Vortex sound due to a flexible boundary backed by a cavity in a low mach number mean flow

Low frequency sound radiated due to the unsteady motion of an inviscid vortex in the proximity of a flexible membrane backed by an airtight cavity on an otherwise rigid plane is investigated theoretically. Results show that both monopole and dipole are created but the latter is important only when the vortex is traversing over the membrane. The monopole results from the membrane vibration and the dipole from the transverse motion of the vortex. It is also found that these sound fields tend to counteract each other. The increase in the mean flow speed in general results in a stronger acoustic power radiation, but sound attenuation may be possible if the membrane-cavity system is weak compared with the mean flow momentum.

Sound generated by vortices in the presence of a porous half-cylinder mounted on a rigid plane

The sound generated by a single vortex and by two identical vortices in the presence of a half-cylinder made of porous material mounted on a rigid horizontal plane is studied theoretically using the acoustic analogy and the matched asymptotic expansion method. Both longitudinal and transverse dipoles are observed upon the introduction of the porous cylinder, but the former is considerably stronger than the latter in all the cases studied. Results suggest that the amplitudes of the dipoles and the overall acoustical energy radiated can be higher than that in the rigid cylinder case under some suitable combinations of flow parameters, especially when the flow resistance inside the porous material seen by the vortices is very small.

Noise screening effects of balconies on a building facade

The insertion loss and its spectrum due to a rectangular balcony on a building facade in the presence of sound reflection and scattering from adjacent balconies were examined using a scale model. The front panel of the balcony dictates the screening performance, while the side walls of the balcony are found to be insignificant. Balconies without a front panel do not provide acoustic protection in the presence of upper balcony reflection, especially for a distant noise source. Sound amplifications are also observed in many cases. In addition, the shapes of the insertion loss spectra are found to depend on the elevation angle of the balcony. Significant correlations between the A-weighted balcony insertion losses with this angle are found in the absence of upper balcony reflections. With such reflection, an angle defined using the balcony configuration and source position correlates within engineering tolerance to the insertion losses.

Sound transmission across duct constrictions with and without tapered sections

The sound power transmission loss across duct constrictions with linearly tapered sections is studied with the finite element method. Results show that the acoustic energy distributions of transmitted waves at high frequency depend critically on the exit configuration of the constriction. The corresponding strengths of these waves are very much affected by the entrance setup of the constriction. The difference between inlet and outlet impedance of a constriction leads to weaker resonant sound transmission.

Treatment results of endometrial carcinoma with positive peritoneal washing, adnexal involvement and serosal involvement

AIMS

To review the treatment results of patients with endometrial carcinoma having positive peritoneal washing (PPW), adnexal involvement, uterine serosal involvement, or all three.

MATERIALS AND METHODS

The treatment records of patients who had undergone primary surgery for endometrial cancer without distant metastasis during 1990--2001 at the Department of Clinical Oncology, Tuen Mun Hospital, Hong Kong, were reviewed. Thirty-five patients were found to have involvement of positive PPW, adnexal involvement, uterine serosal involvement, or all three. Seven (20%) of them had gross or microscopic lymph-node metastasis. Thirty-three (94.3%) patients received adjuvant radiotherapy (28 whole-pelvic irradiation [WPI]; five abdominal radiotherapy [WART]). Two patients with solitary ovarian metastasis received chemotherapy, and one with isolated PPW also received adjuvant hormonal therapy. The median follow-up was 50.4 months (range 2.4-151.2 months). Multivariate analysis was carried out using the Cox regression proportional hazards model.

RESULTS

Among the 28 patients with clinical or pathological node-negative disease (International Federation of Gynecology and Obstetrics [FIGO] stage IIIA), only two patients with solitary ovarian metastases developed recurrence. The 5-year actuarial disease-free survival (DFS) rates for the whole group and patients without lymph-node involvement were 77.9% and 91.7%, respectively. Five out of the seven patients with lymph-node involvement developed recurrences. Univariate analysis showed that lymph-node involvement (P < 0.0001) and high-grade disease (P = 0.011) were the significant poor prognostic factors. Multivariate analysis showed that lymph-node involvement was the only significant poor prognostic factor to predict poor 5-year DFS (P = 0.0001). Only one patient (3.7%) who had received WART developed grade 4 toxicity.

CONCLUSIONS

This study showed that good treatment results could be obtained from patients with stage IIIA endometrial carcinoma without clinical or pathological lymph-node involvement after adjuvant radiotherapy, with acceptable late side-effects. The relative prognostic importance of individual IIIA involvement and the optimal adjuvant treatment remain to be determined.

Sound transmission characteristics of Tee-junctions and the associated length corrections

The sound transmission characteristics of a Tee-junction formed by a sidebranch and an infinitely long duct are investigated numerically using the finite element method. The associated corrections of the branch length and the upstream duct length are also discussed in detail. The types of branch resonance that result in strong or weak sound transmission across the junction are determined and their effects on the length corrections examined. Results suggest that the type of sidebranch, the branch width, the branch length, and the order and the form of the resonance affect more significantly the length corrections of the duct section. The excitation of nonplanar higher branch modes gives rise to rapid increase in the duct length corrections and also results in lower sound transmission.

Isolated foot ulcer complicating acute leukemia: an unusual manifestation of herpes simplex virus infection simulating pyoderma gangrenosum

An isolated foot ulcer developed in a child with newly diagnosed acute mixed lineage leukemia during induction chemotherapy. Despite its clinical resemblance to pyoderma gangrenosum, herpes simplex virus infection was eventually diagnosed on histopathology. Treatment with oral acyclovir was ineffective, but the ulcer healed with intravenous acyclovir followed by oral valaciclovir. Viral infection remains an unusual but important cause of isolated extragenital cutaneous ulceration in the immunocompromised child.

On low frequency sound transmission loss of double sidebranches: a comparison between theory and experiment

The sound power transmission losses of various sidebranches installed along a rectangular duct below the first cut-off frequency of the duct are studied experimentally. Special efforts are made to examine how accurately the plane-wave theory predicts the sound-power transmission loss. Four types of sidebranch impedance are established and their effects to the sound power transmission loss discussed. It is found that under the nonresonant conditions the plane-wave theory can give reasonable prediction when the branch separation is large or the original sound transmission loss of the corresponding single side-branch is weak. The theory always overestimates the sound transmission loss at resonant conditions but gives underestimation if the transmission loss is due to the noise breakout in the sidebranches, especially for short branch separation.

Sound transmission across a smooth nonuniform section in an infinitely long duct

Sound transmission across a nonuniform section in an infinite duct is studied numerically using the finite element method. An impedance matched absorptive portion is added to each end of the computational domain so as to avoid the undesirable higher mode reflection that will otherwise take place there. Results suggest that the sound fields downstream of the nonuniform section inlet are complicated and cannot be easily described by the conventional solution of the wave equation. The distribution of acoustic energy among the various propagating modes well downstream from the outlet of the nonuniform section is also discussed. Results show that the first symmetrical higher mode is important for all cases. The plane wave becomes important at high frequency with high rate of change of the cross-sectional area when the section is a convergent one.

Vortex sound generation due to a flow impedance discontinuity on a flat surface

The sound generated by the unsteady motion of a vortex filament moving over a flat boundary with a sharp flow impedance discontinuity is studied theoretically. Theoretical results show that the vortex filament undergoes significant accelerating or decelerating motions and radiates sound at the instant when it moves across the plane of impedance discontinuity. The accelerations and decelerations of the vortex filament are shown to be the major mechanisms of sound generation. The sound so produced has a large low-frequency content such that the change in the flow impedance affects only the sound generation process but not the subsequent sound propagation to the far field.

Performance of noise indices in air-conditioned landscaped office buildings

Noise measurements and a questionnaire survey were carried out in air-conditioned landscaped offices in the present study in an attempt to find out what existing noise index gives the best correlation with the auditory sensation feeling of office workers. Results from statistical analyses show that the Equivalent Sound Pressure LEvel is the best among the 14 commonly used noise indices for this purpose. It is also found that the less commonly used Zwicker's loudness level performs better than the commonly adopted Noise Criterion curves and Noise Rating curves in predicting auditory sensation of office workers in air-conditioned landscaped offices. The performance of the 14 noise indices in predicting auditory comfort are compared.

Paucicellular variant of anaplastic thyroid carcinoma. A mimic of Reidel's thyroiditis

Anaplastic thyroid carcinomas usually pose no problems in histologic diagnosis because of the obvious invasive growth, high cellularity, and frank anaplasia. Two cases of a variant of anaplastic thyroid carcinoma with peculiar gross and histologic features closely mimicking those of Riedel's thyroiditis are described in this report. The clinical features were no different from those of the usual anaplastic thyroid carcinomas: occurrence in elderly subjects, presentation with rapidly enlarging neck mass associated with compression symptoms, and rapidly fatal outcome. The tumors were infiltrative, hard, fibrotic masses that partly or completely replaced one lobe of the thyroid, and extended to perithyroid tissues. Histologically, they were predominated by acellular fibrous or infarcted tissue with central dystrophic calcification, as well as hypocellular foci comprising mildly atypical spindle cells intermingled with collagen and small lymphocytes. Both cases showed permeation and plugging of the arteries by tumor. Lymph node metastasis was documented in one case. The spindle cells were positive for epithelial membrane antigen in both cases, and cytokeratin in one. The qualifying term "paucicellular variant" accurately describes this uncommon morphologic variant of anaplastic thyroid carcinoma. It is important to recognize this variant so as not to mistaken it for Riedel's thyroiditis, which is a reactive condition with a very favorable prognosis. The distinguishing features are as follows: presence of infarction, atypical cells in at least some areas, atypical spindle cells obliterating large blood vessels, and immunoreactivity for epithelial markers.

An unusual variant of lobular breast carcinoma. A case report

A case of the solid variant of lobular carcinoma of the breast occurred. The cytologic findings are discussed, with particular reference to the resemblance to non-Hodgkin's lymphoma.

Hepatocellular carcinoma metastasizing to the brain and orbit: report of three cases

Hepatocellular carcinoma rarely metastasizes to the brain or orbit. We report 3 clinically manifest examples, one of which occurred in a 13-yr-old boy. In 2 cases the intracranial metastasis was the initial presenting lesion. The 2 cases of brain metastasis both presented with intracerebral hemorrhage. Light microscopic examination of these tumors revealed a trabecular hepatocellular carcinoma of Edmondson grade II with focal hemorrhage and necrosis. Their immunohistochemical profile was identical to that described for primary hepatocellular carcinoma. The differential diagnosis from other intracranial metastatic tumors is discussed.

Follicular dendritic cell tumors of the oral cavity

Follicular dendritic cell tumors are uncommon, and all the reported cases have occurred as primary lymph node tumors. We report two cases in the oral cavity, one in the soft palate and one in the tonsil. The tumors were characterized by sheets, whorls, and storiform arrays of spindly and syncytial-appearing cells with oval nuclei, fine chromatin, distinct nucleoli, and occasional nuclear pseudoinclusions. Multinucleated forms were present and were prominent in one case. An unusual feature was the presence of irregular pseudovascular spaces, which could raise a concern for vascular neoplasm. Because the tumors showed cohesive growth and a sharp interface with the fibrous stroma, they could also be mistaken for carcinoma, sarcoma, or melanoma. After radiation therapy, the palatal tumor showed a greater degree of nuclear pleomorphism, numerous nuclear pseudoinclusions, and striking nuclear grooving and foldings, mimicking interdigitating reticulum cell tumors. The diagnosis in both cases was confirmed by immunoreactivity with CD21 and CD35 and by ultrastructural demonstration of interdigitating cell processes with desmosomes. Both tumors also showed unexpected immunoreactivity with muscle-specific actin. Follicular dendritic cell tumor merits wider recognition of its possible extranodal occurrence as well as its full morphological spectrum in order to better define its behavior.

Mallory's bodies in placental site nodule

We report two cases of placental site nodule in which Mallory's bodies were found in the intermediate trophoblasts constituting the lesion. Mallory's bodies are known to occur in hepatocytes and pulmonary alveolar cells in a wide variety of conditions, and represent abnormal cytoplasmic aggregates of cytokeratin intermediate filaments. Their occurrence outside the liver and lung is exceptional. In the present cases, they were immunoreactive for both low- and high-molecular-weight cytokeratins. Since high-molecular-weight cytokeratin is not normally expressed in intermediate trophoblasts, the formation of Mallory's bodies appears to involve aberrant expression of cytoskeletal proteins.

Fine-needle aspiration of cystic nephroma (multilocular cyst of the kidney)

Cystic nephromas are rare tumors of the kidney most commonly affecting boys or adult females. The fine-needle aspiration cytomorphology has not yet been described. A renal cystic mass in a 56 year old female was aspirated under ultrasound guidance. Papanicolaou stained smears of the cyst fluid revealed markedly atypical cells forming papillary clusters. Subsequent nephrectomy showed a typical cystic nephroma with lining epithelium resembling that seen in the aspirate. The cytomorphology of cystic nephroma has been misdiagnosed as renal cell carcinoma in the literature. Low cellularity, absence of necrosis, and paucity of single cells are features that should raise the possibility of cystic nephroma in a cystic renal mass.

Central nervous system lymphoma: primary lumbar nerve root infiltration

Primary malignant lymphoma of the central nervous system (CNS) is rare and only infrequently involves the spinal cord, usually in association with multifocal CNS spread. We report a case of primary lymphoma infiltrating lumbar nerve roots without evidence of systemic lymphoma. There has been an excellent response to combined modality therapy, comprising radiotherapy with intrathecal and intravenous cytotoxics. The patient remains well and active 22 months after diagnosis. The literature regarding these rare tumors is reviewed.

Growth and antigenic characteristics of basal cell carcinoma in culture

Basal cell carcinomas (BCCs) were cultured using an explant method and compared with normal cultured skin. Immunohistochemical staining revealed reduced beta 2 microglobulin uptake by BCCs in frozen section, but normal staining of the tumours in culture. In culture, fibronectin was detected on the cell surface of normal keratinocytes but not on BCCs. The above differences may explain some of the behaviour of BCCs in vivo.