A Study of the Reinforcement Effect of MWCNTs onto Polyimide Flat Sheet Membranes

Polyimides rank among the most heat-resistant polymers and find application in a variety of fields, including transportation, electronics, and membrane technology. The aim of this work is to study the structural, thermal, mechanical, and gas permeation properties of polyimide based nanocomposite membranes in flat sheet configuration. For this purpose, numerous advanced techniques such as atomic force microscopy (AFM), SEM, TEM, TGA, FT-IR, tensile strength, elongation test, and gas permeability measurements were carried out. In particular, BTDA–TDI/MDI (P84) co-polyimide was used as the matrix of the studied membranes, whereas multi-wall carbon nanotubes were employed as filler material at concentrations of up to 5 wt.% All studied films were prepared by the dry-cast process resulting in non-porous films of about 30–50 μm of thickness. An optimum filler concentration of 2 wt.% was estimated. At this concentration, both thermal and mechanical properties of the prepared membranes were improved, and the highest gas permeability values were also obtained. Finally, gas permeability experiments were carried out at 25, 50, and 100 ◦C with seven different pure gases. The results revealed that the uniform carbon nanotubes dispersion lead to enhanced gas permeation properties

Gigantic hepatic amebic abscess presenting as acute abdomen: a case report

<p>Abstract</p> <p>Introduction</p> <p>Amebiasis is a parasitic disease caused by <it>Entamoeba histolytica</it>. It most commonly results in asymptomatic colonization of the gastrointestinal tract, but some patients develop intestinal invasive or extra-intestinal diseases. Liver abscess is the most common extra-intestinal manifestation. The large number of clinical presentations of amebic liver abscess makes the diagnosis very challenging in non-endemic countries. Late diagnosis of the amebic abscess may lead to perforation and amebic peritonitis, resulting in high mortality rates.</p> <p>Case presentation</p> <p>This report describes a 37-year-old white man, suffering from hepatitis B, with a gigantic amebic liver abscess presenting as an acute abdomen due to its rupture. Rapid deterioration of the patient's condition and acute abdomen led to an emergency operation. A large volume of free fluid together with debris was found at the moment of entry into the peritoneal cavity because of a rupture of the hepatic abscess at the position of the segment VIII. Surgical drainage of the hepatic abscess was performed; two wide drains were placed in the remaining hepatic cavities and one on the right hemithorax. The patient was hospitalized in the ICU for 14 days and for another 14 days in our department. The diagnosis of amebic abscess was made by the pathologists who identified <it>E. histolytica </it>in the debris.</p> <p>Conclusion</p> <p>Acute abdomen due to a ruptured amebic liver abscess is extremely rare in western countries where the parasite is not endemic. Prompt diagnosis and treatment are fundamental to preserving the patient's life since the mortality rates remain extremely high when untreated, even nowadays.</p

Synergistic and competitive aspects of the adsorption of Poly(ethylene glycol) and Poly(vinyl alcohol) onto Na-Bentonite

Graph Presented) The competitive adsorption of poly(ethylene glycol) (PEG) and poly(vinyl alcohol) (PVOH) onto Na-bentonite has been assessed quantitatively. Particular emphasis was focused on the amount of organic located within the bentonite interlayer and any subsequent eff ects on the extent of layer expansion. The individual isotherms showed strong adsorption for both PVOH and PEG at amounts lower than the quantities required to produce a fully loaded bilayer (0.33 g of PVOH/g of clay) and single layered structures (0.10 g of PEG/g of clay), respectively. Above these concentrations, the incremental amounts adsorbed were smaller, and the concentration of adsorbates in solution gradually increased. Na-bentonite adsorbed more PVOH than PEG at any given concentration. In the competitive study, the amount of PVOH adsorbed was enhanced in the presence of PEG (0.10 and 0.30 g/g of clay), but less PEG was adsorbed. At low loadings of PVOH (0.02-0.10 g/g of clay), the amount of adsorbed PEG was increased but at higher PVOH levels PEG adsorption was reduced. The XRD data showed stepped changes in the d-spacing as the adsorbed amounts of both PEG and PVOH increased. The PEG-bentonite samples did not expand beyond a bilayer structure (18 A˚), but the XRD data for PVOH-treated samples indicated the formation of multilayer structures (d ≥ 44 A˚)

Umbilical endosalpingiosis: a case report

<p>Abstract</p> <p>Introduction</p> <p>Endosalpingiosis describes the ectopic growth of Fallopian tube epithelium. Pathology confirms the presence of a tube-like epithelium containing three types of cells: ciliated, columnar cells; non-ciliated, columnar secretory mucous cells; and intercalary cells.</p> <p>We report the case of a woman with umbilical endosalpingiosis and examine the nature and characteristics of cutaneous endosalpingiosis by reviewing and combining the other four cases existing in the international literature.</p> <p>Case presentation</p> <p>A 50-year-old Caucasian, Greek woman presented with a pale brown nodule in her umbilicus. The nodule was asymptomatic, with no cyclical discomfort or variation in size. Her personal medical, surgical and gynecologic history was uneventful. An excision within healthy margins was performed under local anesthesia. A cystic formation measuring 2.7×1.7×1 cm was removed. Histological examination confirmed umbilical endosalpingiosis.</p> <p>Conclusions</p> <p>Umbilical endosalpingiosis is a very rare manifestation of the non-neoplasmatic disorders of the Müllerian system. It appears with cyclic symptoms of pain and swelling of the umbilicus, but not always. The disease is diagnosed using pathologic findings and surgical excision is the definitive treatment.</p

Recent advances and perspectives on starch nanocomposites for packaging applications

Starch nanocomposites are popular and abundant materials in packaging sectors. The aim of this work is to review some of the most popular starch nanocomposite systems that have been used nowadays. Due to a wide range of applicable reinforcements, nanocomposite systems are investigated based on nanofiller type such as nanoclays, polysaccharides and carbonaceous nanofillers. Furthermore, the structures of starch and material preparation methods for their nanocomposites are also mentioned in this review. It is clearly presented that mechanical, thermal and barrier properties of plasticised starch can be improved with well-dispersed nanofillers in starch nanocomposites

Effect of the COVID-19 pandemic on surgery for indeterminate thyroid nodules (THYCOVID): a retrospective, international, multicentre, cross-sectional study

Background Since its outbreak in early 2020, the COVID-19 pandemic has diverted resources from non-urgent and elective procedures, leading to diagnosis and treatment delays, with an increased number of neoplasms at advanced stages worldwide. The aims of this study were to quantify the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic; and to evaluate whether delays in surgery led to an increased occurrence of aggressive tumours.Methods In this retrospective, international, cross-sectional study, centres were invited to participate in June 22, 2022; each centre joining the study was asked to provide data from medical records on all surgical thyroidectomies consecutively performed from Jan 1, 2019, to Dec 31, 2021. Patients with indeterminate thyroid nodules were divided into three groups according to when they underwent surgery: from Jan 1, 2019, to Feb 29, 2020 (global prepandemic phase), from March 1, 2020, to May 31, 2021 (pandemic escalation phase), and from June 1 to Dec 31, 2021 (pandemic decrease phase). The main outcomes were, for each phase, the number of surgeries for indeterminate thyroid nodules, and in patients with a postoperative diagnosis of thyroid cancers, the occurrence of tumours larger than 10 mm, extrathyroidal extension, lymph node metastases, vascular invasion, distant metastases, and tumours at high risk of structural disease recurrence. Univariate analysis was used to compare the probability of aggressive thyroid features between the first and third study phases. The study was registered on ClinicalTrials.gov, NCT05178186.Findings Data from 157 centres (n=49 countries) on 87 467 patients who underwent surgery for benign and malignant thyroid disease were collected, of whom 22 974 patients (18 052 [78 center dot 6%] female patients and 4922 [21 center dot 4%] male patients) received surgery for indeterminate thyroid nodules. We observed a significant reduction in surgery for indeterminate thyroid nodules during the pandemic escalation phase (median monthly surgeries per centre, 1 center dot 4 [IQR 0 center dot 6-3 center dot 4]) compared with the prepandemic phase (2 center dot 0 [0 center dot 9-3 center dot 7]; p&lt;0 center dot 0001) and pandemic decrease phase (2 center dot 3 [1 center dot 0-5 center dot 0]; p&lt;0 center dot 0001). Compared with the prepandemic phase, in the pandemic decrease phase we observed an increased occurrence of thyroid tumours larger than 10 mm (2554 [69 center dot 0%] of 3704 vs 1515 [71 center dot 5%] of 2119; OR 1 center dot 1 [95% CI 1 center dot 0-1 center dot 3]; p=0 center dot 042), lymph node metastases (343 [9 center dot 3%] vs 264 [12 center dot 5%]; OR 1 center dot 4 [1 center dot 2-1 center dot 7]; p=0 center dot 0001), and tumours at high risk of structural disease recurrence (203 [5 center dot 7%] of 3584 vs 155 [7 center dot 7%] of 2006; OR 1 center dot 4 [1 center dot 1-1 center dot 7]; p=0 center dot 0039).Interpretation Our study suggests that the reduction in surgical activity for indeterminate thyroid nodules during the COVID-19 pandemic period could have led to an increased occurrence of aggressive thyroid tumours. However, other compelling hypotheses, including increased selection of patients with aggressive malignancies during this period, should be considered. We suggest that surgery for indeterminate thyroid nodules should no longer be postponed even in future instances of pandemic escalation.Funding None.Copyright (c) 2023 Published by Elsevier Ltd. All rights reserved

Verursacht das Medizinstudium Depressionen oder sind Medizinstudierende bereits zu Studienbeginn depressiv? Eine Längsschnittstudie zu Depression und beeinflussenden Faktoren im ersten Semester des Medizinstudiums

Objective: In the past, medical students have been found to be at increased risk for depressive symptoms compared to the general population. This study addresses the question, whether medical students already show these elevated depression scores at the beginning of medical school or whether it is the studies of medicine that leads to symptoms of depression. Methods: In the winter semester 2018/2019, 148 medical students at a middle-sized German university answered a questionnaire during the first (T0) and last week (T1) of their first semester that examined various risk and resilience factors for initial depressive symptoms and their course. The severity of symptoms was assessed with the Beck´s Depression Inventory II (BDI-II). A subscale of the NEO-FFI was used to investigate the personality factor neuroticism.Results: Over the study period, the percentage of students suffering from at least mild depressive symptoms increased from 16.3% in the first week of their studies (T0) to 21.4% at the end of the first semester (T1). The use of drugs or medication, loneliness, mental overload, performance pressure and financial burden show the strongest influence on the development of depressive symptoms. Concerning surveyed resilience factors, in particular emotional support, physical workout and sufficient time for social contact appear to be protective. The more risk factors are concentrated on an individual, the higher its increase of depressive symptoms. The opposite is prevailing for the investigated resilience factors. Except for the use of drugs or medication, no other criterion than the BDI-II value at T0 was able to predict the BDI-II score at T1. This underlines that especially the interplay of factors is decisive.Conclusion: The findings of this study could indicate a worsening tendency of the BDI-II score in the further course of medical school. Ultimately, we emphasize the importance of offering preventive measures to medical students as early as possible.Zielsetzung: In vorangehenden Studien zeigte sich, dass Medizinstudierende im Vergleich zur allgemeinen Bevölkerung ein erhöhtes Risiko für depressive Symptome aufweisen. Diese Studie behandelt die Frage, ob Medizinstudierende bereits zu Beginn des Studiums erhöhte Depressionsraten aufweisen oder ob diese erst im Laufe des Studiums entstehen. Methoden: Im Wintersemester 2018/19 beantworteten 148 Medizinstudierende einer mittelgroßen, deutschen Universität einen Fragebogen während der ersten (T0) und letzten (T1) Woche ihres ersten Studiensemesters. Der Fragebogen untersuchte verschiedene Risiko- und Resilienzfaktoren für eine depressive Symptomatik und deren Verlauf. Der Schweregrad der Symptome wurde mit dem Becks-Depressions-Inventar II (BDI-II) erfasst. Eine Subskala des NEO-FFI wurde verwendet, um den Persönlichkeitsfaktor Neurotizismus zu erfassen. Ergebnisse: Während des Studienzeitraums nahm der Anteil an Studierenden, die unter mindestens milden depressiven Symptomen litten, von 16.3% in der ersten Woche des Studiums (T0) auf 21.4% in der letzten Woche des ersten Semesters (T1) zu. Der Gebrauch von Drogen oder Medikamenten, Einsamkeit, mentale Überforderung, Leistungsdruck und finanzielle Belastung zeigten den stärksten Einfluss auf die Entwicklung der depressiven Symptome. Was die untersuchten Resilienzfaktoren betrifft, so scheinen insbesondere emotionale Unterstützung, körperliches Training und ausreichend Zeit für soziale Kontakte protektiv zu wirken. Je mehr Risikofaktoren auf ein Individuum zutreffen, desto stärker nimmt die depressive Symptomatik zu. Bei den Resilienzfaktoren ist das Gegenteil der Fall. Abgesehen von der Einnahme von Drogen oder Medikamenten, sowie dem BDI-II-Wert zu T0, erwies sich kein weiterer Faktor als geeignet, den BDI-II-Wert zu T1 vorherzusagen. Dies weist darauf hin, dass der Interaktion der einzelnen Faktoren eine wichtige Rolle zukommt.Fazit: Die Ergebnisse dieser Studie weisen auf eine Verschlechterung des BDI-II-Wertes im weiteren Verlauf des Medizinstudiums hin. Letztlich möchten wir betonen, wie wichtig es ist, Medizinstudierenden so früh, wie möglich präventive Maßnahmen anzubieten