Emission characteristics of condensable particulate matter (CPM) from FCC flue gas.

Particulate matter (PM) as a major air pollutant, generally includes filterable particulate matter (FPM) and condensable particulate matter (CPM). CPM has gradually attracted widespread attention recently, due to its increasing proportion in total PM emissions. Fluid catalytic cracking (FCC) units, the main emission source in refineries, mostly use wet flue gas desulfurization (WFGD), which will produce a large amount of CPM. However, CPM emission and composition of FCC units are actually unclear. In this work, we aimed to understand the emission characteristics of CPM in FCC flue gas and provide some potential control strategies. Here, the stack tests of three typical FCC units were conducted to monitor FPM and CPM, and the field monitoring FPM results are higher than the concentration provided by Continuous Emission Monitoring System (CEMS). The emission of CPM is at a high-level concentration from 28.88 to 86.17 mg/Nm3, divided into inorganic fraction and organic fraction. The inorganic fraction is mainly composed in CPM, where water-soluble ions including SO42-, Na+, NH4+, NO3-, CN-, Cl-, and F-, are the major contributors. Moreover, a variety of organic compounds are detected as qualitative analysis of organic fraction in CPM, which can be roughly classified into alkanes, esters, aromatics, and others. Finally, on the basis of the understanding of the characteristics of CPM, we have proposed two strategies for CPM control. This work is expected to advance CPM emission regulation and control in FCC units.

Characterization of Pediatric Extension Trigger Thumb: An Insight Into a Rare Manifestation From a Single-Center Retrospective Cohort Analysis.

PURPOSE: This study aimed to evaluate the clinical features, possible etiology, and surgical outcomes of a rare manifestation of pediatric trigger thumb, extension trigger thumb (ETT). METHODS: We retrospectively reviewed a database of surgically treated trigger thumb patients and identified patients with ETT who had a minimum of 1-year follow-up after surgery from 2012 to 2018. We reviewed demographic and clinical information and recorded active and passive interphalangeal (IP) joint flexion before, during (intraoperative simulated active flexion), and after surgery (at final follow-up). These measurements were compared with those obtained from the unaffected thumb in unilaterally affected patients. RESULTS: Eighteen patients with ETT (21 affected thumbs) were identified. The incidence of ETT was 1%, with an increasing incidence through the years of the study. We found that 14 of 18 ETT patients had a history of fixed flexion trigger thumb managed with nonsurgical treatment. There was an average 38° ± 10° improvement in active IP joint flexion after surgery and at the final follow-up. For unilaterally affected patients, active IP joint flexion improved but did not reach the same level as on the unaffected side. CONCLUSIONS: Extension trigger thumb is a rare manifestation with a low incidence in pediatric trigger thumbs. Surgical release of the A1 pulley achieves a moderate improvement in flexion function at the IP joint. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic IV.

Clinical Characteristics and Surgical Outcomes of Congenital Ulnar-deviated Thumbs: Delta Triphalangeal Thumbs and Irregular Epiphyses.

BACKGROUND: Delta triphalangeal thumbs (DTPT) and irregular epiphysis thumbs (IET) had different anatomic deformities. Our primary purpose was to evaluate the clinical and radiographic outcomes of surgical treatment in DTPT and IET. METHODS: In total, 43 ulnar-deviated thumbs were included and categorized into 2 types according to x-ray and exploration during surgery, DTPT and IET. Surgical excision of the delta phalanx in DTPT and intraepiphysis osteotomy in IET was conducted. RESULTS: In total, 23 ulnar-deviated thumbs were classified as DTPT and 20 as IET. Ten thumbs that could not be classified initially were followed-up until they could be categorized at the mean age of 24 months. The preoperative mean degrees of ulnar deviation at the interphalangeal joints were 40 and 33 degrees, in DTPT and IET, respectively. The mean degrees were 2 and 5 degrees in final follow-up, showing significant improvement (DTPT, P<0.05; IET, P<0.05). Complications during the study included residual ulnar deviation, overcorrection, and nonunion. The stability and range of movement at the interphalangeal joint were good overall. According to the Japanese Society for Surgery of the Hand scoring system, results were excellent in 29 cases, good in 13, and fair in 1. CONCLUSIONS: Ulnar clinodactyly of the thumb occurs because of different anatomic features such as DTPT or IET. We recommend surgical treatment be postponed until the anatomic abnormality can be ascertained. Furthermore, almost all patients with ulnar-deviated thumbs had significant improvement in clinical and radiographic outcomes after surgery.

Identification of risk factors affecting bone formation in gradual ulnar lengthening in children with hereditary multiple exostoses: A retrospective study.

The forearm deformity classified by Masada is a characteristic trait of patients with hereditary multiple exostoses (HME). Ulnar gradual lengthening, which was considered to be a safe and reliable procedure, was popular in treating these difficult deformities, however, delayed consolidation of the callus is uncommon but not rare in literature review. The purpose of this study was to try to identify the risk factors influencing bone healing in gradual ulnar lengthening in HME.We retrospectively reviewed patients with HME-induced forearm deformity who underwent gradual ulnar lengthening at our hospital from 2010 to 2016. Patients' demographic data, forearm deformity of Masada type, surgical procedure, ulnar diameter of osteotomy site, and external fixator type were recorded. We also reviewed radiographical data included gained length, axis deviation, callus form. Clinical outcome was assessed by the bone healing index (HI). Multiple linear regression was used to analyze the relationships between diffident parameters and the HI, the level of significance was set P <.05.Thirty-three patients were included in this study. The mean follow-up period was 1.5 (range 0.5-8) years. Circular external fixators were used in 5 patients and monolateral external fixators were used in 28 patients. The mean achieved length was 4.24 cm. The mean HI was 50.3 (range 26.6-99.3) days/cm. In patient with monolateral external fixator, patient's age was positively correlated with the bone HI (P = .001), while diameter and body mass index (BMI) were negatively correlated with the HI (P = .040, .018, respectively). Patient's sex, removal of distal ulnar exostoses, lengthening percentage, and axis deviation were non-significant in the regression model.When using monolateral external fixator for ulnar lengthening, patient's age, diameter of osteotomy site, and BMI are the most important risk factors related to bone formation. Pediatric orthopedic surgeons should consider these variables in order to avoid delayed union.

Risk factors for refracture of the forearm in children treated with elastic stable intramedullary nailing.

PURPOSE: This study aims to investigate risk factors for refracture of the forearm in children treated with elastic stable intramedullary nailing (ESIN). METHODS: Clinical data of 267 patients who had been treated for forearm fractures by ESIN in our hospital from January 2010 to December 2014 were retrospectively reviewed. Risk factors for forearm refractures were determined using logistic regression analysis. RESULTS: Forearm refractures occurred in 11 children. Univariate analysis revealed that age, body weight, number of fractures, open fracture, nail diameter, and immobilization time were not associated with refractures. However, gender (male, P = 0.042) and fracture location (lower third, P = 0.007) were significantly associated with refractures. Multivariate analysis revealed that fracture location was an independent risk factor for forearm refractures (P = 0.031). CONCLUSION: Forearm refracture is uncommon in children treated with ESIN. Fracture location is an independent risk factor for forearm refractures in these patients.

Heterogeneous spectrum of EXT gene mutations in Chinese patients with hereditary multiple osteochondromas.

Hereditary multiple osteochondroma (HMO) is one of the most common genetic skeletal disorders. It is caused by mutations in either EXT1 or EXT2 resulting in abnormal skeletal growth and morphogenesis. However, the spectrum and frequency of EXT1 and EXT2 mutations in Chinese patients with HMO was not previously investigated.Mutations were identified by performing Sanger sequencing analysis of the complete coding regions and flanking intronic sequences of EXT1 and EXT2, followed by multiplex ligation-dependent probe amplification (MLPA) analysis to detect gene deletions or duplications that could not be identified by the Sanger sequencing method.The present study identified pathogenic mutations in 93% (68/73) of unrelated HMO probands from 73 pedigrees. Mutations in EXT1 and EXT2 were identified in 53% (39/73) and 40% (29/73) of families. We identified 58 distinct mutations in EXT1 and EXT2, including 20 frameshift mutations, 16 nonsense mutations, 7 missense mutations, 9 splice site mutations, 5 large deletions, and 1 in-frame deletion mutation. Twenty-six of these mutations were novel and 32 were previously reported. Most of the mutations in EXT1 were base deletions or insertions (21/33), whereas the majority of those in EXT2 were single base substitution (18/25).Complete sequencing of both the EXT1 and EXT2 followed by MLPA analysis is recommended for genetic analysis of Chinese patients with HMO. This study provides a comprehensive characterization of the genetic aberrations found in Chinese patients with HMO and highlights the diagnostic value of molecular genetic analysis in this particular disease.

Soft tissue Rosai-Dorfman disease in child: A case report and literature review.

BACKGROUND: Rosai-Dorfman disease was commonly characterized as massive, painless, bilateral, symmetric cervical lymphadenopathy, with fever, leukocytosis, and elevated sedimentation rate. However, soft tissue Rosai-Dorfman disease (STRDD) is a rare benign tumor. METHODS: We hereby present 1 case of a 17-month-old girl, an isolated subcutaneous mass was detected on her right forearm, and no signs of pain, swelling, or erythema were observed at the site. RESULTS: The patient underwent an excisional biopsy for the mass. Immunohistochemistry results showed that it was positive for S-100 protein and CD68, whereas negative for CD1a, which supported the diagnosis of STRDD. CONCLUSIONS: The patient showed no evidence of recurrence or metastasis 2 years after the surgery.Some multifocal masses were reported to be much more prone to recurrence. Further follow-up of STRDD is necessary.

Tracheobronchial reconstructions with bronchoplastic closure: an alternative method in treatment of bronchogenic carcinoma involving the carina or tracheobronchial angle.

OBJECTIVE: Our objective was to summarize our experience with tracheobronchial reconstructions using bronchoplastic closure for airway defects after noncircumferential resections of bronchogenic carcinoma involving the carina or tracheobronchial angle. METHODS: From January 1990 to December 2005, all patients who underwent tracheobronchial reconstructions with bronchoplastic closure for bronchogenic carcinoma involving the carina or tracheobronchial angle were included. The clinical data for patients were collected retrospectively, including demographic characteristics, occurrences of postoperative complications, and survival. RESULTS: A total of 40 patients were eligible, including 23 who had right pneumonectomies, 6 who had right upper lobectomies, and 11 who had left pneumonectomies, associated with lower lateral wall of the trachea resections or with partial carinal resections for centrally localized tumors. The airway defects ranged from 0.5×2 cm to 2×4 cm and involved up to 50% of the airway circumference. Microscopic residual disease was found postoperatively at the bronchial margin in 20% (8/40). Of 40 patients, 2 (5.0%) had pulmonary atelectasis develop, 2 (5.0%) arrhythmia, 2 (5.0%) bronchopleural fistula, and 1 (2.5%) airway stenosis after operation. Thirty-day mortality was 2.5% (1/40). Median survival for 40 patients was 18.5 months with a cumulative survival of 72.2%, 26.6%, and 21.3% at 1, 3, and 5 years, respectively. CONCLUSIONS: Tracheobronchial reconstruction using bronchoplastic closure might be a reasonable option for closing massive central airway defects for advanced bronchogenic carcinoma involving the tracheobronchial angle or carina, avoiding tracheal sleeve pneumonectomy with limited excision of the lateral wall of the trachea or carina.

Benign clear cell tumor of the lung.

Clear cell tumor of the lung is a rare benign tumor. Herein, we present a case of a 51-year-old man who had an abnormal pulmonary nodule occasionally found on chest roentgenogram. A computed tomographic scan showed a solitary nodule (approximately 15 mm in diameter) in the lingular segment of the left upper lobe. The patient underwent a lobectomy for the tumor. The pathologic report supported the diagnosis of clear cell tumor of the lung. The patient showed no evidence of recurrence or metastasis 2 years postoperatively.