First principles design of divacancy defected graphene nanoribbon based rectifying and negative differential resistance device

We have elaborately studied the electronic structure of 555-777 divacancy (DV) defected armchair edged graphene nanoribbon (AGNR) and transport properties of AGNR based two-terminal device constructed with one defected electrode and one N doped electrode, by using density functional theory and non-equilibrium Green's function based approach. The introduction of 555-777 DV defect into AGNRs, results in a shifting of the {\pi} and {\pi}* bands towards the higher energy value which indicates a shifting of the Fermi level towards the lower energy. Formation of a potential barrier, very similar to that of conventional p-n junction, has been observed across the junction of defected and N doped AGNR. The prominent asymmetric feature of the current in the positive and negative bias indicates the diode like property of the device with high rectifying efficiency within wide range of bias voltages. The device also shows robust negative differential resistance (NDR) with very high peak-to-valley ratio. The analysis of the shifting of the energy states of the electrodes and the modification of the transmission function with applied bias provides an insight into the nonlinearity and asymmetry observed in the I-V characteristics. Variation of the transport properties on the width of the ribbon has also been discussed.Comment: 28 Pages, 12 Figures and 1 tabl

Knowledge, attitude and belief about contraception in post-partum and post abortal women in a tertiary care centre

Background: In this modern era where women have achieved the highest positions in politics, corporate world and conquered the moon, on the other side she is still fighting for her right, i.e. health. For this the women should become economically independent. The concept of waiting for a son preference by the society should be discouraged. Postpartum and post abortal period are very crucial for a women especially for many of those belonging to the villages as this may be the only time she comes in contact with a health personnel. Hence counseling should be given to all patients at this time.Methods: We conducted a cross-sectional study in the department of obstetrics and gynecology of sir Sunder Lal hospital between August 2013 to October 2013. 230 post-partum and post abortal women were interrogated and counseled about various methods of contraception. Awareness about emergency contraception pill and MTPill was also noted.Results: Only 69% had heard about various methods of contraception. IUCD and OCP were known to most patients. Most patients knew about contraception from television and doctors. After counseling 97% patients wanted contraception. Most patients opted for IUCD, Barrier method and DepoProvera. 20% patients knew about emergency contraception pill and 34.4% patients about MTPill.Conclusions: There is lack of awareness of contraception, emergency contraception and medical abortion in women under study. Regular counseling is a must to all post-partum and post abortal women. Information should be provided about various methods and patients should be given a choice to choose the method of contraception

Long reach cantilevers for sub-cellular force measurements

Maneuverable, high aspect ratio poly 3-4 ethylene dioxythiophene (PEDOT) fibers are fabricated for use as cellular force probes that can interface with individual pseudopod adhesive contact sites without forming unintentional secondary contacts to the cell. The straight fibers have lengths between 5 and 40 μm and spring constants in the 0.07-23.2 nN μm-1 range. The spring constants of these fibers were measured directly using an atomic force microscope (AFM). These AFM measurements corroborate determinations based on the transverse vibrational resonance frequencies of the fibers, which is a more convenient method. These fibers are employed to characterize the time dependent forces exerted at adhesive contacts between apical pseudopods of highly migratory D. discoideum cells and the PEDOT fibers, finding an average terminal force of 3.1 ± 2.7 nN and lifetime of 23.4 ± 18.5 s to be associated with these contacts