenesis, promoting nerve regeneration and neurological function recovery.

[Advances of the regulatory mechanism of cyclin, cyclin- dependent kinases and related kinase inhibitors in cell cycle progression].

Cell cycle plays a crucial role in cell development. Cell cycle progression is mainly regulated by cyclin dependent kinase (CDK), cyclin and endogenous CDK inhibitor (CKI). Among these, CDK is the main cell cycle regulator, binding to cyclin to form the cyclin-CDK complex, which phosphorylates hundreds of substrates and regulates interphase and mitotic progression. Abnormal activity of various cell cycle proteins can cause uncontrolled proliferation of cancer cells, which leads to cancer development. Therefore, understanding the changes in CDK activity, cyclin-CDK assembly and the role of CDK inhibitors will help to understand the underlying regulatory processes in cell cycle progression, as well as provide a basis for the treatment of cancer and disease and the development of CDK inhibitor-based therapeutic agents. This review focuses on the key events of CDK activation or inactivation, and summarizes the regulatory processes of cyclin-CDK at specific times and locations, as well as the progress of research on relevant CDK inhibitor therapeutics in cancer and disease. The review concludes with a brief description of the current challenges of the cell cycle process, with the aim to provide scientific references and new ideas for further research on cell cycle process.

Noninvasive diagnosis of AIH/PBC overlap syndrome based on prediction models.

Autoimmune liver diseases (AILDs) are life-threatening chronic liver diseases, mainly including autoimmune hepatitis (AIH), primary biliary cholangitis (PBC), and AIH-PBC overlap syndrome (OS), which are difficult to distinguish clinically at early stages. This study aimed to establish model to achieve the purpose of the diagnosis of AIH/PBC OS in a noninvasive way. A total of 201 AILDs patients were included in this retrospective study who underwent liver biopsy during January 2011 to December 2020. Serological factors significantly associated with OS were determined by the univariate analysis. Two multivariate models based on these factors were constructed to predict the diagnosis of AIH/PBC OS using logistic regression and random forest analysis. The results showed that immunoglobulins G and M had significant importance in both models. In logistic regression model, anti-Sp100, anti-Ro-52, anti-SSA, or antinuclear antibody positivity were risk factors for OS. In random forest model, activated partial thromboplastin time and ɑ-fetoprotein level were important. To distinguish PBC and OS, the sensitivity and specificity of logistic regression model were 0.889 and 0.727, respectively, and the sensitivity and specificity of random forest model were 0.944 and 0.818, respectively. In conclusion, we established two predictive models for the diagnosis of AIH/PBC OS in a noninvasive method and they showed better performance than Paris criteria for the definition of AIH/PBC OS.

One step excision combined with unilateral transforaminal intervertebral fusion via minimally invasive technique in the surgical treatment of spinal dumbbell-shaped tumors: A retrospective study with a minimum of 5 years' follow-up.

Introduction: Spinal dumbbell-shaped tumors are rare, usually benign tumors with intraspinal and paravertebral components connected through intervertebral foramen. Complete excision is often performed through traditional open surgery (TOS). The efficacy and long-term outcomes of minimally invasive surgery (MIS) have not been reported to date in resection of dumbbell-shaped spinal tumors. Purpose: The purpose was to evaluate the efficacy and long-term outcomes of minimally invasive resection combined with unilateral transforaminal intervertebral fusion (TIF) through comparing with TOS in the treatment of spinal dumbbell-shaped tumors. Methods: Fifteen patients underwent MIS and 18 patients underwent TOS. Thoracic dumbbell-shaped tumors were directly exposed after removal of costotransverse joints, adjacent rib components, unilateral hemilamina, and facet joints. Lumbar dumbbell-shaped tumors were completely exposed after removal of transverse processes, unilateral hemilamina, and facet joints. Whether for minimally invasive resection or traditional open removal, dumbbell-shaped tumors were completely excised and unilateral TIF was performed to guarantee spinal stability. All patients were followed up for 5 years at least. Results: The mean length of surgical incision for two groups was 3.47 ± 0.37 vs. 6.49 ± 0.39 cm (p < 0.05). The average duration of the operation was 131.67 ± 26.90 vs. 144.17 ± 23.59 min (p > 0.05). The mean blood loss was 172.00 ± 48.79 vs. 285.83 ± 99.31 ml (p < 0.05). No blood transfusions were required in the two groups. The median length of hospitalization was 6 vs. 10 days (range: 5-8 vs. 7-14 days). The patients of two groups were monitored for an average of 65.93 ± 3.88 vs. 65.78 ± 3.56 months. At 5-year follow-up, all patients presented with normal neurological function (American Spinal Injury Association scale E). The Oswestry Disability Index in the MIS group decreased significantly more than the TOS group. No spondylolisthesis or spinal instability were found in the follow-up period. There was no recurrence of any spinal tumor 5 years after surgery. Conclusions: Spinal dumbbell-shaped tumors can be safely and effectively treated with minimally invasive resection combined with unilateral TIF. Compared with TOS, MIS offers a reduced length of surgical incision, blood loss, hospital stay, and postoperative pain. This surgical protocol might provide an alternative for the treatment of spinal dumbbell-shaped tumors.

[Advances of long non-coding RNA encoded micro-peptides].

Long non-coding RNA (lncRNA) refers to non-coding RNA longer than 200 nt, with one or more short open reading frames (sORF), which encode functional micro-peptides. These functional micro-peptides often play key roles in various biological processes, such as Ca2+ transport, mitochondrial metabolism, myocyte fusion, cellular senescence and others. At the same time, these biological processes play a key role in the regulation of body homeostasis, diseases and cancers development and progression, embryonic development and other important physiological processes. Therefore, studying the potential regulatory mechanisms of micro-peptides encoded by lncRNA in organisms will help to further elucidate the potential regulatory processes in organisms. Furthermore, it will provide a new theoretical basis for the subsequent targeted treatment of diseases and improvement of animal growth performance. This review summarizes the latest research progress in the field of lncRNA-encoded micro-peptides, as well as the progress in the fields of muscle physiological regulation, inflammation and immunity, common human cancers, and embryonic development. Finally, the challenges of lncRNA-encoded micro-peptides are briefly described, with the aim to facilitate subsequent in-depth research on micro-peptides.

Functional Micropeptides Encoded by Long Non-Coding RNAs: A Comprehensive Review.

Long non-coding RNAs (lncRNAs) were originally defined as non-coding RNAs (ncRNAs) which lack protein-coding ability. However, with the emergence of technologies such as ribosome profiling sequencing and ribosome-nascent chain complex sequencing, it has been demonstrated that most lncRNAs have short open reading frames hence the potential to encode functional micropeptides. Such micropeptides have been described to be widely involved in life-sustaining activities in several organisms, such as homeostasis regulation, disease, and tumor occurrence, and development, and morphological development of animals, and plants. In this review, we focus on the latest developments in the field of lncRNA-encoded micropeptides, and describe the relevant computational tools and techniques for micropeptide prediction and identification. This review aims to serve as a reference for future research studies on lncRNA-encoded micropeptides.

No difference in postoperative efficacy and safety between autograft and allograft in anterior cruciate ligament reconstruction: a retrospective cohort study in 112 patients.

Background: Arthroscopic anterior cruciate ligament reconstruction (ACLR) is the best treatment choice for returning to pre-injury activities following ACL rupture. Although allografts are considered an effective alternative to autografts, there is still controversy regarding the safety and effectiveness of this procedure, especially concerning the risk of postoperative infection and disease transmission. The purpose of this study was to compare the efficacy outcomes and safety between allografts and autografts in primary ACLR. Methods: The retrospective analysis involved 112 patients (58 patients received allogeneic tendons and 54 patients received autologous hamstring tendons) who underwent primary ACLR. All patients were followed up and evaluated on admission and at 1 week, 3 months, 6 months, and 1 year postoperatively. The efficacy outcome of the ACLR was evaluated by International Knee Documentation Committee (IKDC) score and physical examinations (Lachman test, anterior drawer test, and pivot shift test). The safety outcome of allografts and autografts was compared by investigating the occurrence of postoperative complications, including postoperative inflammation and potential disease transmission. The benefits of each operation for surgeons and patients were also analyzed, including the length of surgical incision and operative time. Results: There was no significant difference in the demographic and clinical characteristics between the allograft and autograft groups. The two cohorts proved to be similar in terms of the acute or chronic nature of the cruciate ligament and the incidence of concomitant meniscal surgery. Arthroscopic ACLR was performed in all patients. The physical examinations were all positive before surgery and negative immediately after the operation. The KT-1000 and IKDC scores of two groups significantly decreased than pre-operative ones (P<0.05), but the difference between the two groups was not statistically significant (P>0.05). At final follow-up, all patients had returned to their pre-injury activities. Allografts showed no increased risk for postoperative infection or potential disease transmission relative to autografts. Conclusions: The outcomes of reconstructed ACL with allografts were similar to those of autographs. Moreover, the safety of allografts showed to be comparable to that of autografts, especially concerning postoperative infection and disease transmission. Therefore, the surgical option should be chosen wisely according to the patient's condition.

A random forest model predicts responses to infliximab in Crohn's disease based on clinical and serological parameters.

BACKGROUND: Infliximab (IFX) has revolutionised the treatment for Crohn's disease (CD) recently, while a part of patients show no response to it at the end of the induction period. We developed a random forest-based prediction tool to predict the response to IFX in CD patients. METHODS: This observational study retrospectively enrolled the patients diagnosed with active CD and received IFX treatment at the Gastroenterology Department in Xiangya Hospital of Central South University between January 2017 and December 2019. The baseline data were recorded in the beginning and were used as predictor variables to construct models to forecast the outcome of the response to IFX. RESULTS: Our cohort identified a total of 174 patients finally with a response rate of 29.3% (51/174). The area under the receiver operating characteristic curve (AUC) for the model, based on the random forest was 0.90 (95%CI: 0.82-0.98), compared to the logistic regression model with AUC of 0.68 (95%CI: 0.52-0.85). The optimal cut-off value of the random forest model was 0.34 with the specificity of 0.94, the sensitivity of 0.81 and the accuracy of 0.85. We demonstrated a strong association of IFX response with the levels of complement C3 (C3), high density lipoprotein, serum albumin, Controlling Nutritional Status (CONUT) score and visceral fat area/subcutaneous fat area ratio (VSR). CONCLUSION: A novel random forest model using the clinical and serological parameters of baseline data was established to identify CD patients with baseline inflammation to achieve IFX response. This model could be valuable for physicians, patients and insurers, which allows individualised therapy.

Unexplained ascites caused by myeloid sarcoma with omentum involvement.

Concerning the article published in this journal by Meireles LC et al., we have recently identified a case of myeloid sarcoma involving the omentum, but it was characterized by ascites as the main symptom, not intestinal obstruction.

Development and validation of predictive models for Crohn's disease patients with prothrombotic state: a 6-year clinical analysis.

BACKGROUND: Crohn's disease (CD) is a chronic idiopathic inflammatory disease. Studies show that multiple risk factors during disease progression can lead to a prothrombotic state (PTS), which predisposes the patient to thrombosis. Therefore, predicting PTS can help identify patients at risk of thrombosis. The aim of our study was to classify CD patients through D-dimer levels, and construct a prediction model for PTS. METHODS: The clinical and laboratory data parameters were extracted from a retrospective observational cohort. The factors significantly associated with PTS were determined by univariate analysis, and the importance rankings were calculated. Two multivariate models were then constructed using these factors to predict PTS in CD using logistic regression and random forest analysis. RESULTS: A total of 744 CD patients were included in the study, of which 116 were in PTS. The significant PTS-related factors were older patients, isolated colonic involvement, penetrating behavior, fever symptom, disease activity, abdominal surgery, lymphocyte counts, hematocrit levels, erythrocyte sedimentation rate, C-reactive protein, hematocrit, mean corpuscular volume levels and albumin. Multivariate logistic regression and random forest models predicted PTS with the accuracy of 89.73% and 90.63% respectively, and the corresponding AUC were 0.76 and 0.84. CONCLUSIONS: Two predictive models based on clinical and laboratory variables accurately identified CD patients with PTS with high precision.

Feature-shared adaptive-boost deep learning for invasiveness classification of pulmonary subsolid nodules in CT images.

PURPOSE: In clinical practice, invasiveness is an important reference indicator for differentiating the malignant degree of subsolid pulmonary nodules. These nodules can be classified as atypical adenomatous hyperplasia (AAH), adenocarcinoma in situ (AIS), minimally invasive adenocarcinoma (MIA), or invasive adenocarcinoma (IAC). The automatic determination of a nodule's invasiveness based on chest CT scans can guide treatment planning. However, it is challenging, owing to the insufficiency of training data and their interclass similarity and intraclass variation. To address these challenges, we propose a two-stage deep learning strategy for this task: prior-feature learning followed by adaptive-boost deep learning. METHODS: The adaptive-boost deep learning is proposed to train a strong classifier for invasiveness classification of subsolid nodules in chest CT images, using multiple 3D convolutional neural network (CNN)-based weak classifiers. Because ensembles of multiple deep 3D CNN models have a huge number of parameters and require large computing resources along with more training and testing time, the prior-feature learning is proposed to reduce the computations by sharing the CNN layers between all weak classifiers. Using this strategy, all weak classifiers can be integrated into a single network. RESULTS: Tenfold cross validation of binary classification was conducted on a total of 1357 nodules, including 765 noninvasive (AAH and AIS) and 592 invasive nodules (MIA and IAC). Ablation experimental results indicated that the proposed binary classifier achieved an accuracy of 73.4 \% ± 1.4 with an AUC of 81.3 \% ± 2.2 . These results are superior compared to those achieved by three experienced chest imaging specialists who achieved an accuracy of 69.1 \% , 69.3 \% , and 67.9 \% , respectively. About 200 additional nodules were also collected. These nodules covered 50 cases for each category (AAH, AIS, MIA, and IAC, respectively). Both binary and multiple classifications were performed on these data and the results demonstrated that the proposed method definitely achieves better performance than the performance achieved by nonensemble deep learning methods. CONCLUSIONS: It can be concluded that the proposed adaptive-boost deep learning can significantly improve the performance of invasiveness classification of pulmonary subsolid nodules in CT images, while the prior-feature learning can significantly reduce the total size of deep models. The promising results on clinical data show that the trained models can be used as an effective lung cancer screening tool in hospitals. Moreover, the proposed strategy can be easily extended to other similar classification tasks in 3D medical images.

Flame evolution in shock-accelerated flow under different reactive gas mixture gradients.

The interaction between a planar shock wave and a spherical flame is studied numerically for an ethylene-oxygen-nitrogen gas mixture. Influences of different initial reactive gas mixture gradients on the shock-flame interaction are investigated by using high-resolution computational simulations. The results show that the different reactive gas mixture gradients can greatly affect the flame evolution in shock accelerated flow. A detonation only emerges in the homogenous reactive gas mixture case, but a distinct shock bifurcation can be found in the inhomogeneous cases where the leftward reflected shock wave propagates in a reverse flow with a high transverse velocity gradient in the inhomogeneous cases. Also, the flame volume and heat release rate increase when the distribution of the reactive gas mixture is uniform or with a positive gradient in this paper, but decrease when the distribution of the reactive gas mixture is with a negative gradient, however, the ratio of unburned to burned regions in the flame zone shows just the opposite trends. Furthermore, the factors affecting the vorticity generation are also analyzed. It is found that the compression term has a relatively stronger influence on the vorticity generation in all the three cases except the period before the reflected shock wave impinges on the distorted flame in the homogeneous case, wherein the baroclinic effect dominates the vorticity generation in the flame zone.

Preparation of microwave-activated magnetic bio-char adsorbent and study on removal of elemental mercury from flue gas.

In this study, novel activated magnetic bio-char adsorbents were proposed to remove the element mercury (Hg0) from flue gas. Microwave activation and Mn-Fe mixed oxides impregnation assisted by ultrasound treatment were applied on the modification of renewable cotton straw chars. The influence of different preparation methods, loading value of Mn-Fe, molar ratio of Mn/Fe, calcining temperature, reaction temperature and individual flue gas ingredients (O2, NO, SO2 and H2O) on removal of Hg0 was investigated in a fixed bed system. The characterization results reveal that microwave activation is advantageous for the development of the pore structure, and ultrasound treatment can optimize the dispersion of Mn and Fe active ingredients. MnFe4%(3/10)/CSWU700 adsorbent exhibits the optimal Hg0 removing performance. O2, NO, low concentration of SO2 (<600 ppm) and low concentration of H2O (<2%) are found to be favourable for the capture of Hg0, while high concentrations of SO2 and H2O inhibit the removal of Hg0. Chemical adsorption acts a pivotal part in the process of Hg0 removal. Mn and Fe active ingredients are consumed in large quantities during the Hg0 capture. In addition, chemisorbed oxygen (Oß) also plays an indispensable in the oxidation process of Hg0. Furthermore, the magnetic adsorbent MnFe4%(3/10)/CSWU700 presents a good regeneration performance and adsorption capacity.

Gas-phase elemental mercury removal using ammonium chloride impregnated sargassum chars.

In this article, pyrolyzed bio-chars derived from a kind of macroalgae, sargassum, were modified by ammonium chloride (NH4Cl) impregnation, and were applied to remove Hg0 from flue gas. The characteristics of sorbents were investigated by the Brunauer-Emmett-Teller, X-ray photoelectron spectroscopy, scanning electron microscopy and ultimate and proximate analysis. The key parameters (e.g. loading value, reaction temperature and concentration of O2, NO, SO2 and water vapor), kinetics analysis and reaction mechanism of Hg0 removal were investigated. The results show that increasing loading value, reaction temperature, O2 concentration and NO concentration enhance Hg0 removal. The increase in SO2 concentration or water vapor concentration has a dual effect on Hg0 removal. The C-Cl groups and C=O groups play an important role in the process of Hg0 removal. The Hg0 removal process of modified samples meets the pseudo-second-order kinetic model.

Simultaneous absorption of SO2 and NO from flue gas using ultrasound/Fe2+/heat coactivated persulfate system.

A novel process on simultaneous absorption of SO2 and NO from flue gas using ultrasound (US)/Fe2+/heat coactivated persulfate system was proposed. The influencing factors, active species, products and mechanism of SO2 and NO removal were investigated. The results indicate that US enhances NO removal due to enhancement of mass transfer and chemical reaction. US of 28kHz is more effective than that of 40kHz. NO removal efficiency increases with increasing persulfate concentration, ultrasonic power density and Fe2+ concentration (at high persulfate concentration). Solution pH, solution temperature and Fe2+ concentration (at low persulfate concentration) have double effect on NO removal. SO2 is completely removed in most of tested removal systems, except for using water absorption. US, Fe2+ and heat have a synergistic effect for activating persulfate to produce free radicals, and US/Fe2+/heat coactivated persulfate system achieves the highest NO removal efficiency. ·OH and SO4-· play a leading role for NO oxidation, and persulfate only plays a complementary role for NO oxidation.

The treatment of femoral neck fracture using VEGF-loaded nanographene coated internal fixation screws.

PURPOSE: Previous studies have proved that vascular endothelial growth factor (VEGF) has a dual role in the promotion of new bone formation and blood vessel repair during fracture healing. However, how to introduce VEGF to a fracture site safely and effectively is still a challenge. This study aimed to prepare a VEGF-loaded nanographene coated internal fixation screw and to evaluate its effects in the treatment of femoral neck fracture. METHODS: Nanographene coated screws were prepared by direct liquid-phase exfoliation of the graphite method, and the surface characteristics were observed through scanning electron microscopy (SEM). VEGF was loaded on nanographene coatings through physical adsorption, and the VEGF controlled release was examined by ELISA. Then a canine femoral neck fracture model was built to examine both the angiogenic and osteogenic properties of the VEGF-loaded coated screws. X-ray, micro-CT-based microangiography, and histopathologic evaluation were used to assess the fracture healing progress. RESULTS: The results demonstrated that nanographene could load VEGF effectively, and the accumulative release of VEGF clearly increased during the entire testing period (9 days) without burst release. In canine fracture models, the results of X-ray, microangiography, and histopathologic examination proved that the speed of fracture healing, new bone formation area, and revascularization of the fractured femoral heads in the VEGF-loaded coated screws groups were significantly higher than in the control groups. CONCLUSION: Our study proved that VEGF-loaded nanographene coated screws were effective in the treatment of femoral neck fracture and prevention of avascular necrosis of femoral head.

Plate fixation for Letenneur type I Hoffa fracture: a biomechanical study.

BACKGROUND: A coronal fracture of the posterior femoral condyle, also known as a Hoffa fracture, is an unusual injury, and there are only a handful of case reports or series exploring it. The optimal fixation method of these intraarticular fractures remains controversial; improper or unstable fixation usually lead to an unsatisfactory prognosis. The use of posterior-anterior or reversed lag screw fixation is still a popular method. Additional buttress plating is also recommended for fixation of these difficult fractures. The purpose of this study was to compare the mechanical strength of four different fixation patterns for this uncommon fracture. MATERIAL AND METHODS: Sixteen sawbone simulated models of Letenneur type I Hoffa fractures were created with one of four fixation patterns: two screws implanted in the anterior-posterior (AP) direction or posterior-anterior (PA) direction; one screw in the PA direction with a plate implanted in the posterior position of the distal femoral condyle or with a plate in the lateral position. Biomechanical testing was performed to determine the post-fixation axial stiffness, the maximum load to failure and the fragment vertical displacement for each of the four constructs. RESULTS: The plate fixation patterns whether implanted in the posterior or lateral position were shown to provide higher overall axial stiffness and load to failure, and less vertical displacement than the other two patterns of pure screw fixation. Among these constructs, the lateral plate fixation was found to provide the highest stiffness and load to failure and the least displacement for the posterior condylar fragments, followed by the posterior plate fixation. The lowest overall stiffness and load to failure and the largest vertical displacement were found in the construct with the AP direction placed screws. CONCLUSION: It was concluded that the lateral position implanted plate is biomechanically the strongest fixation method for Letenneur type I Hoffa fractures. However, this plate fixation is not recommended for all cases. The choice of internal fixation pattern depends on the surgeons.

Removal of elemental Mercury from flue gas using wheat straw chars modified by K2FeO4 reagent.

In this article, wheat straw (WS) char, a common agricultural waste and renewable biomass, was pyrolyzed and then modified by K2FeO4 reagent to develop an efficient sorbent for removal of Hg0 from flue gas. Brunauer-Emmett-Teller, scanning electron microscopy with energy spectrum and X-ray diffraction (XRD) were employed to characterize the sorbents. The effects of K2FeO4 loading, reaction temperature, Hg0 inlet concentration and concentrations of gas mixtures O2, NO and SO2 in flue gas on Hg0 removal were investigated in a fixed-bed reactor. The results show that K2FeO4-impregnation can improve pore structure of WS char and produce new active sites, which significantly enhance Hg0 removal. Increasing Hg0 inlet concentration significantly decreases Hg0 removal efficiency. O2 in flue gas promotes Hg0 oxidation by replenishing the oxygen groups on the surface of modified chars. The presence of NO obviously promotes Hg0 removal since it can oxidize Hg0 to Hg(NO3)2. SO2 in flue gas significantly decreases Hg0 removal efficiency due to the competition adsorption between SO2 and Hg0. The increase in reaction temperature has a dual impact on Hg0 removal.

Minimally invasive pedicle screw fixation combined with percutaneous vertebroplasty for the treatment of thoracolumbar burst fracture.

INTRODUCTION: To evaluate the feasibility, efficacy and safety of minimally invasive pedicle screw fixation (MIPS) combined with percutaneous vertebroplasty (PVP) using calcium phosphate for the treatment of thoracolumbar burst fracture without neurologic deficits. METHODS: Between September 2011 and April 2013, a total of thirty-seven patients with a mean age of 50.73 years (range 40-63 years), who suffered from thoracic or lumbar burst fracture without neurologic deficits underwent the procedure of MIPS combined with PVP using calcium phosphate. The preoperative and postoperative pain assessment were evaluated using Visual Analogue Scale (VAS) and American Spinal Injury Association (ASIA). The Cobb angles and central and anterior columns height were measured on the lateral radiographs before surgery and immediately, 1 month, 3 months, 6 months, 1 year and 2 years after surgery. RESULTS: The patients were followed up for an average of 27.54 ± 2.47 months. The mean VAS significantly decreased from 9 (range 6-10) before surgery 2 (range 1-3) immediately after surgery and 1 (range 0-2) at 2-year follow-up. The Cobb angle was 22.58 ± 1.70° before surgery and 4.11 ± 1.41° immediately after surgery and 5.06 ± 1.11° at 2-year follow-up. The central and anterior vertebral body height decreased from 44.10 ± 7.0% and 49.76 ± 6.43% before surgery to 80.09 ± 4.05% and 93.31 ± 1.87% immediately after surgery, respectively. No significant changes in vertebral body height restoration were observed during 2 years follow-up after surgery. In addition, there were no instrumentation failure and complications in all patients. CONCLUSIONS: Our study indicated that MIPS combined with PVP using calcium phosphate is a good choice for the treatment of thoracolumbar burst fracture without neurologic deficits.