Bio-cleaning improves the mechanical properties of lignin-based carbon fibers

Production of carbon fibers (CF) using renewable precursors has gained importance particularly in the last decade to reduce the dependency on conventional petroleum-based precursors. However, pre-treatment of these renewable precursors is still similar to that of conventional ones. Little work is put into greener pre-treatments and their effects on the end products. This work focuses on the use of bio-cleaned lignin as a green precursor to produce CF by electrospinning. Bio-cleaned kraft lignin A (Bio-KLA) and uncleaned kraft lignin A (KLA) were used to explore the effect of bio-cleaning on the diameter and mechanical properties of lignin fibers and CF. The effect of electric field, lignin-to-poly(ethylene oxide) (PEO) ratio and PEO molecular weight (MW) were evaluated by 3³ factorial design using Design of Experiment (DOE). The electrospinning process parameters were optimized to obtain a balance between high elastic modulus and small fiber diameter. The model predicted optimized conditions were 50 kV m⁻¹ electric field, 95/5 lignin-to-PEO ratio and 1000 kDa MW of PEO. When compared to KLA, Bio-KLA CFs showed a 2.7-fold increase in elastic modulus, 2-fold increase in tensile strength and 30% decrease in fiber diameter under the same optimum conditions. The results clearly show that bio-cleaning improved the mechanical properties of lignin derived CF.

Waste lignin (KLA) and bio-cleaned lignin (Bio-KLA) precursors, used to produce parameter-optimized-electrospun carbon fibers showed improved mechanical properties for Bio-KLA.     

Post-mastectomy reconstruction: A risk-stratified comparative analysis of outcomes

IntroductionAlthough breast reconstruction following mastectomy plays a role in the psychological impact of breast cancer, only one in three women undergo reconstruction. Few multi-institutional studies have compared complication profiles of reconstructive patients to non-reconstructive.MethodsUsing the National Surgical Quality Improvement database, all patients undergoing mastectomy from 2006 to 2010, with or without reconstruction, were identified and risk-stratified using propensity scored quintiles. The incidence of complications and comorbidities were compared.ResultsOf 37,723 mastectomies identified, 30% received immediate breast reconstruction. After quintile matching for comorbidities, complications rates between reconstructive and non-reconstructives were similar. This trend was echoed across all quintiles, except in the sub-group with highest comorbidities. Here, the reconstructive patients had significantly more complications than the non-reconstructive (22.8% versus 7.0%, p < 0.001).ConclusionImmediate breast reconstruction is a well-tolerated surgical procedure. However, in patients with high comorbidities, surgeons must carefully counterbalance surgical risks with psychosocial benefits to maximize patient outcomes.Level of evidenceLevel 3     

Carcinosarcoma of esophagus—a case report and review of literature

Carcinosarcoma of esophagus contains both the carcinomatous and sarcomatous elements. These are rare polypoidal malignancies of esophagus. One such case is presented and available literature is reviewed.     

Clinical profile and follow-up of 51 pediatric neurocysticercosis cases: A study from Eastern India

Introduction:

Our present observational study attempted to evaluate the clinical profiles, diagnosis, treatment and follow-up results of 51 pediatric neurocysticercosis patients over a mean duration of five years (from January 2006 to December 2010).

Materials and Methods:

Diagnosis was mainly based on clinical features, computed tomography (CT)/magnetic resonance imaging scan and exclusion of other causes. Patients with active, transitional cysts and seizure were treated with albendazole for 28 days, steroids and anticonvulsants.

Results:

A total of 38 patients completed this study. Mean age of the presentation was 8.47 ± 3.19 years 52.6% of the patients were female. Overall patients presented with generalized seizure in 55.3%, focal in 31.6%, headache ± vomiting in 63.2%, focal neurodeficit in 10.5% and combination of symptoms in 60.5% cases. Contrast CT brain showed a solitary lesion in 27 (71.1%) and multiple in the rest. At presentation lesions were transitional in 58.2%, inactive in 20% and mixed in 14.6%. After a mean of 2 years, seizure persisted in 9 (23.7%) and headache in 8 (21.1%) of whom six had normal electroencephalography (EEG) while one each showed focal slowing, generalized slowing and epileptiform discharges. During the follow-up, CT scan brain 44.7% lesions calcified, 31.6% disappeared, 10.5% regressed and the rest persisted.

Conclusion:

Solitary ring enhancing lesions (transitional stage) involving the parietal lobe was the commonest CT picture at presentation. Generalized tonic-clonic seizure was the most common type of seizure. Number of lesions, persistence of lesion, number of seizures, EEG abnormality at presentation were not found to be prognostically significant (P > 0.05).Key Words: Brain, epilepsy, lesion, neurocysticercosis, parenchyma, solitary     

Variable selection for discrete survival model with frailty in presence of left truncation and right censoring: Studying association of environmental toxicants on time-to-pregnancy

Understanding the association between mixtures of environmental toxicants and time-to-pregnancy (TTP) is an important scientific question as sufficient evidence has emerged about the impact of individual toxicants on reproductive health and that individuals are exposed to a whole host of toxicants rather than an individual toxicant. Assessing mixtures of chemical effects on TTP poses significant statistical challenges, namely (i) TTP being a discrete survival outcome, typically subject to left truncation and right censoring, (ii) chemical exposures being strongly correlated, (iii) appropriate transformation to account for some lipid-binding chemicals, (iv) non-linear effects of some chemicals, and (v) high percentage of concentration below the limit of detection (LOD) for some chemicals. We propose a discrete frailty modeling framework (named Discnet) that allows selection of correlated covariates while appropriately addressing the methodological issues mentioned above. Discnet is shown to have better and stable false negative and false positive rates compared to alternative methods in various simulation settings. We did a detailed analysis of the pre-conception endocrine disrupting chemicals and TTP from the LIFE study and found that older females, female exposure to cotinine (smoking), DDT conferred a delay in getting pregnant, which was consistent across various approaches to account for LOD as well as non-linear associations.     

Endodermal sinus tumour of stomach--a case report

This is a case report of an endodermal sinus tumour arising in the stomach of a 1 1/2 years male child. The tumour occupied full thickness of fundus and part of the body of the stomach. H&E sections of the tumour tissue showed endodermal sinus tumour with predominantly reticular and endodermal sinus patterns. Elevated level of alpha-fetoprotien was detected in the serum of the patient and within the tumour tissue by immunohistochemical technique.     

Disseminated nodular granulomatous perifolliculitis

Nodular granulomatous perifolliculitis is a well-recognized infection of the dermal and subcutaneous tissue caused by dermatophytes, which normally do not invade beyond the epidermis. We report here one such case that occurred in an immunosuppressed individual. The patient was a 35-year-old farmer who presented with small pruritic eruption that had initially appeared on the lower leg and then had gradually spread to hair-bearing areas of the body, finally producing nodular and pustular inflammatory lesions with exacerbations and remissions. Fungal examination by direct potassium hydroxide mount and culture revealed Trichophyton rubrum. Granulomatous changes were seen on histopathological examination. The patient completely responded to systemic antifungal therapy.     

A Bio-Inspired Multi-Population-Based Adaptive Backtracking Search Algorithm

Cognitive Computation - Backtracking search algorithm (BSA) is a nature-based optimization technique extensively used to solve various real-world global optimization problems for the past few...