Role of multi-detector computed tomography in the evaluation of pancreatic tumors

AbstractObjectiveThe purpose of this study was to determine the role of multidetector computed tomography (MDCT) in evaluation and prediction of pancreatic tumors resectability.Patients and methodsThe study included 20 patients who had pancreatic masses, 16 males and 4 females, and their age range was 30–70years with a mean age of 58.0years. All the patients underwent non-contrast and contrast enhanced Multi-slice CT using a 16-slice machine. The gold standard for diagnosis was histopathology and operative data.ResultsAdenocarcinoma as reported by pathological studies was found in 8 patients, cyst adenocarcinoma in one patient, infiltrative adenocarcinoma in 2 patients, intraductal papillary mucinous tumor in 2 patients, mucinous cyst adenocarcinoma in one patient, pancreatic pseudo cyst in 2 patients and mucinous cystadenoma in 4 patients. According to MDCT criteria 6 patients were considered suitable for tumor resection and 14 patients were considered inoperable with unresectable tumor, one out of the 6 operable patients was unresectable during operation due to the invasion of the superior mesenteric vein with infiltration of the mesenteric root.ConclusionContrast-enhanced multiphase pancreatic imaging by multislice computerized tomography (MSCT) with its postprocessing techniques represents the image of choice for diagnosis and predicting pancreatic masses and resectability

Early outcome of pediatric pyeloplasty in kidneys with split renal function less than 10%: A prospective study of 25 cases

Objectives: To detect the outcome of pyeloplasty in kidneys with split renal function (SRF) less than 10% in the pediatric age group.Subjects and methods: We prospectively analyzed the data from 25 cases of ureteropelvic junction obstruction (UPJO) candidate for pyeloplasty with SRF less than 10%. Abdominopelvic ultrasonography and diuretic renogram using technetium-99 m diethylenetriamine Penta acetic acid (DTPA) were done in all cases. We studied the improvement in pelvic anteroposterior diameter (APD) postoperatively. We compared pre and postoperative SRF after six months and one year.Results: The median age was 24 months (3 months–11 years), male to female 2:1. The median preoperative SRF was 5% (range: 0%–10%) and the median APD of the renal pelvis was 3 cm (range: 2.2–5). There was significant improvement of median APD 0.8 cm (range: 0.5–1.9) (P value <0.05). There was a significant postoperative improvement in the median SRF (P-value <0.05) as the median SRF after 6 months and 1 year were 21% and 20%, respectively but there was no significant difference between SRF at six months and one year (P value 0.174).Conclusion: Pyeloplasty provides high rates of functional success even in very poorly functioning kidneys with SRF ≤10% by DTPA renogram in pediatric age group

Understanding hydraulic fracture mechanisms: From the laboratory to numerical modelling

The development of fracture networks associated with hydraulic fracturing operations are extremely complex multiphysics processes and there is still no accepted methodology for mapping or realistic recreating such fracture networks. This is an issue especially for modeling purposes, as, ideally, an accurate numerical representation, and subsequent numerical model, should be able to honor the trajectory, type, connectivity, and geometric properties of the complex fracture network generated. This research proposes a novel framework capable of conducting fluid flow numerical simulations based on mapped fracture networks induced during hydraulic fracturing laboratory experiments where a shale sample, under true triaxial reservoir stress conditions, is subjected to fluid injection to mimic a single stage open-hole in-situ hydraulic fracture operation. The resulting post-test fracture network of the shale sample is filled with fluorescent dyed epoxy and subsequently imaged. The images are segmented, and individual fractures are classified based on their geometrical characteristics, as parted bedding planes, opened natural fractures, and newly generated hydraulic fractures. The digital fracture network is numerically represented for fluid flow simulation using a dual-porosity model within the finite volume method. In the numerical reconstruction, fractures are implicitly represented in a set of cells with virtual fracture aperture. The properties of each grid cell are assigned based on fracture classification, and flow between grid cells is explicitly assigned based on the connectivity of the grid cells. Findings show faster fluid drainage parallel to bedding planes (horizontal) than in the vertical direction, indicating strong fluid flow anisotropy.Cited as: Abdelaziz, A., Ha, J., Li, M., Magsipoc, E., Sun, L., Grasselli, G. Understanding hydraulic fracture mechanisms: From the laboratory to numerical modelling. Advances in Geo-Energy Research, 2023, 7(1): 66-68. https://doi.org/10.46690/ager.2023.01.0

Information-Theoretic Bounds for Steganography in Multimedia

Steganography in multimedia aims to embed secret data into an innocent looking multimedia cover object. This embedding introduces some distortion to the cover object and produces a corresponding stego object. The embedding distortion is measured by a cost function that determines the detection probability of the existence of the embedded secret data. A cost function related to the maximum embedding rate is typically employed to evaluate a steganographic system. In addition, the distribution of multimedia sources follows the Gibbs distribution which is a complex statistical model that restricts analysis. Thus, previous multimedia steganographic approaches either assume a relaxed distribution or presume a proposition on the maximum embedding rate and then try to prove it is correct. Conversely, this paper introduces an analytic approach to determining the maximum embedding rate in multimedia cover objects through a constrained optimization problem concerning the relationship between the maximum embedding rate and the probability of detection by any steganographic detector. The KL-divergence between the distributions for the cover and stego objects is used as the cost function as it upper bounds the performance of the optimal steganographic detector. An equivalence between the Gibbs and correlated-multivariate-quantized-Gaussian distributions is established to solve this optimization problem. The solution provides an analytic form for the maximum embedding rate in terms of the WrightOmega function. Moreover, it is proven that the maximum embedding rate is in agreement with the commonly used Square Root Law (SRL) for steganography, but the solution presented here is more accurate. Finally, the theoretical results obtained are verified experimentally.Comment: arXiv admin note: substantial text overlap with arXiv:2111.0496

Synthesis of Ni-Fe-CO3_3 layered double hydroxide as Effective Adsorbent to remove Cr(VI) and ARS-dye from aqueous media

Ni$^2$/Fe$^{3＋}$LDH, (Ni-Fe-CO3 LDH) with Ni/Fe molar ratio 3.0 was synthesized by co-precipitation for the remediation of chromium (VI), and Alizarine Red-S (ARS-dye) as anionic species. The investigated adsorbent was characterized by TGA, SEM, XRD, BET and FTIR. The effect of the hydrogen ion concentration of the medium, shaking time, ARS-dye and/or Cr(VI) concentration and adsorbents mass on the process was studied. The results of Ni-Fe-CO$_3$ LDH fitted well with the pseudo-second-order model. Langmuir isotherm is more favor than the Freundlich isotherm with maximum capacity ($Q_{max}$) of 69.9 and 6.1 mg/g for ARS-dye and Cr(VI), respectively

Single puncture combined lumbar erector spinae plane and quadratus lumborum block (SEQ block) in acetabular fracture surgeries: randomized clinical trial

Background Acetabular fracture surgery can cause severe postoperative pain. A combined lumbar erector spinae plane block and paraspinous sagittal shift quadratus lumborum block may augment analgesia. Methods Fifty two patients undergoing posterior column acetabular surgery were divided into: Group Single puncture combined lumbar Erector spinae and Quadratus lumborum block (SEQ): patients who received SEQ block before anesthesia; and Group morphine (MOR), those who received general anesthesia (GA) and morphine. Results Demographic characteristics were comparable. The heart rate and mean arterial blood pressure were significantly lower in the SEQ group than in the MOR group between 60 and 180 min intraoperatively (P < 0.001). Postoperative resting and dynamic visual analogue scale scores in the SEQ group were significantly lower than those in the MOR group at all studied periods (P = 0.022–0.001), except at 20 and 24 h postoperatively. Fentanyl was required in all MOR group patients at a mean dose of 110.0 ± 28.42 µg while 18 patients required fentanyl in SEQ group at a mean dose of 60.55 ± 25.54 µg. Postoperative morphine consumption was significantly less in SEQ group (6.33 ± 2.37 mg) than MOR group (17.0 ± 2.55 mg). Postoperative nausea and vomiting were recorded in eight and four patients in MOR and SEQ group, respectively. No complications associated with the block technique were observed. Conclusions The SEQ block reduces the postoperative opioid consumption and provides stable intra and postoperative hemodynamics without observed complications in posterior column acetabular surgery

Graphene Oxide@Heavy Metal Ions (GO@M) Complex Simulated Waste as an Efficient Adsorbent for Removal of Cationic Methylene Blue Dye from Contaminated Water

Graphene oxide (GO) was heavily used in the adsorption process of various heavy metal ions (such as copper (Cu) and iron (Fe) ions), resulting in a huge waste quantity of graphene oxide@metal ions complex. In this research, the authors try to solve this issue. Herein, the GO surface was loaded with divalent (Cu2+) and trivalent (Fe3+) heavy metal ions as a simulated waste of the heavy metal in various removal processes to form GO@Cu and (GO@Fe) composites, respectively. After that, the previous nanocomposites were used to remove cationic methylene blue (MB) dye. The prepared composites were characterized with a scanning electron microscope (SEM), transition electron microscope (TEM), Fourier transmission infrared (FTIR), Raman, and energy-dispersive X-ray (EDS) before and after the adsorption process. Various adsorption factors of the two composites towards MB-dye were investigated. Based on the adsorption isotherm information, the adsorption process of MB-dye is highly fitted with the Langmuir model with maximum capacities (mg g−1) (384.62, GO@Cu) and (217.39, GO@Fe). According to the thermodynamic analysis, the adsorption reaction of MB-species over the GO@Cu is exothermic and, in the case of GO@Fe, is endothermic. Moreover, the two composites presented excellent selectivity of adsorption of the MB-dye from the MB/MO mixtur

Unaligned inductance calculation using flux tube approach for rotor conducting screen-based SRM

This paper investigates the effect of utilizing rotor conducting screens within a switched reluctance machine. Conducting, non-magnetic materials such as aluminium or copper are inserted into the interpole regions of the rotor. The effective unaligned inductance decreases, which increases the conversion area allowing the machine to develop more power. Predicting machine performance implies knowing the value of the unaligned inductance. A procedure for calculating the effective unaligned inductance for screened motors using the flux tube method is presented. Finite element analysis results establish the validity of the proposed calculation method. A detailed design procedure for screened SRM is presented

Recent Progress and Potential Biomedical Applications of Electrospun Nanofibers in Regeneration of Tissues and Organs

Electrospun techniques are promising and flexible technologies to fabricate ultrafine fiber/nanofiber materials from diverse materials with unique characteristics under optimum conditions. These fabricated fibers/nanofibers via electrospinning can be easily assembled into several shapes of three-dimensional (3D) structures and can be combined with other nanomaterials. Therefore, electrospun nanofibers, with their structural and functional advantages, have gained considerable attention from scientific communities as suitable candidates in biomedical fields, such as the regeneration of tissues and organs, where they can mimic the network structure of collagen fiber in its natural extracellular matrix(es). Due to these special features, electrospinning has been revolutionized as a successful technique to fabricate such nanomaterials from polymer media. Therefore, this review reports on recent progress in electrospun nanofibers and their applications in various biomedical fields, such as bone cell proliferation, nerve regeneration, and vascular tissue, and skin tissue, engineering. The functionalization of the fabricated electrospun nanofibers with different materials furnishes them with promising properties to enhance their employment in various fields of biomedical applications. Finally, we highlight the challenges and outlooks to improve and enhance the application of electrospun nanofibers in these applications

Review of the Recent Advances in Electrospun Nanofibers Applications in Water Purification

Recently, nanofibers have come to be considered one of the sustainable routes with enormous applicability in different fields, such as wastewater treatment. Electrospun nanofibers can be fabricated from various materials, such as synthetic and natural polymers, and contribute to the synthesis of novel nanomaterials and nanocomposites. Therefore, they have promising properties, such as an interconnected porous structure, light weight, high porosity, and large surface area, and are easily modified with other polymeric materials or nanomaterials to enhance their suitability for specific applications. As such, this review surveys recent progress made in the use of electrospun nanofibers to purify polluted water, wherein the distinctive characteristics of this type of nanofiber are essential when using them to remove organic and inorganic pollutants from wastewater, as well as for oil/water (O/W) separation