Nanopore Technology: A Simple, Inexpensive, Futuristic Technology for DNA Sequencing.

In health care, importance of DNA sequencing has been fully established. Sanger's Capillary Electrophoresis DNA sequencing methodology is time consuming, cumbersome, hence become more expensive. Lately, because of its versatility DNA sequencing became house hold name, and therefore, there is an urgent need of simple, fast, inexpensive, DNA sequencing technology. In the beginning of this century efforts were made, and Nanopore DNA sequencing technology was developed; still it is infancy, nevertheless, it is the futuristic technology.

Micrometer-sized negative-ion accelerator based on ultrashort laser pulse interaction with transparent solids.

We report here energetic (>100 keV) negative hydrogen ions (H(-)) generated in the interaction of moderately intense (10(18) W cm(-2)) ultrashort laser pulses (45 fs) with transparent hydrogen containing solid targets. An unambiguous and consistent detection of negative hydrogen ions, with a flux of 8×10(11)H(-) ions/sr, has been observed in every single laser shot, using a Thomson parabola ion spectrograph. Simple estimates based on charge transfer cross sections match well with experimental observations. Our method offers the implementation of an intense, ultrashort laser based negative-ion source at a higher repetition rate, which can be important for various applications.

Role of target material in proton acceleration from thin foils irradiated by ultrashort laser pulses.

We report on the proton acceleration studies from thin metallic foils of varying atomic number (Z) and thicknesses, investigated using a 45 fs, 10 TW Ti:sapphire laser system. An optimum foil thickness was observed for efficient proton acceleration for our laser conditions, dictated by the laser ASE prepulse and hot electron propagation behavior inside the material. The hydrodynamic simulations for ASE prepulse support the experimental observation. The observed maximum proton energy at different thicknesses for a given element is in good agreement with the reported scaling laws. The results with foils of different atomic number Z suggest that a judicious choice of the foil material can enhance the proton acceleration efficiency, resulting into higher proton energy.

Effect of postural changes on normal and stenosed common carotid artery using FSI.

Gravity associated with postural changes has a strong bearing on haemodynamics of blood flow in arteries. Its effect on stenosed cases has not been widely investigated. In the present study, variation observed in blood flow during postural changes is investigated for different conditions like standing, sleeping and head-down position. A fluid structure interaction study is carried out for idealized normal and 75% eccentric and concentric stenosed common carotid normal artery. The results clearly indicate the effects of altered gravity on flow conditions. It was found to be very significant during head-down position and demonstrated very high arterial blood pressure in stenosed common carotid when compared with normal carotid.

A compact 10 kW, 476 MHz solid state radio frequency amplifier for pre-buncher cavity of free electron laser injector linear accelerator.

A 10 kW, 476 MHz, 0.1% duty cycle solid state RF amplifier system for driving sub-harmonic, pre-buncher cavity of IR-FEL injector LINAC, has been developed at RRCAT. The 10 kW power is achieved by combining output of eight 1400 W amplifier modules using 8-way planar corporate combiner. The solid state amplifier modules have been developed using 50 V RF LDMOS transistors which although meant for push-pull operation are being used in single ended configuration with matching circuit developed on a thin (25 mils), high dielectric constant (9.7), low loss microwave laminate with an aim to have a compact structure. Ease of fabrication, modularity, small size, and low cost are the important features of this design which could be used as a template for low duty cycle medium to high pulsed power UHF amplifier system.

Nanotechnology: A Revolution in Cancer Diagnosis.

Nanotechnology has brought revolution in cancer detection and treatment. It has capability to detect even a single cancerous cell in vivo and deliver the highly toxic drugs to the cancerous cells. Nanoshells, carbon nanotubes, quantum dots, supermagnetic nanoparticles, nano wires, nanodiamonds, dandrimers, and recently synthesized nanosponges are some of the materials used for cancer detection. Using specific cross linkers, such as specific antibodies against cancer cells individual cancer cells can be located. With the aid of a novel set of lipid-coated, targeted quantum dots a method for quantifying multiple specific biomarkers on the surfaces of individual cancer cells was also developed. This approach to quantitative biomarker detection stands to improve the histopathology methods used to diagnosis pancreatic and other cancers and enable the development of methods to spot cancer cells circulating in the blood stream. Certain nano materials can also deliver cancer drugs at the site so the drug toxicity can also be reduced.

A diagnostic system for electrical faults in a high current discharge plasma setup.

A diagnostic system to detect electrical faults inside a coaxial high current discharge device is presented here. This technique utilizes two biconical antennas picking up electromagnetic radiation from the discharge device, a voltage divider sensing input voltage, and a Rogowski coil measuring the main discharge current. A computer program then analyses frequency components in these signals and provides information as to whether the discharge event was normal or any breakdown fault occurred inside the coaxial device. The diagnostic system is developed for a 450 kV and 50 kA capillary discharge plasma setup. For the setup various possible faults are analyzed by electrical simulation, followed by experimental results. In the case of normal discharge through the capillary load the dominant frequency is ∼4 MHz. Under faulty conditions, the peak in magnitude versus frequency plot of the antenna signal changes according to the fault position which involves different paths causing variation in the equivalent circuit elements.

Study of self-generated magnetic fields in laser produced plasmas using a three-channel polaro-interferometer.

Self-generated magnetic fields produced in laser plasmas at moderate laser intensities have been measured using a three-channel polaro-interferometer. The main elements of this device are two birefringent calcite wedges placed between two crossed polarizers. Using this device, the spatial profiles of (a) the rotation angle (polarometry), (b) the electron density (interferometry), and (c) the transmitted probe beam intensity (shadowgraphy) are recorded simultaneously using a digital camera with a large format CCD in a single laser shot. Magnetic fields of 2-4 MG had been estimated in aluminum plasma at laser intensities ~10(13) W/cm(2). It is also possible to use this device in other configurations to get time resolved information.

Fast ion generation in the cathode plasma jet of a multipicosecond laser-triggered vacuum discharge.

Ion generation in the cathode plasma jet of a moderate-current (approximately 2.3 kA), low-energy (< or = 20 J) vacuum spark discharge triggered by approximately 27 ps, 10 mJ laser pulses is studied using time of flight technique. Fastest ion velocity and velocity corresponding to the peak of the time of flight signals for Al cathode were measured to be approximately 5.25x10(8) cm/s (energy of approximately 143 keV/u) and approximately 8.1x10(7) cm/s (energy of approximately 3.4 keV/u), respectively. Corresponding velocities in the case of ions generated from laser-produced Al plasma (energy of approximately 550 mJ, intensity of approximately 10(14) W/cm(2)) were found to be much smaller, viz., approximately 1.05x10(8) cm/s (energy of approximately 5.75 keV/u) and approximately 2.63x10(7) cm/s (energy of approximately 0.36 keV/u), respectively. Study shows efficient acceleration of ions in a current-carrying cathode plasma jet of a small-energy multipicosecond laser-triggered spark discharge as compared with that in a high-energy multipicosecond laser-produced plasma plume.

Formation of single pinched plasma point in the cathode plasma jet of a multipicosecond laser-triggered vacuum discharge.

Characteristics of cathode plasma jet pinching and x-ray emission from a multipicosecond laser-triggered vacuum discharge are presented. Discharge was created in between a planar Al cathode and a conical point-tip Ti anode (separation: 2-15 mm, circuit inductance of approximately 0.53 microH, peak discharge current of approximately 3 kA, and rise time of approximately 400 ns). For anode-cathode separation of approximately 13.5 mm, only a single pinched plasma point was formed in the cathode plasma jet at a distance of approximately 9.5 mm from the cathode. Quantitative analysis of the x-ray signals recorded using a pin diode with different filters and viewing different regions of the discharge, shows soft ( approximately keV photon energy) x-ray emission from the plasma point with a flux of approximately (3-5)x10(10) photons/sr, and multi-keV x-ray emission from the Ti anode with Kalpha ( approximately 4.51 keV) photon flux of approximately 10(10) photons/sr.

Significance of PAM histochemical reaction in delineating macrophages.

Periodic acid methenamine silver staining has been used for proof of the existence of carbohydrates in both paraffin and resin embedded tissues. The staining was applied to delineate macrophages that have been well known as cells of mononuclear phagocyte system by stainable nature for lysosomes, and it is found to be useful method for detection of macrophage. Fetal macrophage, which is often observed in placental villi, is called the highly vacuolated cell. Vacuoles in the cytoplasm seem to be empty with light microscopic staining, but it is clarified that they contain a full amount of carbohydrate. The present result leads us to the necessity of reconsidering the functional aspect of fetal macrophage.

Stereo-electron microscopy of the ovarian follicles of cat and mouse.

Three dimensional structure of developing ovarian follicles in the cat and the mouse were examined to clarify the cellular and the extra cellular components during follicular maturation by scanning electron microscopy. Epithelial cells of the membrana granulosa (MG) and the cumulus oophorus (CO) show variable morphology, which depends on the location of the cells in the follicle. In the small antral follicle, there is no morphological difference between the surface structure of the MG and the CO lining cells. In the large antral follicle, however, the lumenal lining cells of the MG change their spherical shape to a rather flattened one showing numerous pseudopodial processes creeping over the surrounding lumenal cells. The CO cells remain rounded with fine cytoplasmic protrusions on their outer surfaces which seem to make a network. The outer surface view of the zona appears as composed of labyrinthine canals with relatively large pores of various sizes, however, the inner surface is rather compact with a number of small pores.

Pulsed laser deposition of metal films and nanoparticles in vacuum using subnanosecond laser pulses.

A study of silver, chromium, stainless-steel, and indium thin films prepared by subnanosecond laser deposition in vacuum is reported. We compare the laser ablation in vacuum at the weak- and tight-focusing conditions of a Ti:sapphire laser beam and analyze the nanoparticles synthesized in the latter case using absorption spectroscopy, x-ray fluorescence, atomic force microscopy, and scanning electron microscopy. Our results show that the nanoparticle formation can be accomplished using long laser pulses under tight-focusing conditions.

Sex hormone receptors in the human eye.

Dissimilarities in ocular physiopathology exist between human males and females. These differences can be observed in the lacrimal and other eye-associated glands, the ocular surface, the crystalline lens, and the retinochoroid complexes. Literature on the subject revealed that because of sex steroid hormone (estrogen, progesterone, and androgen) actions, various physiological conditions, such as age, menstrual cycles, pregnancy, and menopause or andropause, where the hormone milieu changes, affect vision. Well-designed scientific studies are lacking on the subject, although such studies hold much potential value. This review analyzes the relatively new area of hormones and vision.

Protein nanotechnology - A powerful futuristic diagnostic technique.

Healthcare can be maintained well, when diagnosis is quick, accurate, cost-effective and painless. DNA and RNA based diagnosis may not reveal the right information for certain diseases. Identification and quantification of proteins and their folding mechanism are very important in diagnosis of diseases. Small quantities of proteins, which generally escape from detection and are responsible for the diseases, now can be quantified by protein nanotechniques which aids in the diagnosis. In this review, we have summarized the recent developments in nanotechnologies such as protein microarrays, biosensors etc. and their application in diagnosis of diseases at proteomics level have also been discussed.

Ultrasonography in Patients with Suspected Acute Appendicitis.

BACKGROUND: To evaluate the usefulness and limitations of graded compression ultrasonography in the diagnosis of clinically equivocal cases of suspected acute appendicitis at the setting of mid zonal military hospital of India. METHODS: A prospective study, graded compression ultrasonography with self localization was carried out with 3.5 MHz convex, 5 MHz convex and 7.5 MHz linear transducers (Wipro GE) in 69 clinically equivocal suspected cases of acute appendicitis. With maximal compression the anteroposterior diameter of appendix was measured from outer to outer wall. The main criterion for diagnosing appendicitis was demonstration of a non compressible appendix with anteroposterior dimension of 7mm or more. RESULT: Sonologically 36 (52%) cases were diagnosed as appendicitis. Anteroposterior outer diameter of inflamed appendices ranged from 7mm to 21mm (mean 10.5mm). 30 (83%) of 36 patients could accurately self localize the point of maximum tenderness. There were 01 false positive and 04 false negative cases. Sensitivity and specificity were 89.7% and 96.6% respectively. Positive and negative predictive values were 97.2% and 87.8% respectively. Alternative diagnoses were offered in 33 (47.8%) cases. Amongst these 33 cases, 14(42.4%) had abdominal pain of unknown origin. Gynaecologic, urologic and gastrointestinal aetiologies were established in 10(30.3%), 07(21.2%) and 02(6%) cases respectively. CONCLUSION: Graded compression ultrasonography superadded with self localization is an accurate means of diagnosing/excluding appendicitis in clinically equivocal cases of acute appendicitis and it is of great value in establishing alternative diagnoses.

Epidemiology based etiological study of pediatric cataract in western India.

BACKGROUND: Cataract is responsible for about 10% blindness among children in India. Etiology of cataract is not well defined especially for childhood cataracts and epidemiological data for Indian population is not available in details. AIM: This study was performed to survey the causes of childhood cataracts and to identify the preventable factors in four western states of India. SETTINGS AND DESIGN: The present study is a hospital-based, prospective study on 172 consecutive pediatric cataract patients. MATERIAL AND METHODS: Type of cataract was determined using slit-lamp bio-microscopy or operation microscope after mild general anesthesia especially on very young babies. Other anomalies of eye were determined using appropriate ophthalmic instruments. Parents of the patients were interviewed in their native language using a standardized questionnaire. Biochemical and microbiological tests such as for rubella, reducing sugar and blood glucose were also performed. RESULTS: Out of 172 children, 88.4% had non-traumatic cataract and 11.6% had traumatic cataracts. Among non-traumatic cataracts, 7.2% were hereditary, 4.6% were due to congenital rubella syndrome, 15.1% were secondary and 73.0% were undetermined. In the group of undetermined cases, during pregnancy 67% of the mother had history of illness, and 22% had taken medications during pregnancy. CONCLUSIONS: Our study shows that nearly 12% of non-traumatic cataract is due to potentially preventable causes. Health education of women to childbearing age and school children can decrease incidence of pediatric cataracts.

Nuclear localization of non-specific acid phosphatase(s) activity in rat vaginal epithelium.

The nuclear localization of non-specific acid phosphatase(s) in rat vaginal epithelial cells (VEC) by histochemical and biochemical techniques has been reported in the present work. By different histochemical methods, the enzyme activity was predominantly localized in certain nuclei but not in all of them, however, within the nucleus nucleoli are free from the enzyme activity. This enzyme is diffused in the nucleoplasm and perhaps tightly associated with the nuclear proteins. Very little activity was seen in the cytoplasm in the selective population of VEC. After 12 h treatment of estradiol 17beta in vivo the VEC lose the enzyme activity in the basal and intermediate layers, and the activity remains within the nuclei of luminal cells. Enzyme assay in low and high salt extracts of the isolated nuclei of the VEC with or without the enzyme inhibitors indicates that this enzyme may be present in isoforms in the VEC. No activity was observed in these cells at alkaline pH.