Laser excited long lasting luminescence in CaAl₂O₄: Eu³⁺/Eu²⁺+Nd³⁺ phosphor

The europium and neodymium oxides doped nano-structured calcium aluminate phosphor samples have prepared through combustion technique and their luminescence properties are studied using laser excitations. Samples prepared in open atmosphere showed the presence of both Eu(3+) and Eu(2+) states and their ratio changes with calcination temperature. Single Eu(3+)/Eu(2+) ions doped sample has found to give broad emission at 450 nm without the persistence glow while the Eu(3+)+Nd(3+) ions codoped sample has shown persistence glow at 450 nm (Eu(2+)) on 355 nm laser excitation. Wavelength selective excitations show that 266 nm excitation gives the intense emissions from both Eu(3+) and Eu(2+) states with no afterglow but 355 nm excitation gives negligible emission from Eu(3+) ions and a strong afterglow at 450 nm wavelength. The mechanism of wavelength dependent phosphorescence has been discussed. Studies on Stark splittings and their relative intensities in emission spectra of Eu(3+) ions have shown that Eu(3+) ion can be used as excellent probe of crystal structure.

Proniosomal formulation of curcumin having anti-inflammatory and anti-arthritic activity in different experimental animal models

Curcumin, the active ingredient of the spice turmeric, has a long history as an herbal remedy for a variety of diseases. Transdermal drug delivery has been recognized as an alternative route to oral delivery. Proniosomes offer a versatile vesicle delivery concept with the potential for drug delivery via the transdermal route. In this study, different proniosomal gel bases were prepared by the ether injection method, using Span 60 and Span 80, Tween 20, cholesterol, and formulation PA2. They were characterized by scanning electron microscopy, revealing vesicular structures, and assessed for stability and effect on in vitro skin permeation using rat skin. Anti-inflammatory and anti-arthritic effects of formulation PA2 and PB1 were compared with a standard market product containing indomethacin. The effect of formulation PA2 and PB1 was evaluated for acute inflammation in carrageenan induced rat paw edema and for chronic inflammation in complete Freud's adjuvant (CFA) induced arthritis in rats. Further histopathological and radiographic evaluation was performed. The investigated curcumin loaded proniosomal formula proved to be non-irritant, non-toxic, but had lower anti-inflammatory and anti-arthritic effects than the marketed indomethacin products.

Unilateral lower motor neuron-type of facial palsy following snake bite presumably due to Krait (Bungarus Caeruleus)

We describe an unusual case of snake bite presumably due to Krait (Bungarus Caeruleus) in a 12-year-old child from Mohali, Punjab. He presented with a history of bite behind his left ear, while he was sleeping at night on floor. He had bilateral ptosis, dysphonia initially, which progressed gradually to cause respiratory paralysis. Child was managed with antisnake venom, ventilation and other supportive measures. He recovered gradually, but persisted to have lower motor neuron paralysis of left facial nerve, which was noted post extubation. This uncommon presentation could be because of exposure of the facial muscles to the venom, spreading directly from the injection site and destroying the nerve terminals of facial nerve in the muscle tissue. At three months follow-up, child showed complete recovery. Facial nerve involvement following snake bite, which usually has a good prognosis, remain an uncommon presentation in paediatric age group. J Nepal Paediatr Soc 2012;32(2):184-186 doi: http://dx.doi.org/10.3126/jnps.v32i2.5824

Molecular profiling of rhizosphere bacterial communities associated with Prosopis juliflora and Parthenium hysterophorus

Prosopis juliflora and Parthenium hysterophorus are the two arid, exotic weeds of India that are characterized by distinct, profuse growth even in nutritionally poor soils and environmentally stressed conditions. Owing to the exceptional growth nature of these two plants, they are believed to harbor some novel bacterial communities with wide adaptability in their rhizosphere. Hence, in the present study, the bacterial communities associated with the rhizosphere of Prosopis and Parthenium were characterized by clonal 16S rRNA gene sequence analysis. The culturable microbial counts in the rhizosphere of these two plants were higher than bulk soils, possibly influenced by the root exudates of these two plants. The phylogenetic analysis of V1_V2 domains of the 16S rRNA gene indicated a wider range of bacterial communities present in the rhizosphere of these two plants than in bulk soils and the predominant genera included Acidobacteria, Gammaproteobacteria, and Bacteriodetes in the rhizosphere of Prosopis, and Acidobacteria, Betaproteobacteria, and Nitrospirae in the Parthenium rhizosphere. The diversity of bacterial communities was more pronounced in the Parthenium rhizosphere than in the Prosopis rhizosphere. This culture-independent bacterial analysis offered extensive possibilities of unraveling novel microbes in the rhizospheres of Prosopis and Parthenium with genes for diverse functions, which could be exploited for nutrient transformation and stress tolerance in cultivated crops.

Reviewing host proteins of Rhabdoviridae: possible leads for lesser studied viruses

Rhabdoviridae, characterized by bullet-shaped viruses, is known for its diverse host range, which includes plants, arthropods, fishes and humans. Understanding the viral-host interactions of this family can prove beneficial in developing effective therapeutic strategies. The host proteins interacting with animal rhabdoviruses have been reviewed in this report. Several important host proteins commonly interacting with animal rhabdoviruses are being reported, some of which, interestingly, have molecular features, which can serve as potential antiviral targets. This review not only provides the generalized importance of the functions of animal rhabdovirus-associated host proteins for the first time but also compares them among the two most studied viruses, i.e. Rabies virus (RV) and Vesicular Stomatitis virus (VSV). The comparative data can be used for studying emerging viruses such as Chandipura virus (CHPV) and the lesser studied viruses such as Piry virus (PIRYV) and Isfahan virus (ISFV) of the Rhabdoviridae family.

Light-into-heat conversion in La2O3:Er(3+)-Yb3+ phosphor: an incandescent emission

Low-power-threshold cw laser-induced incandescence (CWLII) has been observed in La(2)O(3):Er(3+)-Yb(3+) phosphor on excitation by a 976 nm IR laser. It is suggested that incandescence originates from the extensive heating induced by the nonradiative processes taking place following the laser excitation. Other mechanisms for similar observations have also been suggested in the literature and have been discussed with the present observations. The estimated temperature for the CWLII approaches around 2650 K, and this seems to provide an effective way to rapidly attain high temperature in nano/microvolumes of phosphor. The phosphor exhibited efficient upconversion, and the ratio of the (2)H(11/2)→(4)I(15/2) and (4)S(3/2)→(4)I(15/2) band intensities of Er(3+) permits measurement of the temperature rise, from a distance.

Pressure necrosis secondary to negative pressure dressing

Wound complications in patients with significant co-morbidities is common; however, in our patient the problem was compounded by the inappropriate placement of negative pressure dressing.

A magnetically driven piston pump for ultra-clean applications

A magnetically driven piston pump for xenon gas recirculation is presented. The pump is designed to satisfy extreme purity and containment requirements, as is appropriate for the recirculation of isotopically enriched xenon through the purification system and large liquid xenon time projection chamber of EXO-200. The pump, using sprung polymer gaskets, is capable of pumping more than 16 standard liters per minute of xenon gas with 750 Torr differential pressure.

Hearts from DCD donors display acceptable biventricular function after heart transplantation in pigs

Cardiac transplantation is in decline, in contrast to other solid organs where the number of solid organ transplants from donors after circulatory death (DCD) is increasing. Hearts from DCD donors are not currently utilized due to concerns that they may suffer irreversible cardiac injury with resultant poor graft function. Using a large animal model, we tested the hypothesis that hearts from DCD donors would be suitable for transplantation. Donor pigs were subjected to hypoxic cardiac arrest (DCD) followed by 15 min of warm ischemia and resuscitation on cardiopulmonary bypass, or brainstem death (BSD) via intracerebral balloon inflation. Cardiac function was assessed through load-independent measures and magnetic resonance imaging and spectroscopy. After resuscitation, DCD hearts had near normal contractility, although stroke volume was reduced, comparable to BSD hearts. DCD hearts had a significant decline in phosphocreatine and increase in inorganic phosphate during the hypoxic period, with a return to baseline levels after reperfusion. After transplantation, cardiac function was comparable between BSD and DCD groups. Therefore, in a large animal model, the DCD heart maintains viability and recovers function similar to that of the BSD heart and may be suitable for clinical transplantation. Further study is warranted on optimal reperfusion strategies.

Cytogenetic, Y chromosome microdeletion, sperm chromatin and oxidative stress analysis in male partners of couples experiencing recurrent spontaneous abortions

PURPOSE

Etiology in majority of couples experiencing recurrent spontaneous abortions (RSA) is still unknown. The aim of the study was to find the role of cytogenetic abnormalities, Y chromosome microdeletion, oxidative stress (OS) and sperm DNA fragmentation in male partners of couples experiencing RSA.

METHODS

Forty-eight couples with history of RSA and 20 fertile controls were included in the study. The study subjects were divided into male partners of RSA couples with abnormal sperm parameters (SA) (N = 16), male partners of RSA couples with normal sperm parameters (NS) (N = 32) and age-matched fertile controls with normal sperm parameters (FC) (N = 20).

RESULTS

One of 48 men (2%) showed 46, XY (1qh-) chromosomal complement. None of the cases including FC showed deletion in any of the 3 AZF loci on Y chromosome long arm. Sperm count was found be significantly lower in SA cases as compared to group NS cases (P < 0.0001) and FC (P < 0.005). Sperm forward motility was found to be significantly (P < 0.05) lower in SA cases as compared to NS and FC. Male partners of RSA couples with abnormal sperm parameters had higher reactive oxygen species (ROS) levels (P < 0.005) and sperm DNA damage (P < 0.0001), however, in male partners of RSA couples with normal sperm parameters had only increased (P < 0.0001) sperm DNA damage.

CONCLUSION

Other than chromosomal anomalies, sperm DNA fragmentation and seminal OS may be the underlying pathology in RSA, thus screening for seminal ROS levels and DNA fragmentation has diagnostic and prognostic capabilities.

Umbilical metastasis: a case series of four Sister Joseph nodules from four different visceral malignancies

Sister Joseph nodule is a metastatic umbilical lesion secondary to a primary malignancy of any viscera. It can be a presenting symptom (a sign of undiagnosed malignancy) or a symptom or sign of progression or recurrence in a known case. Its incidence is 1%-3% of all intra-abdominal or pelvic malignancies. Here, we present 4 such cases, with Sister Joseph nodule as a finding ofpresentation in a case of gallbladder carcinoma,progression in a case of malignant gastrointestinal stromal tumour,recurrence in a case of ovarian carcinoma, andpresentation in a case of rectal carcinoma.The clinicopathologic features of all 4 patients are discussed, and the related literature is briefly reviewed.

Effect of ZnX (X=F2 and Cl2) as modifier on luminescence properties of Ho3+/Yb3+ doped tellurite glasses

Optical absorption and photoluminescent properties of Ho(3+)/Yb(3+) co-doped tellurite and zinc halide tellurite glasses are investigated. The effect of zinc halides as modifier on the luminescence properties of above mentioned samples has been explored. Two intense upconversion emission bands centered at 546 ((5)F(4), (5)S(2)→(5)I(8)) and 660 ((5)F(5)→(5)I(8)) nm are observed when samples are excited by 976 nm radiation. Zinc halides act as quencher when 976 nm excitation source is used. The up and downconversion emission spectra are recorded with 532 nm excitation source also. In this case also, zinc halides do not show any improvement. The dependence of upconversion intensities on excitation power and temperature is discussed. The power dependence study shows a quadratic dependence of fluorescence intensity on the excitation power while decrement in emission intensity of different transitions at different rates is observed in temperature dependence study. The possible upconversion mechanisms are also discussed in order to understand the energy transfer between Yb(3+) and Ho(3+) ions.

Optimization of selective emitter fabrication method for solar cells using a laser grooving

In this paper, screen-printing laser grooved buried contact (LGBC) method was applied, which is compatible with the existing screen-printed solar cell equipment and facilities. Experiments were performed in order to optimize short circuit current (I(sc)), open circuit voltage (V(oc)) and fill factor of high efficiency solar cells. To enhance I(sc), V(oc) and efficiency, heavy doping was performed at low sheet resistance in the laser grooved region of the cell. In contrast, light doping was carried out at a high sheet resistance in the non-laser grooved region. To increase fill factor, porous silicon found on the wafer after dipping in an HF solution to remove SiN(x), was cleared. The fabricated screen-printing LGBC solar cell using a 125 mm x 125 mm single crystalline silicon wafer exhibited an efficiency of 17.2%. The results show that screen-printing LGBC method can be applied for high efficiency solar cells.

'It's like taking poison to kill poison but I have to get better': a qualitative study of beliefs about medicines in Rheumatoid arthritis and Systemic lupus erythematosus patients of South Asian origin

OBJECTIVE

To investigate factors that influence beliefs about medicines in patients of South Asian origin with rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

METHODS

Qualitative methodology was used to explore the health beliefs of South Asian patients and in particular the factors that influenced their beliefs about medicines and disease modifying anti-rheumatic drugs (DMARDs). Thirty two patients with RA and SLE took part in focus group discussions. Patients who chose to participate in focus groups conducted in English were compared with those who chose to participate groups conducted in Punjabi or Urdu.

RESULTS

Three main themes emerged to explain patients beliefs about medicines: (1) Beliefs about the necessity of DMARDs; (2) Concerns about DMARDs and other prescribed medicines including: (a) long-term side-effects; (b) the apparent lack of efficacy of some therapies; (c) concerns about changing from one drug to another and the large numbers of different medicines being taken; (3) Contextual factors which informed the patient's view on the necessity for particular medicines and concerns about them including: (a) beliefs about the causes of disease and the influence of religious beliefs on this; (b) barriers to communication with health care professionals about the medications being prescribed in clinic. In addition, our data revealed that these beliefs about DMARDs had important consequences for patient behaviour, including the use of traditional dietary and other non-pharmacological approaches. There were differences in views expressed between those who chose to speak in English and those who did not.

CONCLUSION

This study has identified themes that explain previous findings of negative beliefs about medicines in patients of South Asian origin. Beliefs about the causes of disease had an important impact on the way some patients viewed medicines for RA and SLE. This will have implications for educational programmes designed to promote patient involvement in disease management.

Adhesion Energy Measurements of Multilayer Low-K Dielectric Materials for ULSI Applications

Currently, the IC industry is researching the integration of a variety of materials to meet the low dielectric constant requirement for improved back-end of line (BEOL) interconnect performance. One critical dimension for successful ntegration of these new materials is maintaining mechanical integrity through multilayer processes. This includes both cohesive and adhesive fracture resistance. The latter adds additional complexity in that adhesive toughness is a function of the adherend materials and the processes used to join them. Hence, many good dielectric materials may be rematurely eliminated from further research not because of inherently poor adhesion but because of the necessity to optimize processing strategies.

In this paper, we use the modified Edge Liftoff Test (m-ELT) to quantify the mechanical adhesion of multilayer blanket coatings. A specific example is used to demonstrate the utility of combining the m-ELT with surface analysis to optimize the reliability of low-K dielectric resins for use in ULSI applications. The system studied consists of a Cyclotene™ 5021(BCB) low-K material integrated with CVD aluminum for single level, damascene structures. The effects of liner layer metallurgy and surface plasma treatments are measured. Surface analysis is done on the failed parts to understand the location of the failure. In this way recommendations for process optimization can be made.

Integration of PECVD Tungsten Nitride as a Barrier Layer for Copper Metallization

Amorphous tungsten nitride (WNx) is a promising diffusion barrier for extending Cu metallization beyond 0.18 μm. This study evaluates the barrier performance, adhesion, and step coverage of PECVD WN 0.5 integrated with a CVD Cu seed layer. The WN0.5 films exhibit amorphous structure with 33% bottom and side-wall step coverage in 0.14 μm wide structures with 9:1 aspect ratio. The potential of 50 Å WN0.5 as an effective Cu barrier is shown by the absence of Secco etch-pits in the Si substrate after a 30 min anneal at 500°C. When deposited on PECVD WN0.5 the CVD Cu films exhibit uniform nucleation, and as deposited resistivity of 2.5 μΩ-cm. Step coverage of the CVD Cu is better than 95% in 0.14 μm structures. Adhesion exceeding epoxy strength of the CVD Cu seed layer even to air-exposed WN0.5 is demonstrated using stud-pull adhesion tests.

Genetic and epigenetic factors: Role in male infertility

Genetic factors contribute upto 15%-30% cases of male infertility. Formation of spermatozoa occurs in a sequential manner with mitotic, meiotic, and postmeiotic differentiation phases each of which is controlled by an intricate genetic program. Genes control a variety of physiologic processes, such as hypothalamus-pituitary-gonadal axis, germ cell development, and differentiation. In the era of assisted reproduction technology, it is important to understand the genetic basis of infertility to provide maximum adapted therapeutics and counseling to the couple.

A simple radionuclide-driven single-ion source

We describe a source capable of producing single barium ions through nuclear recoils in radioactive decay. The source is fabricated by electroplating (148)Gd onto a silicon α-particle detector and vapor depositing a layer of BaF(2) over it. (144)Sm recoils from the alpha decay of (148)Gd are used to dislodge Ba(+) ions from the BaF(2) layer and emit them in the surrounding environment. The simultaneous detection of an α particle in the substrate detector allows for tagging of the nuclear decay and of the Ba(+) emission. The source is simple, durable, and can be manipulated and used in different environments. We discuss the fabrication process, which can be easily adapted to emit most other chemical species, and the performance of the source.

Upper airway detection and visualization from cone beam image slices

This paper describes a method developed to assist in the detection and reconstruction of a three dimensional (3D) model of the human upper airway using cone beam computed tomography (CBCT) image slices and a 3D Gaussian smoothing kernel. The segmented and reconstructed volumetric airway is characterized by the corresponding three principal axes that are selected for viewing direction orientation via rotation and translation. These axes are derived using the 3D Principal Component Analysis (PCA) result of the rendered volume. To finely adjust the view and access airway, the major and minor axes of each slice are also computed using the two dimensional (2D) PCA in the respective planes. The exterior volume view is visualized in two modes, namely, a solid surface (volume details transparent to user) view and a nontransparent (volume detail accessible) view. This functionality provides an application driven use of the 3D airway in CBCT based anatomy studies. The extracted information may be useful as an imaging biomarker in the diagnostic assessment of patients with upper airway respiratory conditions such as obstructive sleep apnea, allergic rhinitis, and other related diseases; as well as planning orthopedic/orthodontic therapies.

UV/blue upconversion in Nd3+:TeO2 glass, effect of modifiers and heat treatment on the fluorescence bands

Upconversion (UC) emissions in UV/blue region have been observed in Nd(3+) doped tellurite glass on 532 nm excitation. The UC bands have been observed at 360, 387, 417 and 452 nm due to the (4)D(3/2)-->(4)I(9/2), (4)D(3/2)-->(4)I(11/2), (4)D(3/2)-->(4)I(13/2) and (4)D(3/2)-->(4)I(15/2) transitions, respectively and they show two photon character. The effect of BaCO(3), BaF(2) and BaCl(2) glass modifiers on the UC efficiency has been studied and Judd-Ofelt intensity parameters have been calculated and compared. The BaCl(2) modified glass showed maximum UC intensity among the three modifiers and this enhancement in UC intensity has been related to the reduction in average phonon frequency of the glass sample. Heat treatments of the BaF(2) and BaCl(2) modified samples also show enhancement in UC intensity while the BaCO(3) modified sample has no such effect. Lifetime of the (4)D(3/2) level has been measured to understand the mechanism responsible for UC emission. Temperature dependent fluorescence studies have been done on the (4)F(3/2), (4)F(5/2) and (2)S(3/2) emitting levels and results show that Nd(3+) doped tellurite glass can be used as a temperature sensor.