Non-homogeneous Mass Research Articles

Physical pendulum—a simple experiment can give comprehensive information about a rigid body

A simple experiment with a physical pendulum examining some aspects of rigid body motion is presented in this paper. The experiment consists of measuring the period of oscillation of a rod with non-homogeneous mass distribution used as a physical pendulum, dependent upon the position of the pivot axis. The obtained dependence provides sufficient information to calculate the position of the centre of mass, moment of inertia of the rigid body and local gravitational acceleration. This experiment is intended for secondary school and undergraduate students.

Settling velocities of multifractal flocs formed in chemical coagulation process

A number of different flocculation mechanisms are involved in the formation of chemical coagulation flocs. Consequently, two flocs with the same size may have been formed by different mechanisms of aggregation and therefore have different arrangement of primary particles. As a result, two flocs with the same size may have different masses or mass distributions and therefore, different settling velocities. Although the correct estimation of the floc mass and density is critical for the development of the floc settling model, none of the suggested floc settling models incorporate the information on mass distribution and variable density of flocs. A probability-based method is used to determine the floc fractal dimensions on floc images. The results demonstrated that flocs formed in lime softening coagulation are multifractal. The multifractal spectra indicated the existence of a multiple fractal dimensions as opposed to the unique box-counting dimension which is a morphology-based fractal dimensions typically introduced into the Stokes' Law. These fractal dimensions may provide information on the flocs' aggregation mechanism, floc's structure, and the distribution of mass inside the floc. More research is required to investigate how to utilize the information obtained from the multifractal spectra to incorporate the variable floc density and nonhomogeneous mass distribution of flocs into the floc settling models.

A Very Rare Complication After Appendectomy in a Young Adult Patient: Abscess of the Greater Omentum

An 18-year-old male patient was operated on for perforated appendicitis. An appendectomy combined with an omental resection was performed. On the 6th postoperative day, chickenpox was diagnosed, and the patient was transferred to an infectious diseases hospital. On the 16 th postoperative day, the patient was readmitted with pain in the area of the postoperative scar, and body temperature of 38 o C . Substantial tenderness in the right iliac fossa without rigidity and peritoneal irritation was found on examination. By ultrasonography, a non-homogeneous hypoechoic mass measuring 40 × 37 mm without clear borders in the right iliac fossa was visualized, with a small amount of free fluid. The patient was reoperated on. An abscess of the greater omentum was found, and resection of an omental mass with the abscess cavity was performed. The postoperative course was uneventful, and the patient was discharged on the 15 th day. We discuss previously published data on postoperative omentitis and omental abscess. Our case is a very rare case of an omental abscess that developed after appendectomy in a young adult patient. J Med Cases. 2014;5(1):36-39 doi: http://dx.doi.org/10.4021/jmc1654e

Push‐out strength of root fillings with or without thermomechanical compaction

To evaluate the influence of thermomechanical compaction (Tagger's hybrid technique - THT) on the push-out strength of several root filling materials to root dentine. Root canals of eighty roots in human canines were prepared with the ProTaper system and filled with one of the following materials, using either lateral compaction (LC) (n = 40) or THT (n = 40): AH Plus/gutta-percha (GP) (n = 10), Sealer 26/GP (n = 10), Epiphany SE/Resilon (n = 10) and Epiphany SE/GP (n = 10). Three 2-mm-thick dentine slices were obtained from each third of each root. The root filling in the first slice was subjected to a push-out test to evaluate the bond strength of the materials to intraradicular dentine. Data (in MPa) were analysed using anova and post hoc Tukey's test (P < 0.05). Failure mode was determined at × 25 magnification. The other two slices were prepared for scanning electron microscopy (SEM) to examine the surface of the filling materials. Lateral compaction (1.34 ± 1.14 MPa) was associated with a significantly higher bond strength (P < 0.05) than the THT (0.97 ± 0.88 MPa). AH Plus/GP (2.23 ± 0.83 MPa) and Sealer 26/GP (1.86 ± 0.50 MPa) had significantly higher bond strengths than the other materials and differed significantly from each other (P < 0.05). There was a significant difference (P < 0.05) between the coronal (1.36 ± 1.15 MPa), middle (1.14 ± 1.05 MPa) and apical thirds (0.95 ± 0.83 MPa). Considering the technique and root filling material interaction, AH Plus/GP-LC was associated with the highest mean values (2.65 ± 0.66 MPa) (P < 0.05). Sealer 26/GP-LC (2.10 ± 0.46 MPa), AH Plus/GP-THT (1.81 ± 0.78 MPa) and Sealer 26/GP-TH (1.63 ± 0.44 MPa) had intermediate values that were not significantly different from each other (P > 0.05). Epiphany SE was associated with the lowest mean values (3.70 ± 0.86 MPa) (P < 0.05), regardless of the root filling technique and type of solid material (cone). Adhesive failures predominated in the specimens filled with Epiphany SE, whilst mixed and cohesive failures were more frequent in those filled with AH Plus and Sealer 26, regardless of the root filling technique. SEM analysis revealed that LC produced a dense and well-compacted filling whilst the use of a hybrid thermomechanical technique resulted in the solid material (GP or Resilon) intermingled within sealer to form a nonhomogenous mass. Lateral compaction was associated with higher bond strengths of the materials to intraradicular dentine than a hybrid technique using thermomechanical compaction. The greatest push-out strengths were obtained when the canals were filled with LC of AH Plus and GP cones.

Portal Hypertension Due to Alveolar Echinococcosis and Recanalized Paraumbilical Vein

Hepatic alveolar echinococcosis is an uncommon parasitic disease caused by Echinococcus multilocularis. It carries high fatality rates and poor prognosis if not diagnosed early and managed correctly. We report a 29-year-old female patient who admitted to our clinic with fatigue, weight loss and abdominal bloating in her right upper quadrant. Physical examination revealed the presence of a large palpable mass in her right upper quadrant, ascites and bilateral pedal edema. Computed tomography revealed a large non-homogeneous mass located in the right lobe of the liver and a dilated paraumbilical vein arising from the left branch of the portal vein. Echinococcus serology assessed by enzyme-linked immunosorbent assay was noted to be positive. Histopathologic examination of the hepatic mass was consistent with alveolar echinococcosis. The patient’s complaints were determined as being related to cirrhosis due to alveolar echinococcosis. Alveolar echinococcosis must be considered in patients with portal hypertension of uncertain etiology, especially in endemic regions.

Laparoscopic treatment of a phytobezoar in the duodenal diverticulum – Report of a case

INTRODUCTIONPrimer small intestine bezoar is seen rarely. It frequently arises from underlying small intestine pathologies (diverticle, tumor, stricture etc.). We report a very rare case of disopyrobezoar in the duodenal diverticulum, a kind of phytobezoar caused by persimmons, which was treated laparoscopically. PRESENTATION OF CASEThe 47-year-old patient applied to polyclinic with complaints of epigastric tenderness, occasional distension, and acid regurgitation. In endoscopical examination, impacted bezoar was determined in the diverticulum in the duodenum. Because it is too hard, it was unable to remove endoscopically. On the abdominal tomography, a smooth-bounded non-homogeneous mass including gas and soft tissue areas in the 2nd portion of the duodenum was detected. A barium meal confirmed the presence of a 5cm diameter diverticulum on the lateral wall of the second portion of the duodenum. It also showed an intraluminalfilling defect as well as the mottled appearance of the bezoar. Learned from history of the patient, that the patient consumed over persimmon in childhood. DISCUSSIONGenerally, duodenal diverticles are asymptomatic. Surgical treatment is rarely necessary because of complications such as bleeding, perforation, abdominal pain, bezoar formation. As well as using methods such as gastric lavage, enzymatic dissolution, endoscopical fragmentation in the treatment of phytobezoar, their chances of success are low because its structure is rigid. Usually, surgical intervention is required. CONCLUSIONFor the treatments of bezoar cases located in the small intestine, laparoscopic surgical method is a safe and feasible method in selected cases.

Breast Hamartoma: Mammographic Findings

Breast Hamartoma: Mammographic Findings

Metastatic Ureteral Involvement of Non-Small Cell Lung Cancer

Metastases from a variety of malignant tumors can involve the ureters, but ureteral involvement by lung cancer is extremely rare and usually described at autopsy. We report a rare case of a 76-year-old man who presented with a three-month history of right flank dullness and was noted to have a nonhomogeneous retroperitoneal mass with hydronephrosis of the right kidney on computed tomography of the abdomen. Computed tomography of the thorax showed a nodule in the lower lobe, measuring 3 × 2 cm, in the right lung. After excluding the presence of other primary tumors and metastases, we reached a final diagnosis of solitary retroperitoneal metastasis of adenocarcinoma of the lung. Although rare, in patients of non-small cell lung cancer, presence of hydronephrosis should alert the physician to the possibility of metastasis.

Synchronous Meckel's diverticulum and gastrointestinal stromal tumour presenting as acute bleeding

A 34-year-old Caucasian male presented at our Emergency epartment with severe abdominal pain of increase intenity and melena. Oesophagogastroduodenoscopy (EGDS) showed aemorrhagic gastritis, whereas ultrasonography demonstrated a yperechoic mass of 5 cm×5 cm in diameter located at the left liac fossa, apparently separated from the urinary bladder. Multietector CT angiography (MDCTA) confirmed the presence of a ound, well demarcated, non-homogeneous mass adjacent to the rinary bladder and to the small bowel (arrows, Fig. 1). There were o CT signs of invasion with regard to the surrounding adipose issue and the urinary bladder.

Hepatobiliary and Pancreatic: Malignant wash‐out pattern of hepatocellular cancer using dynamic MR imaging

The clinician now has a variety of different imaging options for the diagnosis of hepatocellular cancer. These include ultrasonography (US) with or without intravenous contrast, computed tomography (CT) with or without contrast, magnetic resonance (MR) with or without contrast and hepatic angiography. The usual screening test is high-resolution US that can permit the detection of hepatic lesions < 1 cm in diameter. If a focal lesion is detected or suspected, the next step is usually a contrast-enhanced CT or MR scan. Although the relative merits of these options are debated, some authors prefer MR scans using either gadolinium chelates or superparamagnetic iron oxide as the contrast agent. With the development of faster MR techniques, the entire liver can now be imaged in multiple phases of contrast enhancement including arterial, portal and delayed phases. Most reports have focussed on gadolinium-enhanced scans using T1-weighted images. The typical appearance of hepatocellular cancer is homogeneous or peripheral (rim) enhancement of the neoplasm. This can also be associated with an early ‘wash-out sign’ as illustrated below. These appearances reflect the fact that hepatocellular cancers are hypervascular, often with arterio-venous shunting, and derive most of their blood supply from the hepatic artery. The patient illustrated below was a 74-year-old man who was investigated because of epigastric discomfort and abdominal distension after meals. A US study showed a solid mass lesion in the left lobe of the liver. With a MR scan, there was a non-homogeneous mass lesion in the left lobe that measured 16 × 12 × 10 cm in size. The MR features were consistent with hepatocellular cancer in that the lesion was hypointense using T1-weighted images and hyperintense using T2-weighted images. There were also satellite lesions in the right lobe of the liver that showed similar intensity characteristics. After the administration of gadolinium, the lesions showed marked enhancement in the arterial phase when compared to the normal liver (Figure 1). In the late venous phase, the normal liver was enhanced but the lesions showed a ‘wash-out’ pattern that is typical for hypervascular lesions that are either primary or metastatic neoplasms (Figure 2). In this patient, a tru-cut biopsy confirmed the presence of hepatocellular carcinoma.

A Vanishing Cardiac Mass

Primary cardiac lymphoma is defined as a non-Hodgkin lymphoma involving only the heart and/or pericardium and is a rare malignancy.1 Patients may present with signs of heart failure, cardiac tamponade, or arrhythmias, depending on the site of the tumor.2 Prognosis is poor due to diagnostic delay and relevance of the site of disease. Case: “A 55-year-old man presented with a 2 month history of exertional chest pain, dyspnea, and recurrent fever. One month prior he also had evidence of a myocardial infarction with ST elevations and positive troponins. At time of admission his vital signs were stable. Transesophageal echocardiography was performed due to suspicion of bacterial endocarditis and showed huge bilateral atrial enlargement and a nonhomogeneous mass that distorted the atrial architecture. The mass externally compressed the superior and inferior vena cava and aortic arch, and infiltrated the right atria and pericardial space (Figure 1).” Endopericardial biopsy showed a subxiphoid approach confirmed large B-cell lymphoma. He was treated with external beam radiation (40 Gy) and CHOP chemotherapy (cyclophosphamide, doxorubicin, vincristine, and prednisone). Follow-up transesophageal echocardiography at 8 months showed no evidence of tumor (Figure 2).

Testicular Sertoli Cell Tumor in an Adult

Seongik Bang, Sang Don Lee From the Department of Urology, Pusan National University Yangsan Hospital, Pusan University College of Medicine, Busan, Korea Sertoli cell tumors of the testis are very rare and are usually benign. Here we report a case of a Sertoli cell tumor of the testis in a 46-year-old man. His chief complaint was a painless, palpable testicular mass that he had for 4 years. Serum levels of tumor markers were within normal limits. Testicular ultrasonography showed a 1.5 cm sized well-demarcated nonhomogeneous echogenic mass in the left testis. Chest x-ray and abdominopelvic CT showed no metastasis. Radical orchiectomy was performed. Histopathology showed a Sertoli cell tumor with no evidence of malignancy. (Korean J Urol 2009;50:300-302) 󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏󰠏

Chromophobe renal cell carcinoma with neuroendocrine differentiation

Chromophobe renal cell carcinoma was described by Thoenes et al. in 1986, and associations with carcinoma of collecting ducts, conventional renal cell carcinoma and sarcomatoid renal cell carcinoma have been described. We report a case of chromophobe renal cell carcinoma which showed neuroendocrine differentiation. This is the first known case to be clearly identified as such. The patient was a 56-year-old man with constant right flank pain and hematuria; CT scan revealed an 8.5 cm nonhomogeneous mass involving the right kidney. Right radical nephrectomy was performed. The tumor showed a mixture of classical and eosinophilic patterns of chromophobe cell carcinoma. Additionally, it showed insular, glandular and rosetoid-like formations embedded in a dense eosinophilic hyaline stroma. The cells were cuboid or cylindrical with well-defined boundaries, finely stippled chromatin and a small nucleolus. The appearance of the cytoplasm varied from faintly eosinophilic to coarsely granular eosinophilic. Immunohistochemically, the neuroendocrine areas were reactive for C-kit, epithelial membrane antigen, cytokeratin, cytokeratin 7, chromogranin A, neuron-specific enolase, CD56 and S-100 protein. Our case represents a typical chromophobe carcinoma with neuroendocrine differentiation. Additionally, the immunohistochemical profile in both types of lesion suggests a common origin from renal tubular cells.

Solar gravitational energy and luminosity variations

Due to non-homogeneous mass distribution and non-uniform velocity rate inside the Sun, the solar outer shape is distorted in latitude. In this paper, we analyze the consequences of a temporal change in this figure on the luminosity. To do so, we use the Total Solar Irradiance (TSI) as an indicator of luminosity. Considering that most of the authors have explained the largest part of the TSI modulation with magnetic network (spots and faculae) but not the whole, we could set constraints on radius and effective temperature variations. Our best fit of modelled to observed irradiance gives d T = 1.2 K at d R = 10 mas. However computations show that the amplitude of solar irradiance modulation is very sensitive to photospheric temperature variations. In order to understand discrepancies between our best fit and recent observations of [Livingston, W.C., Gray, D., Wallace, L., White, O.R., 2005. In: Sankarasubramanian, K., Penn, M., Pevtsov, A. (Eds.), Large-scale Structures and their Role in Solar Activity, ASP Conference Series, vol. 346. Astronomical Society of the Pacific, p. 353], showing no effective surface temperature variation during the solar cycle, we investigated small effective temperature variation in irradiance modeling. We emphasized a phase-shift (correlated or anticorrelated radius and irradiance variations) in the (d R, d T)-parameter plane. We further obtained an upper limit on the amplitude of cyclic solar radius variations between 3.87 and 5.83 km, deduced from the gravitational energy variations. Our estimate is consistent with both observations of the helioseismic radius through the analysis of f-mode frequencies and observations of the basal photospheric temperature at Kitt Peak. Finally, we suggest a mechanism to explain weak changes in the solar shape due to variation of magnetic pressure which modifies the granules size. This mechanism is supported by an estimate of the asphericity-luminosity parameter, w = −7.61 × 10 −3, which implies an effectiveness of convective heat transfer only in very outer layers of the Sun.

Primary Biliary B-Cell Lymphoma of the Cystic Duct Causing Obstructive Jaundice

A distinctive case of primary biliary lymphoma occurring in the cystic duct causing extrinsic compression of the porta hepatis in a 48-year-old woman is presented. Imaging studies revealed stricture of the common hepatic duct with a 2.5-cm nonhomogeneous mass at the porta hepatis, mimicking a Klatskin tumor. Exploratory laparotomy revealed a mass in the gallbladder neck with extension into the cystic duct akin to Mirizzi's syndrome. A soft, tan-yellow 1.0-cm mass was removed from the cystic duct, and infiltrating atypical lymphocytic nodules were identified with a final diagnosis of an anaplastic variant of diffuse large B-cell lymphoma.

Intraductal Papillary Cholangiocarcinoma Associated With von Meyenberg Complexes: A Case Report

Intraductal papillary cholangiocarcinoma (IPC) is a rare form of bile duct neoplasm with only 28 cases reported in the English literature to date. We report a rare case of an IPC arising in a liver containing many von Meyenberg complexes (VMC) in a 70-year-old woman. She presented with colicky right upper quadrant pain and nausea, mimicking biliary colic. Imaging studies showed a mass in the left lobe of the liver. A left hepatectomy, which included segments 2 and 3 was performed, and an ill-defined shiny polypoid nonhomogenous mass (8.2x2.9 cm) was identified within the lumen of a dilated bile duct without invading the liver parenchyma. Histologically, the tumor was composed of papillary fronds with fine fibrovascular cores lined by tall biliary columnar mucus secreting epithelium. Focally the cells were of the gastric foveolar type. The tumor extended into the peribiliary glands and merged with an adjacent large VMC. A possibility that the carcinoma may have originated in a VMC was considered. On follow-up after 12 months the patient is doing well and is without any disease or recurrence.

The change of solar shape in time and depth. Some consequences for space climate

During the last five years, studies of the Sun and Sun–Earth relationships have dramatically changed our view on solar terrestrial physics. We will here focus on new views on the solar interior. The internal non-homogeneous mass distribution and non-uniform angular velocity (function of the radial distance to the center and of the latitude) yield a complex outer shape. Beyond a “spherical” Sun is a new approach of solar-physics taking into account the gravitational energy which triggers the various layers. Such energy has been skipped in many ways up to now in theoretical models describing the solar output variability. In spite of many works on solar variations, there is not yet a consensus on the global experimental phenomenology. For instance, it is not yet known if this gravitational energy may explain faint observed irradiance variations, and the way the asphericity-luminosity parameter W acts on our stratosphere. Such issues must be solved to understand how the solar output variability may influence the Earth’s environment (helioclimatology). We will emphasize the key role of the subsurface layers (the leptocline, recently put in evidence by helioseismology) for a better prediction of the solar cycles. Regarding the solar core dynamics, the subject is of high priority for new investigations. We will conclude by giving some imprints on space-dedicated missions: GOLF-NG/DynaMICS in a joint effort with SDO (Solar Dynamics Observatory).

A large solitary fibrous tumor of the mediastinum

The patient was a 27一year—old woman with chest distress and short— ness of breath that suddenly started one month before her examina— tion.The symptoms were relieved with resting,SO she failed to go to the hospital for an examination.She had no complaints of fever, cough or hempotysis.One day,the symptoms became SO severe that she was sent to the emergency room and adiography disclosed an opaciW in her right hemithorax.A subsequent CT scan showed a 1arge.sharply delineated and nonhomogeneous mass in the iriferior fight middle mediastinum,which protruded to the right hemithorax. The mediastinal structure was apparently displaced to the left and the mass seemed to be adherent to the pleura,pericardium and adjacent large vessels(Fig.1A).There were enhancing areas peripheral to the mass after injecting the contrast material(Fig.1B).The 1eft side was shown to be normal.She was admitted to OUr hospital for further ex— amination on the same day. Her medical history was unremarkable except for being allergic to penicillin.She never smoked or drank alcohol,but she had been a worker spraying lacquer in a factory for about two years. Physical examination revealed regular BP(120/80 mmHg)and pulse (80 bpm).The expansion of thorax was symmetric.The breathing sounds were absent in the inferior site of the right lung.The 1eft was normal.and routine 1aboratory examination results were negative.Her blood glucose was 4.9 mmol/L and her B—HCG 1evel was 1ess than

Mitral valve thrombosis and infective endocarditis in a patient with prothrombin mutation

This report deals with a 25-year-old female patient, who was admitted to a medical centre with complaints of fatigue and arthralgia. A non-homogeneous mass originating from the posterior papillary muscle and reaching the posterior and anterior cusps of the mitral valve was evident on the patient’s echocardiogram. Her intractable fever, despite adequate antibiotic therapy, led us to consult with the cardiac surgeons.A mitral valve replacement was performed on the 8th day of admission.The pathological examination of the mitral valve and the vegetative lesion revealed the presence of organized thrombus and infective endocarditis.The patient had a history of oral contraceptive use for one year and at genetic examination we detected a heterozygous prothrombin mutation (G20210A). The association of infective endocarditis with native mitral valvular thrombosis in a case with prothrombin mutation and history of oral contraceptive use encouraged us to share our experience with our colleagues.

Pseudocyst formation after abdominal liposuction—extravasations of Morel–Lavallée on MR images

A swelling of the abdominal wall in a 27-year-old woman after undergoing liposuction is described. Pseudocyst of Morel-Lavallée was located within the abdominal fascia and removed by surgery. MRI showed a non-homogenous mass with hyper intense fluid level and septations in T2-weighted images. We speculated that MRI can be used to guide the treatment (conservative or surgical). The literature concerning liposuction is reviewed.