Design of organic structure directing agents to guide the synthesis of zeolites for the separation of ethylene–ethane mixtures

Industrial production of ethylene entails a costly separation from the ethane by-product, and this separation is the dominant consumer of energy in the process. Zeolites have been proposed as a next generation material for this separation process, and a molecular screen of all known zeolites has revealed several promising candidate materials. None of the identified materials has yet been synthesized in the all-silica form evaluated in the screen. We here design organic structure directing agents (OSDAs) for four of the zeolites with the best predicted separation performance, two that are ethylene selective and two that are ethane selective. The designed OSDAs may enable the synthesis of these zeolites for more energy efficient separation of ethylene and ethane.

Structure directing agents were designed in this work to aid in the synthesis of four zeolites predicted to efficiently separate ethane and ethylene.     

Soluble mannosylated myelin peptide inhibits the encephalitogenicity of autoreactive T cells during experimental autoimmune encephalomyelitis

We have previously shown that immunization with a mannosylated myelin peptide in complete adjuvant induces tolerance instead of disease in experimental autoimmune encephalomyelitis (EAE), a rodent model for multiple sclerosis. In this report we demonstrate that treatment with a soluble mannosylated epitope of proteolipid protein (M-PLP(139-151)) significantly inhibits disease mediated by autoreactive myelin-specific T cells during EAE. Treatment with M-PLP(139-151), applied in different EAE models, significantly reduced the incidence of disease and the severity of clinical symptoms. Delayed-type hypersensitivity responses were abolished after peptide treatment, emphasizing the impact on peripheral T-cell reactivity. Histological analysis of spinal cord tissue from mice treated with M-PLP(139-151) revealed the presence of only few macrophages and T cells. Moreover, little expression of interferon-gamma, interleukin-23, or major histocompatibility complex class II antigen was detected. Immune modulation by M-PLP(139-151) was primarily antigen-specific because an irrelevant mannosylated peptide showed no significant effect on delayed-type hypersensitivity responses or on the course of EAE. Therefore, mannosylated antigens may represent a novel therapeutic approach for antigen-specific modulation of autoreactive T cells in vivo.     

Quilting Prevents Seroma Formation Following Breast Cancer Surgery: Closing the Dead Space by Quilting Prevents Seroma Following Axillary Lymph Node Dissection and Mastectomy

Background

Seroma is a frequent problem after mastectomy (ME) and axillary lymph node dissection (ALND). Seroma is associated with pain, discomfort, impaired mobilisation and repeated aspirations, often resulting in a surgical site infection (SSI). It has already been demonstrated that minimizing dead space through fixation of the skin flaps to the underlying muscles (quilting) lowers the incidence of seroma. The aim of this study was to evaluate the effect of quilting on the incidence of seroma, and SSI.

Methods

Two consecutive groups with a total of 176 patients following ME and/or ALND were retrospectively compared. Endpoints were the incidence of seroma, and number and volume of aspirations and SSIs. Analysed risk factors were age, ME, lymph node dissection, neoadjuvant therapy, body mass index (BMI) and hypertension.

Results

The quilted group (n = 89) scored significantly better on all endpoints compared with the conventional group (n = 87). The incidence of seroma decreased from 80.5 % to 22.5 % (p < 0.01), the mean number of aspirations from 4.86 to 2.40 (p = 0.015), the volume of aspirations from 1660 ml to 611 ml (p = 0.05) and the SSIs from 31.0 % to 11.2 % (p < 0.01). Increasing age and lymph node dissection were found to be risk factors for seroma; quilting was a protective factor.

Conclusion

Quilting is an effective method for preventing seroma and its complications.     

Virulence factors of Escherichia coli in urinary isolates from pregnant women

Urinary isolates from 24 pregnant women with acute pyelonephritis and from 37 pregnant women with bacteriuria detected at screening were characterized for O:K:H serotype, electrophoretic type, adherence, hemolysin production, and serum resistance. Between the two diagnostic groups, only three clones were identical. For the remaining isolates, both the identification markers and virulence traits differed significantly. The strains from pregnant women with pyelonephritis did not significantly differ from those from non-pregnant women. Thus, pregnancy was shown not to abolish the difference in virulence between Escherichia coli causing acute pyelonephritis and asymptomatic bacteriuria.     

Hemodynamic comparison of different multisites and multipoint pacing strategies in cardiac resynchronization therapies

Purpose

Late cure after a previously failed ablation of ventricular arrhythmias (VAs) is a relatively common phenomenon. The present study sought to delineate the incidence and electrophysiological characteristics of late cure in idiopathic VA patients.

Methods

Totally, 45 idiopathic VA cases (mean age 44?±?18 years, 27 males) either failed acutely or recurred within 12 h were enrolled in this study. Based on intensive clinical observations in the acute period, 19 (42%) patients demonstrated late cure in the first week after the procedure.

Results

The late cure patients had significantly better acute and cumulative ablation effects during the procedure than did those without a late cure. Additionally, they had a prediction that originated from the right ventricular outflow tract, aortic-mitral continuum, and left summit area relative to other sites (13/18 vs 6/27, p?<?0.01). In a median follow-up of 24 [14, 46] months, 7/19 (37%) patients had their VAs recurred. The late cure group had significantly more patients cured at long-term follow-up than those without (12/19 vs 0/26, p?<?0.01). A cutoff value of the “time to eliminate VAs” >?7.0 s was able to predict a long-term recurrence of the VAs with 62.5% sensitivity and 85.7% specificity.

Conclusions

The late cure of VAs occurs in more than one third of patients who have a seemingly unsuccessful ablation session, which is clustered in the first week after the procedure. However, long-term recurrence of VAs occurred in 37% of the late cure patients, emphasizing the importance of long-term follow-up.

     

Relation between abnormal ventricular impulse conduction and heart failure

Ventricular pacing and left bundle branch block (LBBB) are two of the most common causes of asynchronous electrical activation of the ventricles. The sequence of activation is an important determinant of cardiac pump function. The sequence of activation during LBBB and during pacing at the conventional pacing site, the RV apex, is similar. In this article the literature on the effect of RV pacing and LBBB on regional and global LV pump function, on long-term adaptations (remodeling) and on their possible contribution to the development of heart failure is discussed. Evidence is increasing that asynchronous electrical activation contributes significantly to the development of heart failure.     

Muscle MRI in patients with long-chain fatty acid oxidation disorders

Introduction

Muscle magnetic resonance imaging (MRI) is a useful tool for visualizing abnormalities in neuromuscular disorders. The value of muscle MRI has not been studied in long-chain fatty acid oxidation (lcFAO) disorders. LcFAO disorders may present with metabolic myopathy including episodic rhabdomyolysis.

Objective

To investigate whether lcFAO disorders are associated with muscle MRI abnormalities.

Methods

Lower body MRI was performed in 20 patients with lcFAO disorders, i.e. three carnitine palmitoyltransferase 2 deficiency (CPT2D), 12 very long-chain acyl-CoA dehydrogenase deficiency (VLCADD), three mitochondrial trifunctional protein deficiency (MTPD) and two isolated long-chain hydroxyacyl-CoA dehydrogenase deficiency (LCHADD).

Results

At the time of MRI, four patients had muscle weakness, 14 had muscle pain and 13 were exercise intolerant. Median creatine kinase (CK) level of patients at the day of MRI was 398 U/L (range 35-12,483). T1W and STIR signal intensity (SI) were markedly increased in MTPD patients from girdle to lower leg. VLCADD patients showed predominantly proximal T1W SI changes, whereas LCHADD patients mostly showed distal T1W SI changes. Prominent STIR weighted signal intensity increases of almost all muscle groups were observed in patients with VLCADD and LCHADD with very high CK (>11.000) levels.

Conclusions and relevance

lcFAO disorders are associated with specific patterns of increased T1W and STIR signal intensity. These patterns may reflect lipid accumulation and inflammation secondary to lcFAO defects and progressive muscle damage. Future studies are needed to investigate whether muscle MRI might be a useful tool to monitor disease course and to study pathogenesis of lcFAO related myopathy.     

Massive weight loss after bariatric surgery and the demand (desire) for body contouring surgery

Background

Massive weight loss after bariatric surgery can cause physical, functional, hygienic, and psychological problems and can also have impact on the quality of life. Reconstructive body contouring surgery can provide a solution for these problems. The number of patients seeking contouring surgery is far greater than the actual number of surgical reconstructions performed. The aim of this study was to register the demand for reconstructive surgery, take an inventory of the complaints, and index body satisfaction after massive weight loss.

Methods

This retrospective study is based on questionnaires filled out by 237 patients between 2007 and 2010 after undergoing a primary laparoscopic Roux-en-Y gastric bypass.

Results

This study showed a desire for reconstructive plastic surgery after massive weight loss in 28.3 % of the patients. These patients can in turn be divided into patients who received surgery (6.8 %), patients on the waiting list (5.5 %), and patients rejected by their insurance company (16 %). Ninety percent of these patients reported functional problems caused by excess skin, and 52 % experienced psychological distress after the massive weight loss. Patients were bothered most by their abdomen and breasts. Men were generally more satisfied than women (50 and 41 %, respectively).

Conclusions

Body contouring surgery reduces physical and psychological complaints after massive weight loss and positively influences quality of life. Prospective studies are needed to evaluate the approval and rejection criteria of health-care insurance companies. Level of evidence: III, risk/prognostic study