Clinical-radiological features and diagnostic modalities for mediastinal melioidosis

Melioidosis is a potentially life-threatening infection caused by the Gram-negative bacillus Burkholderia pseudomallei. Mediastinal melioidosis has a range of clinical presentations, making it difficult to diagnose: we therefore reviewed the evidence on the clinical characteristics, radiological features and invasive diagnostic modalities or interventions. An electronic search was conducted on three databases (PubMed, SCOPUS, Google Scholar) from November to December 2022. The initial search yielded 120 results, of which 34 studies met the inclusion criteria, but only 31 full-texts were retrievable. Among these, 4 were cohort studies, 26 case reports or series and 1 a conference abstract. The four main themes covered were mediastinal melioidosis as a diagnostic dilemma, unexpected complications, invasive interventions or an accompanying thoracic feature. Radiological manifestations included matting, necrosis and abscess-like collection. Severe presentations of mediastinal melioidosis included superior vena cava obstruction, sinus tract formation and pericardial tamponade. Transbronchial needle aspiration was the most common invasive diagnostic modality. Further research is needed to understand the relationship between the thoracic features of melioidosis on patient prognosis, its relationship to melioidosis transmission and potential preventive measures.

Post-cholecystectomy bile reflux gastritis: Prevalence, risk factors, and clinical characteristics

OBJECTIVE

Bile reflux gastritis is caused by the backward flow of duodenal fluid into the stomach. A retrospective cohort study was performed to estimate the prevalence and risk factors of bile reflux gastritis postcholecystectomy, and to evaluate the endoscopic and histopathologic changes in gastric mucosa.

METHODS

Patients with refractory upper abdominal pain right below the ribs with symptoms of bloating, burping, nausea, vomiting, and bile regurgitation during the period from January 2018 to December 2020, submitted to Zagazig University Hospitals were enrolled in this study. The studied 64 patients were divided into two groups; the control group (CG): 30 subjects who had never undergone any biliary interventions, and the post-cholecystectomy group (PCG): 34 patients who had undergone cholecystectomy.

RESULTS

The prevalence of bile reflux gastritis was (16.7%) and (61.8%) in CG and PCG, respectively. Diabetes, obesity, elevated gastric bilirubin, and elevated stomach pH were all risk factors for bile reflux gastritis in both groups (r = .28,.48,.78,.57 respectively). Age, sex, epigastric pain, heartburn, vomiting, and the existence of bile reflux gastritis, on the other hand, had no correlation.

DISCUSSION

After a cholecystectomy, bile reflux gastritis is prevalent, especially among obese and diabetic patients.

Structural, optical and photocatalytic properties of mesoporous CuO nanoparticles with tunable size and different morphologies

Nanomaterials with controllable particle size and shape have fascinating properties. Herein, CuO nanoparticles (NPs) with controlled particle size and morphology are obtained via a simple co-precipitation approach. Variation of the reaction medium composition steers the variation of both particle size and morphology of the CuO NPs. The reaction was performed in ethanol–water solutions with different volume to volume ratios (v/v%) i.e. 0, 25, 50, and 100%. XRD of the obtained samples revealed a drop in their particle size from ∼13 to ∼7 nm when the aqueous medium is entirely replaced by the ethanolic medium. TEM and HR-TEM investigations have pointed to the formation of CuO NPs with rod-like shapes in water (diameter = 15 nm and length = 200 nm). Whereas, spherical NPs with a diameter of 7.2 nm are obtained in ethanol. Structural analysis of CuO samples obtained in different media was done applying the Rietveld method. The volume of the monoclinic unit cell of CuO is increased to 81.869 ų when water (81.207 ų) is completely substituted by ethanol. Moreover, the internal local strain (ε) and the dislocation density (δ) values increase from 2.78 × 10⁻³ to 4.64 × 10⁻³ and 0.592 × 10⁶ to 1.93 × 10⁶ line per m², respectively by changing from aqueous to ethanolic medium. The optical band gap (E_g) determined using Tauc's equation for the direct transition is increased from 2.2 to 2.65 eV when water is totally replaced by ethanol. The feasibility of both CuO samples as photocatalysts for the degradation of Congo red was tested. CuO prepared in pure water showed remarkably high efficiency during the first 25 min of illumination. Both samples showed complete dye removal after 35 min. Ultimately, this work presents a simple and green approach for the preparation of CuO NPs with tunable particle size, varied morphological shapes, high surface area, and different structural and optical properties merely through controlling the ethanol content in water.

Ethanol/water percentage plays a crucial role in tuning of the particle size and morphology, hence the structural, optical and photocatalytic properties of the synthesized CuO nanomaterials.

Temperature Dependence of Absorption Spectra and Optical Parameters for Polyester Films of Dibenzylidene Cyclohexanone

Effect of temperature on the optical absorption spectra and optical parameters is investigated in new synthesized polyester films of poly[oxyiso-phthaloyloxy(2-methoxy- p-phenylene)methylidyne(2-oxo-1, 3-cyclohexanediylidyne)methylidyne(3-methoxy- p-phenylene)] (I) and poly[oxysebacoyloxy-(2-methoxy- p-phenylene) methylidene (2-oxo-1, 3-cyclohexanedi-ylidene)-methy-lidene-(3-methoxy- p-phenylene)] (II). Absorption measurements are carried out in the temperature range 80–370 K and in the photon energy range 1.9–4 eV. The optical absorption spectra of polymers I and II reveal excitonic absorption bands at 80 and 120 K respectively. These bands are associated with n →π* optical transitions along polymer backbone chains. Analysis of optical absorption data indicates that the Tauc equation for indirect optical transitions successfully explains the optical absorption process in polymeric film I, whereas Urbach’s law is more suitable for describing the optical absorption in polymeric film II. Temperature dependence of the optical bandgap, Eoptg, the Tauc slope √B, and the width of Urbach’s tail states ( Ee) exhibits anomalous parabolic behaviour which can be explained in terms of various current theories. Moreover, DSC, x-ray diffraction and morphological studies by TEM are used in the explanation of the experimental results. The values of optical parameters, as well as the temperature coefficient of the optical bandgap for these polymers, are calculated and reported.

Comparative Morphology of Atalodera spp. and Thecavermiculatus spp. (Heteroderidae) with Scanning Electron Microscopy

SEM examination of second-stage juveniles (J2) and adults of Atalodera ucri, A. lonicerae (syn. Sherodera lonicerae), Thecavermiculatus sp. (undescribed new species), T. andinus, and T. crassicrustatus revealed new characters. A primitive en face pattern with six separate lips occurs in J2 of Thecavermiculatus spp. examined and in about half the polymorphic A. lonicerae. A derived en face pattern with fused adjacent submedial lips occurs in the other half of A. lonicerae and all A. ucri. Posteriorly, the J2 head of all species is annulated. The primitive en face pattern also occurs in males of A. lonicerae and Thecavermiculatus spp., and posteriorly the head of these species consists of plates. Fewer plates occur rarely in males of A. ucri. Males of A. ucri have a derived en face pattern where lips are fused and the head is annulated. Fusion of lips occurs rarely in males of A. lonicerae. Females of all species have similar derived en face patterns. En face patterns of J2 and males o f Atalodera and Thecavermiculatus may aid in species identification and to elucidate intergeneric relationships, but en face characters shared by the two genera are primitive and are not useful for demonstrating monophyly. Perineal region of females indicates the closeness of the vulval-anal distance, as a derived character, which is shared by Atalodera and most Thecavermiculatus spp. suggesting possible monophyly. T. andinus, while having a similar en face pattern to J2 of other Thecavermiculatus species, lacks the derived character of the perineal region. Phasmid openings were not observed in adults of any of the species examined.

Comparative Morphology of Meloidodera spp. and Verutus sp. (Heteroderidae) with Scanning Electron Microscopy

Scanning electron microscopy (SEM) of second-stage juveniles (J2), males, and females of Meloidodera floridensis, M. charis, M. belli, and Verutus volvingentis reveals detailed characteristics of the head region, lateral field, phasmid, body striae, vulva, and perineal region. In M. charis and M. belli the en face pattern conforms to a basic pattern in which the labial disc is surrounded by six lips (sectors) of the first head annulation. In J2 the head has additional annulations, whereas in males annulation is replaced by longitudinal blocks. Conversely, J2 and males of M. floridensis and V. volvingentis each have a unique derived face pattern with fusion of various lip components and with head annulation. All six lips of females of M. charis and M. belli are fused, whereas females of M. floridensis and V. volvingentis have distinct lateral lips. Lateral fields vary among species, with only slight differences at the anterior and posterior ends of the lateral lines and in the spatial relation of the lines to phasmid openings. Phasmid openings are present in adults of Meloidodera spp., but were not observed in adults of V. volvingentis; in this respect, the female perineal pattern of Verutus is different from Meloidodera spp, The very large vulva (+/- 48 mum long) of V. volvingentis is in sharp contrast to the minute vulva (+/- 6 mum long) in a population of M. charis from San Bernardino. Morphological characters revealed by SEM will be most informative when investigated throughout Heteroderidae and incorporated with additional characters for a phylogenetic analysis of the family.

Cryphodera utahensis n. sp., (Heteroderidae), A New Species from Wild Rose in Utah

A new species of Cryphodera Colbran, 1966, parasitic on wild rose (Rosa sp. L.), is described from Utah, USA. Cryphodera utahensis n. sp. most closely resembles C. podocarpi (Wouts, 1973) Luc et al., 1978, but is distinct with respect to a number of characters including juveniles with a longer esophagus (206 versus 142 mum), shorter tail (47 versus 69 mun), and four rather than three incisures in the lateral field. Females of C. utahensis have a terminal protuberance which is more pronounced than in other species. Scanning electron microscope observations of the lip region of males indicate a labial disc surrounded by six lip sectors. However, the remainder of the lip region is comprised of irregularly-shaped plates; similar patterns with longitudinal striae apparently characterize males throughout the genus. The lip pattern of juveniles of C. utahensis n. sp. includes an oval labial disc surrounded by six lip sectors; transverse striae extend the height of the lip region without longitudinal striae. The type locality of C. utahensis confirms a broader distribution of the genus than was indicated for other species, which are limited to Australia (Queensland) and New Zealand.

A new route to the synthesis of cyclitol derivatives

Three cyclitol derivatives, 2,4/3-triacetoxycyclohexanone diethyl dithioketal (XVIII), and 2,3,4-tri-O-acetyl-1-O-ethyl-2,4/1,3-cyclohexanetetrol (XXA) and 2,3,4-tri-O-acetyl-1-O-ethyl-1,2,4/3-cyclohexanetetrol (XXB), have been synthesized via the cyclisation of 2,3,4-tri-O-acetyl-5,6-dideoxy-D-xylo-hex-5-enose diethyl dithioacetal (XIV) and the cyclisation of 2,3,4-tri-O-acetyl-5,6-dideoxy-D-xylo-hex-5-enose diethyl acetal (XV) under ultraviolet or direct sunlight, in aqueous acetone.