Novel pericardial access device: design features and in vitro evaluation

We have designed, built and tested a novel needle for percutaneously accessing the pericardial space. The problem with accessing pericardial space is that the pericardium is against the heart. Our novel device incorporates a single spiral tine at the distal tip of a10-gauge needle, which engages the parietal pericardium tangentially to the surface of the heart. One can then pull the pericardium away, thus minimizing the risk of ventricular perforation associated with oblique axial approaches. Using linear low-density polyethylene film as a surrogate pericardium, we have demonstrated reliable pericardial engagement with successful first-time engagement rates of up to 72% (n = 25 attempts) at approach angles ranging from 0° (normal incidence) to 30°. The associated torques were approximately 1 N mm. The performance limits of the model and the implications for clinical use of such a device are discussed.

Diversity and screening for antimicrobial activity of endophytic fungi from Alstonia scholaris

Endophytic fungi of three tissues (petiole, bark and leaf) of Alstonia scholaris were assessed. A total number of 1,152 endophytic fungi were isolated from 1,002 different plant segments of seven different localities of Paschim Medinipur, West Bengal, India. The isolated fungi belong to nineteen genera, including four unidentified fungi and yeast. Colletotrichum sp. (20.39%) and Sordaria sp. (29.68%) were most commonly isolated from this plant. Hyalopus sp., Fusarium sp. and Curvularia sp. were also isolated. The colonization frequency of endophytic fungi is much higher in leaves (44.66%) in comparison to petioles (32.16%) and barks (23.17%). The study provided evidence for tissue specificity of endophytic fungi. The endophytic fungal species diversity was higher in plant segments collected from Gopegarh and Khoirullahchak, while diversity was the lowest in Rice mill area. Screenings of antimicrobial activity of these isolated endophytic fungi were done. Eight endophytic fungi showed antimicrobial activity. Among them Curvularia sp., Aspergillus sp. and one unidentified fungus showed maximum activity against test pathogens.

Spectroscopy of few-electron single-crystal silicon quantum dots

A defining feature of modern CMOS devices and almost all quantum semiconductor devices is the use of many different materials. For example, although electrical conduction often occurs in single-crystal semiconductors, gates are frequently made of metals and dielectrics are commonly amorphous. Such devices have demonstrated remarkable improvements in performance over recent decades, but the heterogeneous nature of these devices can lead to defects at the interfaces between the different materials, which is a disadvantage for applications in spintronics and quantum information processing. Here we report the fabrication of a few-electron quantum dot in single-crystal silicon that does not contain any heterogeneous interfaces. The quantum dot is defined by atomically abrupt changes in the density of phosphorus dopant atoms, and the resulting confinement produces novel effects associated with energy splitting between the conduction band valleys. These single-crystal devices offer the opportunity to study how very sharp, atomic-scale confinement--which will become increasingly important for both classical and quantum devices--influences the operation and performance of devices.

First principles quantum dynamical investigation provides evidence for the role of polycyclic aromatic hydrocarbon radical cations in interstellar physics

Inspired by the recent astronomical discovery of new diffused interstellar bands (DIBs) assigned to the electronic transitions in the naphthalene radical cation based on complementary laboratory measurements, we attempt here an ab initio quantum dynamical study to validate this assignment. In addition, the existence and mechanistic details of nonradiative deactivation of electronically excited polycyclic aromatic hydrocarbon (PAH) radical cations in the interstellar medium and their identity as carriers of DIBs are established here focusing on the prototypical naphthalene and anthracene radical cations of the PAH family.

Therapeutic uses of Swarnamakshika Bhasma (A Critical Review)

Mineral drugs play an important role in Ayurvedic therapeutics. Looking to the superiority of the metals and minerals to that of herbal and animal drugs, the Rasavaidyas went on experimenting clinical trials over lot of metals and minerals and systematically separated some of them which were exclusively active therapeutically. Swarnamakshika is one such mineral which after proper purification and incineration become highly potent and utilised for diseases like Jwara, Pandu, Prameha, Shwasa, Kasa, Kushtha, Anidra, Apasmar etc.

Anthropomorphic simulator for minimally invasive epicardial access procedures

We have developed a prototype, in vitro anthropomorphic model for simulating pressure-guided, subxiphoid access procedures done to enable minimally invasive epicardial cardiac procedures including treatments for ventricular tachycardia. Life-size replicas of the heart and lungs were modelled using anatomically accurate surrogates. The dynamic pressure-frequency profiles of simulated pericardial fluid surrounding the water-pumped replica heart were measured and validated against previously acquired human intrapericardial pressure observations (Pearson's r = 0.88, p < 0.001). In replicating access procedures for approaching and entering the pericardial space, the system produced physiologically appropriate pressure measurements at each intermediate point along the needle's insertion pathway. Details of construction and performance are presented and discussed.

Fungal endophytes in three medicinal plants of Lamiaceae

Three medicinal plants Ocimum sanctum, Ocimum bacilicum and Leucas aspera were screened to study endophytic diversity of the plants. Altogether 103 fungal endophytes belonging to fourteen genera were isolated. Leaves of all three medicinal plants were colonized by a great number of endophytic fungi. Leaves of O. sanctum were colonized by the most, that is, eleven endophytes. Highest Shannon-Wiener index (2.256) was exhibited by O. sanctum with the highest Simpson's diversity (0.8654) indicating great species specificity. O. bacilicum and L. aspera showed the highest similarity coefficient. Some fungal genera have been showed to be host specific. In the present study Curvularia sp., Hymenula sp., Tricoderma sp. and Tubercularia sp. exclusively colonized O. sanctum ; whereas Alternaria sp. and Spicaria sp. colonized only L. aspera .