Observation of heterodyne mixing in surface x-ray photon correlation spectroscopy experiments

We report measurements of propagating capillary waves on a liquid water surface at T=5 degrees C with x-ray photon correlation spectroscopy. The experiment has been performed under grazing incidence conditions with an incoming x-ray beam below the critical angle of total external reflection. In the q region investigated the measured intensity-intensity autocorrelation functions of the liquid water surface were found to be heterodyne signals, i.e., a combination of first- and second-order correlation functions g(1)(tau) and g(2)(tau).

Effect of lead on growth and nitrate assimilation of Vigna radiata (L.) Wilczek seedlings in a salt affected environment

The inhibition of seedling growth and nitrate reductase activity in 5 d old Vigna radiata (L.) Wilczek cv. Pusa Baisakhi in the presence of 1.0 mM lead acetate increased drastically, if NaCl (6 and 12 EC) was also present in the nutrient media along with the metal salt. Correspondingly higher endogenous Na+ levels were accumulated in the roots and leaves of seedlings in presence of the two stresses. On the other hand, the levels of endogenous lead get reduced in presence of NaCl in both the roots and leaves. Roots accumulated more Pb2+ and Na+ than the leaves. The two stresses affect more drastically in the additive or even synergistic manner during the early growth phase of the seedlings.

Utility of Y-Chromosome Short Tandem Repeat Haplotypes in Forensic Applications

Patrilineally transmitted Y-chromosomal markers have been shown to resolve forensic cases under certain scenarios where autosomal markers provide limited or inconclusive evidence. Several Y-short tandem repeat (Y-STR) loci have been validated for forensic use, and Y-STR haplotype databases for a number of geographic locations are now available in the literature and online. In this review, examples are presented of situations where Y-STR loci can provide valuable supplemental forensic evidence when autosomal STR loci fail or provide little evidence. Also, different methods of interpreting Y-STR forensic evidence in casework analysis are outlined, suggesting that in spite of excessive conservativeness, the counting method is still the most simple and easily defensible method of interpreting Y-STR forensic evidence. While the need for developing more powerful interpretation methods should be considered, it is stressed that expansion of Y-STR databases should focus on increasing sample sizes and the inclusion of more anthropologically defined populations to improve the efficiency of interpretation of Y-STR markers in forensic applications.

Forensic Casework Applications Using Y-PLEX™ 6 and Y-PLEX™ 5 Systems

Analysis for Y-chromosome short tandem repeat (Y-STR) loci has become a useful tool in resolving difficult cases, particularly with evidence samples containing mixtures of male and female DNA. The Y-PLEX™ 6 and Y-PLEX™ 5 systems have been validated and used in forensic cases. A total of 188 samples, which included 127 evidence samples, have been analyzed using Y-PLEX™ 6 and Y-PLEX™ 5 systems. The evidence sample types included fingernails, sperm, epithelial cells, blood, and tissue. The results from five cases are discussed. The results from Y-PLEX™ 6 kits have accepted in several jurisdictions throughout the United States.

Pericardial synovial sarcoma

A 29-year-old young man presented with acute breathlessness. After investigative work-up he was found to have a massive pericardial tumour. Thoracotomy and near total surgical excision of the pericardial tumour was carried out. Histopathology and immunohistochemical markers study revealed it to be a synovial sarcoma arising from the left lateral pericardial surface. Postoperatively, he received external radiation and chemotherapy. Thirteen months after surgery he developed local recurrence which was unresectable.

X-ray scattering from freestanding polymer films with geometrically curved surfaces

We show that the x-ray surface scattering from a freestanding polymer film exhibits features that cannot be explained by the usual stochastic formalism for surfaces with random height fluctuations. Instead, a geometric description of the film morphology assuming two curved surfaces characterized by a radius of curvature and a lateral cutoff length successfully accounts for the phase difference between the Kiessig fringes of the nominal "specular" and "off-specular" components of the scattering. The formalism allows one to distinguish unambiguously between conformal and anticonformal curvature morphologies at long length scales.

Surface dynamics of polymer films

The dynamics of supported polymer films were studied by probing the surface height fluctuations as a function of lateral length scale using x-ray photon correlation spectroscopy. Measurements were performed on polystyrene (PS) films of thicknesses varying from 84 to 333 nm at temperatures above the PS glass transition temperature. Within a range of wave vectors spanning 10(-3) to 10(-2) nm(-1), good agreement is found between the measured surface dynamics and the theory of overdamped thermal capillary waves on thin films. Quantitatively, the data can be accounted for using the viscosity of bulk PS.

Effect of external electrical field on mobile water fraction and physiological processes in wheat (Triticum aestivum) leaves

Experiments were conducted to study the effect of external electric field on physiological processes, moisture content and mobile water fraction in wheat leaves. Application of electric field increased the stomatal resistance immediately and it continued to increase upto 10 min. Photosynthesis and respiration of leaves decreased with the application of external electric field. Leaf moisture content and mobile fraction of water measured as relaxation times were marginally increased with electric field. Closure of stomata, in spite of maintaining higher leaf moisture content of the leaf with external electric field, suggested that electric field might have regulated stomatal movement through hormones or ion flux across the cells.

Momentum-resolved charge excitations in a prototype one-dimensional mott insulator

We report momentum-resolved charge excitations in a one-dimensional (1D) Mott insulator studied using high resolution inelastic x-ray scattering over the entire Brillouin zone for the first time. Excitations at the insulating gap edge are found to be highly dispersive (momentum dependent) compared to excitations observed in two-dimensional Mott insulators. The observed dispersion in 1D cuprates ( SrCuO2 and Sr2CuO3) is consistent with charge excitations involving holons which is unique to spin-1/2 quantum chain systems. These results point to the potential utility of momentum-resolved inelastic x-ray scattering in providing valuable information about electronic structure of strongly correlated insulators.

Study of primary amenorrhoea with special reference to cytogenetic evaluation

An attempt has been made to find out the proportion of genetic causes in cases of primary amenorrhoea and to analyse different chromosomal pattern. Cases were analysed according to clinical profile, X-ray, laparoscopy/pneumography, hormone profile, USG, Gonadal Biopsy and Cytogenetic study including Sex Chromatin (Barr body) and Karyotyping. Among the 72 cases studied, the aetiological factors were Mullerian duct abnormalities in 27 cases (37.5%) Gonadal agenesis in 13 cases (18.05%). Turner stigmata in 18 cases (25%), Y cell line in 6 cases (8.33%). Delayed menarche in 4 cases (5.55%), systemic disease like Tuberculosis and Idiopathic 2 cases (2.77%) each. Chromosomal aberration was seen in 24 cases (33.33%) and it comes second most common cause of primary amenorrhoea after mullerian duct abnormalities.

Minor salivary glands: causing major problems

Tumours arising in the parapharyngeal space (PPS) are rare and account for approximately 0.5% of all head and neck neoplasms. These neoplastic processes represent a wide variety of both benign (80%) and malignant lesions arising from the diverse range of structures within and surrounding the PPS. The PPS is typically conceptualized as a potential neck space in the shape of an inverted cone with its base at the skull base and apex at the greater cornu of the hyoid. Because of this unique structure, lesions must often grow to a considerable size before symptoms become apparent and clinical detection is possible. A rare case of mucoepidermoid tumour of the minor salivary glands arising in the prestyloid parapharyngeal space is described. The complex anatomical and pathological considerations within this region present a substantial challenge to the head and neck surgeon in the evaluation and management of these lesions.

Volume-controlled ventilation. Variations on a theme

Development of sophisticated transducers and microprocessor-based ventilators now enables the performance of volume-controlled ventilation of newborn infants. Volume-controlled modes include standard intermittent or synchronized intermittent mandatory ventilation; assist-control ventilation; and hybrid modes, such as pressure-support ventilation, pressure-regulated volume-control ventilation, volume-assured pressure support, and volume guarantee. This article describes the concepts and clinical applications of these ventilatory modes.

Newer modes of mechanical ventilation for the neonate

For decades, the overwhelming majority of infants requiring mechanical ventilation for respiratory failure were treated with standard time-cycled, pressure-limited intermittent mandatory ventilation. Technologic advances in the 1990s brought forth sophisticated transducers and microprocessor-based mechanical ventilators that enabled implementation of many newer modes of mechanical ventilation. Some of these are volume-targeted rather than pressure-targeted, and many allow an element of patient control of the ventilator, including initiation and termination of inspiration and control of flow. Some modes are even hybrids, combining the best features of both pressure-targeted and volume-targeted modes. This article reviews the principles and salient clinical features of the newer ventilatory modes for newborns with respiratory failure.

Poor agreement in recognition of abnormal mitoses: requirement for standardized and robust definitions

AIMS

The finding of abnormal mitoses is a helpful feature in differentiating between benign and malignant neoplasia and has prognostic significance for some tumours. As the use of a histopathological variable is limited by the reproducibility of its recognition, we tested the interobserver agreement in the classification of abnormal mitoses among histopathologists. METHODS adn

RESULTS

Ten practising histopathologists were shown 30 potential mitotic figures and were asked to classify these as 'normal mitoses', 'abnormal mitoses' or 'not mitoses' according to the criteria each pathologist used in their routine practice. The results were analysed using kappa statistics. Overall agreement was only fair with a combined kappa of 0.31 and there was unanimous categorization of only four of 30 test items, none of which was called abnormal. The poorest result was obtained for the category 'abnormal mitosis' with only slight agreement (kappa 0.19). Agreement for the other categories varied from moderate (kappa = 0.45) for 'not a mitosis' to fair (kappa = 0.26) for 'normal mitosis'. Comparison of the results for observer pairs showed that for 12 out of the 45 possible pairings, there was no more agreement than might be expected by chance alone.

CONCLUSION

Agreement is poor among practising histopathologists in the recognition of abnormal mitoses. A standardized and robust definition is needed if diagnostic and prognostic significance is accorded to the finding of an abnormal mitosis in the context of neoplasia.

Detection and correction of a migration anomaly on a 310 genetic analyzer

During STR analysis on the 310 Genetic Analyzer, retarded migration of GS500ROX size standards and alleles in some samples was observed. The contribution of reagents, capillary and performance optimized polymer POP 4 to the observed anomaly was experimentally eliminated. Variation in electrophoresis temperature between 55 degrees C and 65 degrees C did not alter the rate of migration of GX500ROX size standard and sample alleles. An eroded connector for the cathode mounted on the heat plate assembly caused the abnormal migration. Hence, it is important to verify the mobility of all fragments in the size standard for each sample to avoid any erroneous allele calls by the automated data analysis software.

Robinow syndrome

Robinow syndrome is a rare congenital abnormality. It is characterized by mesomelic brachymelia, hemivertebrae, dysmorphic facies, genital hypoplasia, micropenis, clinodactyly, camptodactly, hypoplastic nails and moderate short stature. We are documenting the case on the account of its rarity and additional features.

Endoscopic dilation for treatment of anastomotic leaks following transhiatal esophagectomy

BACKGROUND AND STUDY AIMS

Anastomotic leak is a known complication after transhiatal esophagectomy (THE) and cervical esophagogastric anastomosis. Conservative management takes a long time to heal such leaks. We assessed the role of endoscopic dilation in patients with anastomotic leak following THE.

PATIENTS AND METHODS

Eight consecutive patients (seven men, one woman; mean age 51) with anastomotic leak following THE were subjected to endoscopic dilation using Savary Gilliard dilators of 7-15 mm diameter. The mean interval between surgery and detection of leak was 9 days (range 5-22 days) and dilation was performed at a mean interval of 11.4 days (range 1-20 days) after detection of the leak.

RESULTS

Drainage from fistulas stopped completely after 1-8 days (mean 3 days). X-ray with water soluble contrast showed closure of the fistula in all cases. Duration of follow-up ranged from 2 to 12 months. Anastomotic strictures developed in three patients. These patients required three sessions each of repeat dilation, and were alive at follow-up periods of 2, 4, and 12 months, respectively. One patient developed recurrence of growth at an anastomotic site. Four patients died because of distant metastasis.

CONCLUSIONS

Bougie dilation of anastomotic sites is a safe and effective technique for the healing of anastomotic leaks following THE. However there is a need for a prospective randomized trial comparing endoscopic dilation with no dilation in patients with anastomotic leaks following THE.

Budd-Chiari syndrome: our experience of 71 patients

BACKGROUND

Hepatic venous outflow obstruction (Budd-Chiari syndrome) is frequently encountered as a cause of portal hypertension at our centre.

METHODS AND RESULTS

We studied the clinical presentation, therapeutic modalities and outcome of 71 patients with hepatic venous outflow obstruction between 1992 and 1997. Twenty-seven patients presented with acute disease, while 44 had chronic presentation. Abdominal pain, distension, jaundice and upper gastrointestinal bleeding were the commonest presenting symptoms. The majority of patients had distended veins, hepatomegaly, splenomegaly, ascites and ankle oedema. The diagnosis was made on the basis of inferior vena cavography/functional hepatography and pulsed Doppler ultrasonography and/or liver biopsy in 39 patients and pulsed Doppler ultrasonography and/or liver biopsy in 32 patients. Pulsed Doppler ultrasonography accurately detected the site of the block in 31 of 39 patients (79.4%). The obstruction was in the hepatic vein in 20 patients, in the inferior vena cava in 10, and in both in 41 patients. Aetiologically, four had pregnancy-related disease, four tumour-related, three hypercoagulable states, 18 inferior vena cava membranes and 42 were idiopathic. Of 30 patients in whom liver biopsy was carried out, eight had centrizonal congestion and necrosis, 13 had mixed features and nine had established cirrhosis. Seven patients underwent a shunt operation and surgical membranotomy was carried out in one. Three patients (4.2%) died in the hospital.

CONCLUSIONS

Hepatic venous outflow obstruction is a common problem; patients present with abdominal pain, distension, jaundice, distended veins, ascites and ankle oedema. Chronic presentation is more frequent. Pulsed Doppler ultrasound, venography and liver biopsy are very helpful in diagnosis.