Acute intestinal obstruction revealing synchronous gastrointestinal stromal tumors in a small bowel diverticulum and mucinous adenocarcinoma of the colon: a case report

Gastrointestinalstromal tumors are rare neoplasms and represent 0,1% to 3% of all gastrointestinal cancers. They are the most frequent mesenchymal neoplasms of the gastrointestinal tract with a malignant potential and unpredictable behavior. The synchronous association with other primary gastrointestinal carcinoma has been rarely reported in the literature with increasing number in the last ten years. The associated Gastrointestinalstromal tumor is usually discovered incidentally during surgery for carcinoma. The limited number of these cases cannot confirm the existence of a common factor in tumorigenesis of these different tumors and other studies are needed to clarify the possible association. We report the first case in the literature of synchronous primary Gastrointestinalstromal tumors developed in small bowel diverticulum and mucinousadenocarcinoma of the colon. Key words: Synchronous, Gastrointestinalstromal tumors, Adenocarcinoma, Colon

Effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults: a retrospective cephalometric assessment

Background. This study aimed to assess the effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults by cephalometric assessment. Methods. This retrospective study was conducted on 142 cephalograms of patients who underwent orthodontic treatment with premolar extraction in four groups of (I) 40 class I patients with bimaxillary protrusion and maximum anchorage, (II) 40 class I patients with moderate crowding and anchorage, (III) 40 class II patients with maximum anchorage, and (IV) 22 skeletal class III patients with maximum anchorage. The dimensions of the nasopharynx, velopharynx, oropharynx, and hypopharynx, and hyoid bone position were assessed on pre- and postoperative lateral cephalograms using AudaxCeph v6.1.4.3951 software. Data were analyzed by the Chi-square test, paired t-test, and Pearson's correlation test (alpha D 0.05). Results. A significant reduction in oropharyngeal, velopharyngeal, and hypopharyngeal airway dimensions was noted in groups I, III, and IV (P <0:001), which was correlated with the magnitude of retraction of upper and lower incisors (r =0:6-0:8). In group II, a significant increase was observed in oropharyngeal and velopharyngeal dimensions (P < 0:001). A significant increase in nasopharyngeal dimensions occurred in all groups (P < 0:001). Also, in groups I and III, the position of hyoid bone changed downwards and backwards, which was correlated with reduction in airway dimensions (r =0:4-0:6). Conclusion. According to the present results, extraction orthodontic treatment affects upper airway dimensions and hyoid bone position. Maximum anchorage decreases airway dimensions while moderate anchorage increases airway dimensions

Time-averaged heat transfer and vortex shedding of a singular and twin heated bluff bodies in cross flow

Flow characteristics in the onset of vortex shedding and heat transfer pattern over a single and two same-sized square prisms placed in tandem are studied numerically. All simulations are carried out for Reynolds numbers range varying from 1 to 200 and spacing between the prisms in the order of five widths of prism for in tandem configuration. The calculations are done employing a finite volume in-house computer program according to semi-implicit method for pressure linked equations-consistent (SIMPLEC) numerical procedure and nonstaggered mesh in 2-dimensional, steady/unsteady and incompressible flow regimes. The instantaneous and time-averaged streamlines as well as iso-therm pattern for different Reynolds numbers are analysed. Furthermore, the influence of Reynolds number and the onset of vortex shedding on the flow pattern are studied in detail. Three distinct patterns namely fully-attached, trailing-edge separation and leading-edge separation were observed

Salivary nitric oxide levels in adults with different DMFT scores in a selected iranian population: a cross-sectional study

Objectives: Due to the emphasis on the protective and antimicrobial role of Nitric Oxide against gas-trointestinal diseases, investigating its relationship with dental caries is a right topic. Therefore, this research has investigated the amount of saliva Nitric Oxide in different volumes of DMFT indicator in adults. Material and Methods: In this descriptive-analytical cross-sectional study, 80 participants (20-35 years old), without a history of systemic disease and drug use participated as research sam-ples, (53.8% of the participants in the study were women). Participants were selected from patients who had visited dental Department. The participants were divided in four groups based on DMFT (DMFT=0, 1≤DMFT≤3, 3<10, DMFT≥10). Non-stimulating saliva was collected from all participants between 9-11 am in a calibrated tube. Saliva Nitric Oxide was measured using a Nitrous Oxide test, based on the Griess reaction. We used a correlation test to analyze quantitative variables, and t-test or ANOVA for qualitative and quantitative variables. Results: A significant relationship between DMFT and age was identified. At different levels of DMFT, significant relationship between DMFT and sex was not found. In different groups of DMFT, no significant relationship between Nitric Oxide and DMFT exist. Conclusion: The level of Nitric Oxide saliva was not affected by the amount of DMFT

Flow behavior and mechanical properties of multi-pass thermomechanically processed 7075 Al-alloy

Research on multi-pass hot processing of 7075 Al-alloy was rarely discussed. This study aims to design and evaluate different thermomechanical processing strategies (TMPS) to produce 3 mm-thick sheets of 7075 Al-alloy. A physical simulation was performed using the hot compression test of a Gleeble 3500 to study flow mechanisms and microstructural evolution, while an experimental investigation was carried out using a rolling mill to examine the effect of TMPS on the mechanical properties. Four hot forming strategies were designed and tested at a constant strain rate of 0.1 s−1 over a temperature range of 200–450 °C. These strategies involved applying a constant amount of deformation of 65–70% in single (SP), double (DP), triple (TP), and quadruple (QP) passes of thermomechanical processing to study the influence of multi-pass thermomechanical processing on the final mechanical properties and industrial feasibility. The microstructure analysis showed a significant refinement and more uniform distribution of precipitates with an increasing number of passes, as observed through optical micrographs and the full width at half maximum (FWHM)-position relationship of XRD data. The results indicate that QP is the optimum strategy for producing the best mechanical properties in the shortest production time

The Pediatric Allergy and Immunology Unit of Ain Shams University in times of SARS-CoV-2 pandemic: approach and challenges

The Pediatric Allergy and Immunology (PAI) Unit of Ain Shams University, founded in 1988 by Professor Yehia El-Gamal and currently headed by Professor Shereen Reda, is a tertiary referral center for pediatric allergy, primary immunodeficiency, and rheumatology patients in Egypt. It serves more than 1300 patients with different immunological disorders, with an outpatient and inpatient sections and investigational laboratory. With the widespread of the SARS-CoV-2 and its declaration as a "pandemic", and owing to the heterogeneity of the different disorders managed and followed up in the unit, several measures have been taken in order to provide the necessary services for the patients. This service should maintain a rational balance between the need to mitigate the virus spread and to provide the optimum care for those who get infected, when in the meantime keep their original disease morbidity and mortality to the minimum. These measures were taken by the members of the PAI unit with the help of the head management team of Children’s Hospital, Ain Shams University and were subjected to continuous modification based on the evolving situation, emerging information, problems faced and the availability of human and medical resources

Performance of multiphase scaffolds for bone repair based on two-photon polymerized poly(d,l-lactide-co-ɛ-caprolactone), recombinamers hydrogel and nano-HA

Multiphase hybrids were fabricated from poly(d,l-lactide-co-ɛ-caprolactone) (PLCL) copolymer scaffolds impregnated with silk-elastin-like recombinamers (SELRs) hydrogel containing 2 wt% hydroxyapatite nanoparticles (nHA). The PLCL scaffolds, triply-periodic minimal surface geometry, were manufactured using two-photon stereolithography. In vitro degradation studies were conducted on PLCL scaffolds in inflamed tissue mimic media (pH ~ 4.5–6.5) or phosphate buffered saline (PBS) at 37 °C. Compression test revealed instant shape recovery of PLCL scaffolds after compression to 70% strain, ideal for arthroscopic delivery. Degradation of these scaffolds was accelerated in acidic media, where mass loss and compressive properties at day 56 were about 2–6 times lower than the scaffolds degraded in PBS. No significant difference was seen in the compressive properties between PLCL scaffolds and the hybrids due to the order of magnitude difference between the hydrogels and the PLCL scaffolds. Moreover, degradation properties of the hybrids did not significantly change by inclusion of SELR+/−nHA nanocomposite hydrogels. The hybrids lost approximately 40% and 84% of their initial weight and mechanical properties, respectively after 112 days of degradation. Cytotoxicity assessment revealed no cytotoxic effects of PLCL or PLCL-SELR+/−2%nHA scaffolds on bone marrow-derived human Mesenchymal Stem Cells. These findings highlight the potential of these hybrid constructs for bone and cartilage repair

Computational mechanical characterization of geometrically transformed Schwarz P lattice tissue scaffolds fabricated via two photon polymerization (2PP)

Schwarz P unit cell-based tissue scaffolds comprised of poly(D,L-lactide-co-caprolactone)(PLCL) fabricated via the additive manufacturing technique, two-photon polymerisation (2PP) were found to undergo geometrical transformations from the original input design. A Schwarz P unit cell surface geometry CAD model was reconstructed to take into account the geometrical transformations through CAD modeling techniques using measurements obtained from an image-based averaging technique before its implementation for micromechanical analysis. Effective modulus results obtained from computational mechanical characterization via micromechanical analysis of the reconstructed unit cell assigned with the same material model making up the fabricated scaffolds demonstrated excellent agreement with a small margin of error at 6.94% from the experimental mean modulus (0.69 0.29MPa). The possible sources for the occurrence of geometrical transformations are discussed in this paper. The interrelationships between different dimensional parameters making up the Schwarz P architecture and resulting effective modulus are also assessed and discussed. With the ability to accommodate the geometrical transformations, maintain efficiency in terms of time and computational resources, micromechanical analysis has the potential to be implemented in tissue scaffolds with a periodic microstructure as well as other structures outside the field of tissue engineering in general

Unveiling the Local Atomic Arrangements in the Shear Band Regions of Metallic Glass

The prospective applications of metallic glasses are limited by their lack of ductility, attributed to shear banding inducing catastrophic failure. A concise depiction of the local atomic arrangement (local atomic packing and chemical short‐range order), induced by shear banding, is quintessential to understand the deformation mechanism, however still not clear. An explicit view of the complex interplay of local atomic structure and chemical environment is presented by mapping the atomic arrangements in shear bands (SBs) and in their vicinity in a deformed Vitreloy 105 metallic glass, using the scanning electron diffraction pair distribution function and atom probe tomography. The results experimentally prove that plastic deformation causes a reduction of geometrically favored polyhedral motifs. Localized motifs variations and antisymmetric (bond and chemical) segregation extend for several hundred nanometers from the SB, forming the shear band affected zones. Moreover, the variations within the SB are found both perpendicular and parallel to the SB plane, also observable in the oxidation activity. The knowledge of the structural–chemical changes provides a deeper understanding of the plastic deformation of metallic glasses especially for their functional applications and future improvements