Use of a Conical Conducting Layer with an Electrical Impedance Probe to Enhance Sensitivity in Epithelial Tissues.

Tetra-polar electrical impedance measurement (TPIM) with a square geometry of electrodes is useful in the characterization of epithelial tissues, especially in the detection of cervical cancer at precancerous stages. However, in TPIM, the peak planar sensitivity just below the electrode surface is almost zero and increases to a peak value at a depth of about one third to one half of the electrode separation. To get high sensitivity for the epithelial layer, having thicknesses of 200 µm to 300 µm, the electrode separation needed is less than 1 mm, which is difficult to achieve in practical probes. This work proposes a conical conducting layer in front of a pencil like probe with a square geometry of TPIM electrodes to create virtual electrodes with much smaller separation at the body surface, thus increasing the sensitivity of the epithelial tissues. To understand the improvements, if any, 3D sensitivity distribution and transfer impedance were simulated using COMSOL Multiphysics software for a simplified body tissue model containing a 300 µm epithelial layer. It has been shown that fractional contribution of an epithelial layer can be increased several times placing a cylindrical conducting layer in between the tissue surface and the electrodes, which can further be enhanced using a conical conducting layer. The results presented in this paper can be used to choose an appropriate electrode separation, conducting layer height and cone parameters for enhanced sensitivity in the epithelial layer.

Biofilter for generation of concentrated sulphuric acid from H2S.

Biofilters are used for the conversion of odorous hydrogen sulphide to odourless sulphate in wastewater treatment plants under the right conditions of moisture and pH. One of the consequences of maintaining the suitable pH and moisture content is the production of large volumes of weakly acidic leachate. This paper presents a biofilter with a maximum H2S elimination capacity of 16.3 g m(-3) h(-1) and removal efficiency greater than 95 % which produces small volumes (1 mL of solution L(-1) of reactor day(-1)) of sulphuric acid with a concentration greater than 5.5 M after 150 days of continuous operation. The concentrated sulphuric acid was produced by intermittently trickling a minimum amount of nutrient solution down the upflow biofilter which created a moisture and pH gradient within the biofilter resulting in an environment at the top for the bacterial conversion of H2S, while sulphuric acid was accumulated at the base. Genetic diversity profiling of samples taken from different sections of the biofilter confirms that the upper sections of the biofilter had the best environment for the bacteria to convert H2S to sulphate. The formation of concentrated sulphuric acid presents an opportunity for the recovery of sulphur from the waste stream as a usable product.

A Rare Internal Herniation in Adult: Meckel's Diverticulum.

Intestinal obstruction due to Meckel's diverticulum is the most common presentation in adults. There are various mechanisms by which it can cause intestinal obstruction such as volvulus of small intestine around a fibrous band extending from Meckel's diverticulum to umbilicus, intussusception, and Littre's hernia. We report the case of a young adult operated on emergency for acute intestinal obstruction. The CT scan suggested a nonspecific internal herniation. Surgical exploration confirmed a rare type of obstruction due to Meckel's diverticulum.

Classification of breast tumour using electrical impedance and machine learning techniques.

When a breast lump is detected through palpation, mammography or ultrasonography, the final test for characterization of the tumour, whether it is malignant or benign, is biopsy. This is invasive and carries hazards associated with any surgical procedures. The present work was undertaken to study the feasibility for such characterization using non-invasive electrical impedance measurements and machine learning techniques. Because of changes in cell morphology of malignant and benign tumours, changes are expected in impedance at a fixed frequency, and versus frequency of measurement. Tetrapolar impedance measurement (TPIM) using four electrodes at the corners of a square region of sides 4 cm was used for zone localization. Data of impedance in two orthogonal directions, measured at 5 and 200 kHz from 19 subjects, and their respective slopes with frequency were subjected to machine learning procedures through the use of feature plots. These patients had single or multiple tumours of various types in one or both breasts, and four of them had malignant tumours, as diagnosed by core biopsy. Although size and depth of the tumours are expected to affect the measurements, this preliminary work ignored these effects. Selecting 12 features from the above measurements, feature plots were drawn for the 19 patients, which displayed considerable overlap between malignant and benign cases. However, based on observed qualitative trend of the measured values, when all the feature values were divided by respective ages, the two types of tumours separated out reasonably well. Using K-NN classification method the results obtained are, positive prediction value: 60%, negative prediction value: 93%, sensitivity: 75%, specificity: 87% and efficacy: 84%, which are very good for such a test on a small sample size. Study on a larger sample is expected to give confidence in this technique, and further improvement of the technique may have the ability to replace biopsy.

[Perineal-scrotal gangrene: epidemiological and therapeutic aspects. About 45 cases]. / La gangrène périnéoscrotale: profil épidémiologique et aspects thérapeutiques. À propos de 45 cas.

Perineoscrotal gangrene is an acute disease, a rare and severe affection of the perineum, whose evolution is unpredictable and rapidly extensive. The diagnosis is clinical. The paraclinical examinations allow early diagnosis and assessment of anatomical and biological repercussions. We conducted a retrospective study of 45 patients spread over six years, involving a multidisciplinary team consisting of three specialists (urologists, visceral, plastic surgeons). The average age was 52 years. The largely male dominated our series. Fournier gangrene was the most common etiology. We noted five cases of death (11%) in the acute phase, secondary to septic shock (four patients) or multiple organ failure (one patient). The evolution was favorable in 40 other patients in the series, requiring an initial management in intensive care unit, and surgical treatment. The average hospital stay was 17 days. After the acute phase, all patients underwent a surgery for skin coverage, ranging from guided healing (two patients) to musculocutaneous flap of the gracilis (six patients) via the secondary suture (four patients), the burying the testes (18 patients) and half thick skin graft, with a functional and aesthetic result was acceptable, and minimal sequelae. In our series, the most predictive prognostic factors would be the delay of care, sepsis on admission and associated diseases.

Adult intussusception caused by an inflammatory fibroid ileal polyp.

BACKGROUND: Inflammatory fibroid polyps (IFPs) are rare benign lesions of uncertain origin that may occur in various parts of the gastrointestinal tract that originate from the sub mucosa located in different sites of the digestive tract. They are commonly located in the stomach and small bowel. It is one of the probable diagnoses that should be considered in obstructive tumors of the small intestine causing invagination. METHODS: A case of IFP is presented, causing intestinal invagination in an 39-year-old female patient, admitted with abdominal distension and pain. RESULT: Computerised tomography imaging (CT) demonstrated intussusception of the small bowel. Exploratory laparotomy revealed a bowel intussusception. An ileo-ileal anastomosis was performed after resection of the tumoral segment. Histology of the resected small bowel revealed an inflammatory fibroid polyp. CONCLUSIONS: intussusception secondary to IFPs of the small intestine are difficult to diagnose without recognition of its clinical and pathological characteristics. CT is useful in confirming an anatomical abnormality, histological examination establishes the final diagnosis of IFPs.

Mesenteric appendicitis strangulating small bowel: an exceptional internal herniation.

Primitive internal hernias are a rare cause of intestinal obstruction. They are often paraduodenal even transmesocolic, but only rarely transomental. We present a rare case of an internal abdominal hernia in a young man. The small bowel was strangulated by an intra mesenteric appendicitis. This hernia was revealed by abdominal pain, nausea and vomiting. Plain X-ray of the abdomen showed dilated jejunal and ileal loops with multiple air-fluid levels. The diagnosis of appendicitis was suggested by ultrasound but the internal hernia was found only upon surgical exploration. An appendicectomy and adhesiolysis were performed. The patient recovered fully after 3 days, and had an uneventful postoperative course. The authors discuss the possible cause of this rare intestinal obstruction.

Primary pelvic hydatid cyst an unusual cause of cystic adnexal image (mass).

Hydatid cyst is a parasitic human infection which is endemic in North Africa. It is more frequently localized in the liver and the lung. Involvement of others sites is usually secondary to these primary localizations. We report 2 exceptional cases of primary pelvic hydatid cyst diagnosed respectively in a 37-year-old and in a 48-year-old women. These cases will focus on the different characteristics of the infection, and the benefit of including epidemiologic arguments in using the diagnostical approach of adnexal masses.

Transmesocolic internal herniation: a rare case of small bowel obstruction, "the Marrakesh hernia".

Internal hernias, including paraduodenal (traditionally the most common), pericecal, foramen of Winslow, and intersigmoid hernias, account for approximately 0.5-5.8% of all cases of intestinal obstruction and are associated with a high mortality rate, exceeding 50% in some series. We report an extremely rare case of an internal abdominal hernia, through the right mesocolon, in a young woman with a right colon with no peritoneal fixation. This hernia was revealing by abdominal pain, nausea, and vomiting. The diagnosis of internal hernia was suggested by computed tomography (CT), but the exact type of internal hernia was confirmed by surgical exploration. The postoperative course was uneventful and the patient fully recovered after 3 days. The patient is free from symptoms and from recurrence, after 12 months of follow-up.

A modified formula for defining tissue phantom ratio of photon beams.

Tissue phantom ratio (TPR), for square fields of various dimensions has been determined at varying depths in water. The dose in water has been measured at a fixed source-to-surface distance (SSD) of 100 cm and reference depth of 5 cm for 6 MV photon beam of Siemens Linear Accelerator Primus 11 in German Cancer Research Center (DKFZ), Heidelberg, Germany. A modified formula has been developed to calculate the TPR value for isocentric treatment. The present article describes the conversion of the measured data values into a comprehensive and consistent data set by the modified formula, that gives the TPR from Percentage Depth Dose (PDD) with depth as a function of field sizes from 10 mm x 10 mm upto 300 mm x 300 mm) and depth (from 0 mm to 300 mm).

Pulsed electromagnetic fields for the treatment of bone fractures.

The effectiveness of electrical stimulation and Pulsed Electro Magnetic Field (PEMF) stimulation for enhancement of bone healing has been reported by many workers. The mechanism of osteogenesis is not clear, therefore, studies look for empirical evidence. The present study involved a clinical trial using low amplitude PEMF on 19 patients with non-union or delayed union of the long bones. The pulse system used was similar in shape to Bassett's single pulse system where the electric voltage pulse was 0.3 mSec wide repeating every 12 mSec making a frequency of about 80 Hz. The peak magnetic fields were of the order of 0.01 to 0.1 m Tesla, hundred to thousand times smaller than that of Bassett. Among the 13 who completed this treatment schedule the history of non-union was an average of 41.3 weeks. Within an average treatment period of 14 weeks, 11 of the 13 patients had successful bone healing. The two unsuccessful cases had bone gaps greater than 1 cm following removal of dead bone after infection. However, use of such a low field negates Bassett's claim for a narrow window for shape and amplitude of wave form, and justifies further experimental study and an attempt to understand the underlying mechanism.