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To quantitatively test the hypothesis that older patients have increased thyroarytenoid muscle atrophy by comparing thyroarytenoid muscle volumes across different age groups.
A retrospective chart review was conducted. The study included 111 patients with no history of laryngeal pathology. Two investigators reviewed magnetic resonance imaging studies of these patients and manually traced the thyroarytenoid muscles on multiple slices bilaterally. Thyroarytenoid muscle volumes were then computed using imaging analysis software. Patients were stratified into three age groups (18–50 years, 51–64 years, and 65 years or older) for comparison.
Intra- and inter-rater reliabilities were excellent for all measurements (intraclass correlation co-efficient > 0.90). There was no statistically significant difference in the mean volumes of left and right thyroarytenoid muscles in all age and gender groups.
Given the lack of statistically significant difference in thyroarytenoid muscle volume between age groups on magnetic resonance imaging, the prevailing assumption that age-related thyroarytenoid muscle atrophy contributes to presbyphonia should be re-examined.
Soybean is a leading oilseed crop in India, which contains about 40% of protein and 20% of oil. Core collection will accelerate the management and utilization of soybean genetic resources in breeding programmes. In the present study, eight agromorphological traits of 3443 soybean germplasm were analysed for the development of core collection using the principal component score (PCS) strategy and the power core method. The PCS strategy yielded core collection (CC1) of 576 accessions, which accounted for 16.72% of the entire collection (EC). The analysis based on the power core programme resulted in CC2 of 402 accessions, which accounted for 11.67% of the EC. Statistical analysis showed similar trends for the mean and range estimated in both core collections and EC. In addition, the variance, standard deviation and coefficient of variance were in general higher in core collections than in the EC. The correlations observed in the EC in general were preserved in core collections. A total of 311 and 137 unique accessions were found in CC1 and CC2 in addition to 265 accessions that were found to be common in both core collections. These 265 common accessions were the most diverse core sets, which accounted for 7.64% of the EC. We proposed to constitute an integrated core collection (ICC) by integrating both common and unique accessions. The ICC comprised 713 accessions, which accounted for about 20.62% of the EC. Statistical analysis indicated that the ICC captured maximum variation than CC1 and CC2. Therefore, the ICC can be extensively evaluated for a large number of economically important traits for the identification of desirable genotypes and for the development of mini core collection in soybean.
For over three decades, bone conduction hearing aids have been changing the lives of patients with impaired hearing. The size, appearance and fitting discomfort of early generations of bone conduction hearing aids made them unpopular. The advent of bone-anchored hearing aids in the 1970s offered patients improved sound quality and fitting comfort, due to the application of osseointegration. However, the issue of post-operative peri-abutment pin tract wound infection persisted. The Bonebridge system incorporates the first active bone conduction device, and aims to resolve peri-abutment issues. Implantation of this system in an Asian patient is presented.
A total of 675 stdrains of Salmonella bareilly received from different parts of India and France during 1959–92 were phage typed using six bacteriophages. Overall ttypability achieved was 90·8% with 23 distinctphage types excluding a group of untypable strains. Phage types have been defined in octal code. Simpson's coefficient was applied for diversity index having a value of 0·839. This system was found to be reproducible, stable and epidemiologically useful.
A novel direct cell printing technique has been developed to control and manipulate the position of cells on solid surfaces. The method utilizes microfabricated polymeric “quill-pen” cantilevers to transfer living cells onto a wide variety of surfaces. In contrast with existing cell deposition methods, such as ink jet or laser ablation methods, the quill-pen approach imparts minimal thermal and shear stress to cells, preserving cell viability and biological functionality. Deposition of both bacterial and mammalian cells into defined patterns has been demonstrated using this method. The size of printed, cell-containing droplets could be controlled by varying the geometry of the quill-pen stylus and by varying printing conditions such as contact time, relative humidity, and surface hydrophobicity. Initial experiments using 10 μm diameter polymer beads demonstrated that the number of beads per droplet could be controlled by varying spot size and particle concentration in the printing solution. Spots could be printed ranging from 20 μm and 100 μm in diameter with approximate volumes ranging from 1-250 pL. We demonstrated deposition of both cells and beads onto a variety of solid surfaces including agarose gel, polystyrene, polyethylene, and glass. Printed cells have also been immobilized on glass and polymer surfaces using biocompatible hydrogel materials (both alginic acid and hyaluronic acid-based matrices) as well as poly-L-lysine. Similar to polymer beads, the number of cells in printed droplets was shown to be dependent upon the size of the droplet, and could be varied by adjusting the concentration of cells present in the printing fluid. As few as one cell per spot could be achieved by adjusting these parameters. The viability and proliferation of printed cells has been evaluated using live optical imaging to observe cell growth and division. Both bacterial cells (Escherichia coli) and mammalian cells were able to divide and proliferate for at least 96 hr post-printing (experiments were discontinued after 96 hr). Live/dead staining was also used to confirm the viability of printed cells. Rat mammary adenocarcinoma MTLn3 cells and mouse embryonic stem cells were also shown to survive the printing process for at least 24 - 96 hr post-printing. These results demonstrate the feasibility of the printing method and its compatibility with a wide range of cell types. It is especially noteworthy that embryonic stem cells could survive the printing process (and proliferate on the printing substrate). This novel printing method has applications for tissue engineering, cell-to-cell signaling studies, and for directly interfacing cells with nanodevices and biosensors.
The deformation of polycrystalline uranium 6 wt. % niobium (U6Nb) was studied in-situ during uniaxial tensile and compressive deformation by time-of-flight neutron diffraction. Diffraction patterns were recorded at incremental strains to roughly 4% total deformation. The asymmetry in the crystallographic response of the lattice is discussed.
We report rheological data on hydrogels formed from triblock copolymers of poly(L-lactide) (PLLA) and poly(ethylene oxide) (PEO). We are able to create gels with elastic moduli greater than 10,000 Pa, which is an order of magnitude higher than previously achieved with related physically associated gels of similar chemistry. Moreover, the value of the elastic modulus strongly depends on PLLA block length, offering a mechanism to control the mechanical properties as desired for particular applications. Additionally, we have developed protocols for using these materials for cell encapsulation and present preliminary cell viability studies for encapsulated human liver cells (HepG2 cell line). Our results have implications for the design of new materials for soft tissue engineering, where native tissues have moduli in the kPa range.
Mandibular osteochondromas, although rare, predominantly involve the condyloid and coronoid processes. An extremely rare case arising from the inner aspect of the gonion is reported here. Only one such case has been reported in the literature so far. Despite being very slow growing and having a benign course, histopathological examination showed reactive changes that may be confused with sarcomatous transformation. We advocate surgical excision using a combined external and internal approach followed by regular post-operative review. The relevant literature has been reviewed but various surgical approaches as advocated in the past have not been found suitable.
Most outbreaks of viral hepatitis in India are caused by hepatitis E. This report describes an
outbreak of hepatitis B in a rural population in Haryana state in 1997. At least 54 cases of
jaundice occurred in Dhottar village (population 3096) during a period of 8 months; 18
(33·3%) of them died. Virtually all fatal cases were adults and tested positive for HBsAg (other
markers not done). About 88% (21/24) of surviving cases had acute or persistent HBV/HCV
infections; 54% (13/24) had acute hepatitis B. Many other villages reported sporadic cases and
deaths. Data were pooled from these villages for analysis of risk factors. Acute hepatitis B
cases had received injections before illness more frequently (11/19) than those found negative
for acute or persistent HBV/HCV infections (3/17) (P = 0·01). Although a few cases had other
risk factors, these were equally prevalent in two groups. The results linked the outbreak to the
use of unnecessary therapeutic injections.
In Rajahmundry town in India, 234 community cases of jaundice were interviewed for risk
factors of viral hepatitis B and tested for markers of hepatitis A–E. About 41% and 1·7% of
them were positive for anti-HBc and anti-HCV respectively. Of 83 cases who were tested
within 3 months of onset of jaundice, 5 (6%), 11 (13·3%), 1 (1·2%), 5 (6%) and 16 (19·3%)
were found to have acute viral hepatitis A–E, respectively. The aetiology of the remaining 60%
(50/83) of cases of jaundice could not be established. Thirty-one percent (26/83) were already
positive for anti-HBc before they developed jaundice. History of therapeutic injections before
the onset of jaundice was significantly higher in cases of hepatitis B (P = 0·01) or B–D
(P = 0·04) than in cases of hepatitis A and E together. Other potential risk factors of hepatitis
B transmission were equally prevalent in two groups. Subsequent studies showed that the
majority of injections given were unnecessary (74%, 95% CI 66–82%) and were administered
by both qualified and unqualified doctors.
We describe our strategies and results in the preparation of supramolecularly ordered ultrathin films of DNA assemblies using the layer-by-layer (LbL) alternate polyelectrolyte adsorption technique. The properties of DNA are intimately associated with their polyelectrolyte behavior in solution. Deposition at interfaces is governed by conformation, orientation, and charge density of these biomolecules in relation to the physisorption phenomena in oppositely charged surfaces. Thus, controlling the nature of surfaces (polymer charge density, ionic strength, other non-covalent interactions, etc.) is important in modifying the adsorption phenomena. In this work, differences in adsorption and incorporation of DNA with dyes, linear polymers and dendrimers are highlighted. A number of surface sensitive spectroscopic and microscopic techniques were used to probe the adsorption and multilayer assembly phenomena, e.g. surface plasmon resonance spectroscopy (SPS), AFM, quartz crystal microbalance (QCM) and ellipsometry. These studies are important for future applications such as the use of polycations as non-viral gene transfection vectors for drug-delivery and DNA adsorption on microarray surfaces. By combining with the alternate assembly of azobenzene and phthalocyanine dyes, we have been able to prepare optobiolelectronic substrates where the phenomena of irradiation and electrochemistry can be used to probe the ordering and response of these films.
We have developed a novel electrochemical system for field assisted, fluidic assembly of objects on a microfabricated silicon substrate by means of electrical addressing. The principle of our technique is based on the movement of charged species in solution to oppositely charged electrodes, as seen commonly in electrophoresis. Here, charged species such as beads and cells are moved electrokinetically through an aqueous solution towards a charged electrode. Micro patterning of the electrodes allows localization of charged species. We present a theoretical framework to predict the electric potential for assembly and disassembly of spherical objects. We correlate theoretical predictions with the motion of negatively charged polystyrene beads of 20 μm diameter on 100 μm feature micro patterned substrates. In addition, we extended these results to arraying of 20-30 μm diameter live mammalian cells by means of electrical addressing. This technique has applications in creation of ‘active’ cellular arrays for cell biology research, drug discovery and tissue engineering.
Tribochemical studies of the effect of lubricant bonding on the tribology of the head/disk interface (HDI) were conducted using hydrogenated (CHx) carbon disk samples coated with perfluoropolyether ZDOL lubricant. The studies involved drag tests with uncoated and carboncoated Al2O3-TiC sliders and also thermal desorption experiments in an ultra-high vacuum (UHV) tribochamber. We observed that a larger mobile lubricant portion significantly enhances the wear durability of the (head/disk interface) HDI by providing a reservoir to constantly replenish the lubricant displaced in the wear track during drag tests. In the thermal desorption tests we observed two distinct temperatures of desorption. The mobile ZDOL layer is desorbed at the lower thermal desorption temperature and the residual bonded ZDOL layer is desorbed at the higher thermal desorption temperature. We also observed that the hydrogen evolution from CHx overcoats initiates lubricant catalytic decomposition with uncoated Al2O3/TiC sliders, forming CF3 (69) and C2F5 (119). The generation of Hydroflouric acid (HF) during thermal desorption experiments provides the formation mechanism of Lewis acid, which is the necessary component for catalytic reaction causing Z-DOL lube degradation.
Carbon films exhibiting a peak hardness of 59 GPa have been produced using pulsebiased cathodic-arc deposition. This value is much greater than that expected of an amorphous "diamond-like" carbon (die) film and is well within the hardness range of chemically vapor-deposited diamond. Furthermore, this peak hardness is observed at an indentation depth of approximately 50 nm and not on the upper surface of the film. A structural analysis by transmission electron microscopy (TEM) has been conducted in order to explain these mechanical phenomena.
Details of the sputtering apparatus are described elsewhere. Films for this study were deposited on silicon using a two-step process in which a thin layer, approximately 10 nm, was first deposited at a relatively high substrate bias (~2 kV) followed by growth of the majority of the film at a lower bias (~200 V). Plan-view examination of carbon films revealed both uniformly amorphous regions and extensive nanocrystalline phase regions.
Nanoindentation and nanoscratching experiments have been performed to assess the mechanical properties of several carbon thin films with potential application as wear resistant coatings for magnetic disks. These include three hydrogenated-carbon films prepared by sputter deposition in a H2/Ar gas mixture (hydrogen contents of 20, 34, and 40 atomic %) and a pure carbon film prepared by cathodic-arc plasma techniques. Each film was deposited on a silicon substrate to thickness of about 300 nm. The hardness and elastic modulus were measured using nanoindentation methods, and ultra-low load scratch tests were used to assess the scratch resistance of the films and measure friction coefficients. The results show that the hardness, elastic modulus, and scratch resistance of the 20% and 34% hydrogenated films are significantly greater than the 40% film, thereby showing that there is a limit to the amount of hydrogen producing beneficial effects. The cathodic-arc film, with a hardness of greater than 59 GPa, is considerably harder than any of the hydrogenated films and has a superior scratch resistance.
Nanoindentation and nanoscratching experiments have been performed to assess the mechanical and tribological behavior of three thin film materials with potential application as wear resistant coatings for magnetic disk storage: (1) hydrogenated-carbon (CHx); (2) nitrogenated-carbon (CNx); and (3) boron suboxide (BOx). The hardness and elastic modulus were measured using nanoindentation. Ultra-low load nanoscratching tests were performed to assess the relative scratch resistance of the films and measure their friction coefficients. The mechanical and tribological performance of the three materials are discussed and compared.
In a prospective study of 144 consecutive male patients with psychosexual disorders, comprising 93 with Dhat syndrome with or without impotence or premature ejaculation, 21 with premature ejaculation, and 30 suffering only impotence, the commonest associated psychiatric illness was neurotic depression (39%) followed by anxiety neurosis (21 %), while 31% did not receive a psychiatric diagnosis. The common presenting symptoms of Dhat syndrome were weakness (71 %), fatigue (69%), palpitations (69%), and sleeplessness (62%). After random allocation into groups, four types of treatment were given: an anti-anxiety drug, an antidepressant, a placebo, or counselling. The best response was seen with the anti-anxiety and antidepressant drugs. Twenty-one patients dropped out of treatment; 15 of whom were from the counselling group.