Impact of nicotine dependence on self-efficacy and readiness to quit among tobacco consumers in rural areas.

Aim and Objectives: The aim of the present study was to determine the impact or effect of nicotine dependence on self-efficacy and readiness to quit. Materials and Method: The current study was performed using a cross-sectional descriptive questionnaire design among tobacco users visiting primary health care facilities in the rural Jaipur district. Jaipur district is divided into four directions: east, west, north, and south. From each direction, two PHCs were selected randomly based on suitable accessibility to patients. Sample size of study is 465. Out of 465 tobacco consumers, 238 were consuming a smoked form of tobacco, and 227 study participants were consuming a smokeless form of tobacco. Results: It was observed that the majority of study participants (145 (31%)) need smoke/smokeless tobacco within 5 minutes of waking up. With regards to internal stimuli, the majority of study participants (179 (38%)) and (203 (44%)) were not very sure that they would refrain from smoking when they were nervous and depressed. It was determined that quitting tobacco products was not at all important for 159 (34%) study participants. In regards to confidence in tobacco product quitting, only 79 (16%) of tobacco consumers were extremely confident. Conclusion: It was concluded that nicotine dependence impacts both self-efficacy and readiness to quit. It was determined that the higher the nicotine dependence, the less self-efficacy and the less would be the readiness to quit.

Unraveling Exciton-Plasmon Coupling and the PIRET Mechanism in Decorated Silicon Nanowires.

Exciton-plasmon coupling is a fascinating physical phenomenon that has been investigated in various metal semiconductor systems. Intentionally chosen silicon nanowires (SiNWs) systems act as a host material for providing exciton as well as silicon oxide as a thin dielectric. A clear blue-shift in photoluminescence (PL) peak and a significant increase in visible range absorption were observed for metal nanoparticle (MNP) decorated SiNWs (D-SiNWs) which signifies the presence of exciton-plasmon coupling. A further investigation reveals that the possibility of the occurrence of the plasmon-induced resonance energy transfer (PIRET) mechanism is higher. The PL intensity enhancement in Au-decorated SiNWs is higher (∼38 times) in comparison to that in Pt due to the presence of a strong and localized electric field of plasmons near the interface of metal and semiconductors. Moreover, splitting in PL for gold-decorated SiNWs might be due to the presence of dipole-quadrupole coupling along with dipole-dipole coupling, which further increases the strength of the PIRET mechanism.

On the Discrepancy between Local and Average Structure in the Fast Na+ Ionic Conductor Na2.9Sb0.9W0.1S4.

Aliovalent substitution is a common strategy to improve the ionic conductivity of solid electrolytes for solid-state batteries. The substitution of SbS43- by WS42- in Na2.9Sb0.9W0.1S4 leads to a very high ionic conductivity of 41 mS cm-1 at room temperature. While pristine Na3SbS4 crystallizes in a tetragonal structure, the substituted Na2.9Sb0.9W0.1S4 crystallizes in a cubic phase at room temperature based on its X-ray diffractogram. Here, we show by performing pair distribution function analyses and static single-pulse 121Sb NMR experiments that the short-range order of Na2.9Sb0.9W0.1S4 remains tetragonal despite the change in the Bragg diffraction pattern. Temperature-dependent Raman spectroscopy revealed that changed lattice dynamics due to the increased disorder in the Na+ substructure leads to dynamic sampling causing the discrepancy in local and average structure. While showing no differences in the local structure, compared to pristine Na3SbS4, quasi-elastic neutron scattering and solid-state 23Na nuclear magnetic resonance measurements revealed drastically improved Na+ diffusivity and decreased activation energies for Na2.9Sb0.9W0.1S4. The obtained diffusion coefficients are in very good agreement with theoretical values and long-range transport measured by impedance spectroscopy. This work demonstrates the importance of studying the local structure of ionic conductors to fully understand their transport mechanisms, a prerequisite for the development of faster ionic conductors.

Atypical hemolytic uremic syndrome (aHUS) responsive to mycophenolate mofetil: A case report from Nepal.

Introduction: An atypical hemolytic uremic syndrome is an extremely rare and life-threatening thrombotic microangiopathy. This disorder is caused by dysregulation of the alternative pathway of the complement system in association with genetic abnormalities or the development of autoantibodies. However, 30-50% of patients do not have genetic or acquired mutations in the complement system. Case report: Patient presented with fever and periorbital swelling. She had anemia, thrombocytopenia, and deranged liver function tests. Urinalysis revealed hematuria and proteinuria. Antibody tests and genetic analysis were negative. Renal biopsy revealed findings suggestive of thrombotic microangiopathy with predominantly glomerular involvement. Thus, the diagnosis of Atypical Hemolytic Uremic Syndrome, immunofluorescence negative, genetic negative, and anti-complement negative was made. Discussion: This article reports a case of atypical hemolytic uremic syndrome in a child with negative genetic analysis and anti-complement factor H antibody, which was treated successfully on steroid and mycophenolate mofetil. Early diagnosis along with prompt treatment and close monitoring will lead to recovery from atypical Hemolytic Uremic Syndrome. Conclusion: Although HUS is generally associated with genetic abnormalities or a positive antibody test, some patients with HUS may present atypically with negative genetic analysis and antibody tests.

Diverging Expressions of Anharmonicity in Halide Perovskites.

Lead-based halide perovskite crystals are shown to have strongly anharmonic structural dynamics. This behavior is important because it may be the origin of their exceptional photovoltaic properties. The double perovskite, Cs2 AgBiBr6 , has been recently studied as a lead-free alternative for optoelectronic applications. However, it does not exhibit the excellent photovoltaic activity of the lead-based halide perovskites. Therefore, to explore the correlation between the anharmonic structural dynamics and optoelectronic properties in lead-based halide perovskites, the structural dynamics of Cs2 AgBiBr6 are investigated and are compared to its lead-based analog, CsPbBr3 . Using temperature-dependent Raman measurements, it is found that both materials are indeed strongly anharmonic. Nonetheless, the expression of their anharmonic behavior is markedly different. Cs2 AgBiBr6 has well-defined normal modes throughout the measured temperature range, while CsPbBr3 exhibits a complete breakdown of the normal-mode picture above 200 K. It is suggested that the breakdown of the normal-mode picture implies that the average crystal structure may not be a proper starting point to understand the electronic properties of the crystal. In addition to our main findings, an unreported phase of Cs2 AgBiBr6 is also discovered below ≈37 K.

Testing the efficacy of sea urchin exclusion methods for restoring kelp.

Kelps are ecosystem engineers, which collectively form forests that provide a variety of important ecosystem services for humans and other organisms. Kelp forests are threatened by multiple local and global stressors, one of the most notable is herbivory. Overabundant sea; urchins can consume kelp, leading to a phase shift from productive forests to unproductive; rocky barrens. Reducing sea urchin densities by directly removing them can reverse this; phase shift. However, maintaining low densities of sea urchins, is logistically and financially; challenging. Following a review of herbivore exclusion methods to date, we tested the efficacy of three different methods for excluding sea urchins from kelp in the laboratory: flexible fences; electricity; and copper anti-fouling paint. The results from the laboratory; experiment showed that flexible fencing was the most successful method for excluding sea urchins. To test the efficacy of this method in the field, sea urchins were removed from 1m2 patches in barrens and intact kelp beds, and the effectiveness of flexible fences of two different heights (30 cm and 60 cm) at excluding sea urchins were tested. The results from the field study demonstrated that flexible fences of both heights were effective at maintaining low sea urchin densities in barrens but not in intact kelp beds, relative to unmanipulated; rocky barrens. These findings suggest that flexible fencing could be an important tool in restoring kelp in barrens, however the costs of fencing are likely to place limits on the scale at which this management strategy can be implemented.

Strongly Anharmonic Octahedral Tilting in Two-Dimensional Hybrid Halide Perovskites.

Recent investigations of two-dimensional (2D) hybrid organic-inorganic halide perovskites (HHPs) indicate that their optical and electronic properties are dominated by strong coupling to thermal fluctuations. While the optical properties of 2D-HHPs have been extensively studied, a comprehensive understanding of electron-phonon interactions is limited because little is known about their structural dynamics. This is partially because the unit cells of 2D-HHPs contain many atoms. Therefore, the thermal fluctuations are complex and difficult to elucidate in detail. To overcome this challenge, we use polarization-orientation Raman spectroscopy and ab initio calculations to compare the structural dynamics of the prototypical 2D-HHPs [(BA)2PbI4 and (PhE)2PbI4] to their three-dimensional (3D) counterpart, MAPbI3. Comparison to the simpler, 3D MAPbI3 crystal shows clear similarities with the structural dynamics of (BA)2PbI4 and (PhE)2PbI4 across a wide temperature range. The analogy between the 3D and 2D crystals allows us to isolate the effect of the organic cation on the structural dynamics of the inorganic scaffold of the 2D-HHPs. Furthermore, using this approach, we uncover the mechanism of the order-disorder phase transition of (BA)2PbI4 (274 K) and show that it involves relaxation of octahedral tilting coupled to anharmonic thermal fluctuations. These anharmonic fluctuations are important because they induce charge carrier localization and affect the optoelectronic performance of these materials.

Knowledge, attitude and reported practice regarding donning and doffing of personal protective equipment among frontline healthcare workers against COVID-19 in Nepal: A cross-sectional study.

BACKGROUND: Coronavirus Disease 2019 (COVID-19) is a respiratory infection with a high rate of transmission primarily via airborne route and direct contact. Proper use of personal protective equipment (PPE) is a proven and effective way to prevent COVID-19 spread in healthcare settings. This study was done aiming to assess the knowledge, attitude, and reported practice, and identify the associated factors regarding donning and doffing of PPE among frontline healthcare workers in Nepal. METHODS: A cross-sectional study was conducted from 25th April to 30th July 2021 among 205 frontline healthcare workers of Nepal selected randomly from among the contacts of the investigators. A structured self-administered questionnaire prepared in google form was used as a study tool and shared via social media to the participants to obtain information on socio-demographic and workplace characteristics along with their knowledge, attitude, and reported practice regarding donning and doffing of PPE. RESULT: A total of 79.5% of participants had satisfactory knowledge while 75.6% had satisfactory practice scores regarding donning and doffing of PPE. Factors such as the profession of the participants (p-value = 0.048), their workplace (p-value = 0.005), provision of PPE at workplace (p-value = 0 .009), and availability of designated space at workplace for methodical donning and doffing of PPE (p-value = 0.010) were significantly associated with satisfactory knowledge score whereas availability of designated space at workplace for donning and doffing of PPE was significantly associated with good practice score (p-value = 0.009). CONCLUSION: This study demonstrated an overall good knowledge, attitude, and reported practice regarding donning and doffing of PPE among frontline healthcare workers in Nepal. However, the reported shortcomings like poor knowledge regarding the sequence of donning and doffing and corresponding flawed practice behaviors need to be addressed.

Anisotropic nonlinear optical response in a graphene oxide-gold nanohybrid.

In this Letter, we report for the first time, to the best of our knowledge, the anisotropic optical response in a graphene oxide (GO)-gold (Au) nanohybrid. Polarization-sensitive nonlinear optical absorption measurements revealed that nanohybrids are highly anisotropic, (ß⊥-ß‖)≈28cm/GW, which is more than one order of magnitude higher than that of control GO (2 cm/GW). The first-principle analysis of absorbance at nanohybrid interfaces with varying functional ligand concentrations corroborates with the experimentally observed intrinsic linear anisotropy. Thus, this Letter enables new routes to realize smart and high-performing nonlinear optical systems selectively and directionally such as tunable optical limiters and optical data processing devices.

Ultrafast and low-power crystallization in Ge1Sb2Te4 and Ge1Sb4Te7 thin films using femtosecond laser pulses.

Rapid and reversible switching between amorphous and crystalline phases of phase-change material promises to revolutionize the field of information processing with a wide range of applications including electronic, optoelectronics, and photonic memory devices. However, achieving faster crystallization is a key challenge. Here, we demonstrate femtosecond-driven transient inspection of ultrafast crystallization of as-deposited amorphous Ge1Sb2Te4 and Ge1Sb4Te7 thin films induced by a series of 120 fs laser pulses. The snapshots of phase transitions are correlated with the time-resolved measurements of change in the absorption of the samples. The crystallization is attributed to the reiterative excitation of an intermediate state with subcritical nuclei at a strikingly low fluence of 3.19 mJ/cm2 for Ge1Sb2Te4 and 1.59 mJ/cm2 for Ge1Sb4Te7. Furthermore, 100% volumetric crystallization of Ge1Sb4Te7 was achieved with the fluence of 4.78 mJ/cm2, and also reamorphization is seen for a continuous stimulation at the same repetition rate and fluence. A systematic confirmation of structural transformations of all samples is validated by Raman spectroscopic measurements on the spots produced by the various excitation fluences.

Femtosecond laser-induced ultrafast transient snapshots and crystallization dynamics in phase change material.

We report here femtosecond laser-driven transient snapshots of ultrafast crystallization of Ge2Sb2Te5 films from its as-deposited amorphous phase, and the local structural change is validated by micro-Raman spectroscopy and x-ray diffraction. The decay time constant of ∼5 ps in transient spectra with a precise temporal resolution using 400 nm (pump) reveals about 68 volumetric percentage crystallization at a remarkably low fluence of 4.78 mJ·cm-2. This is attributed to reiterated excitation after a complete carrier relaxation and formation of a long-lasting transient phase at sub-threshold fluences. Furthermore, Raman spectra of irradiated spots confirm defective-octahedral modes at 110 and 160 cm-1 validating crystallization.

Saturable absorption in one-dimensional Sb2Se3 nanowires in the visible to near-infrared region.

One-dimensional (1D) free-standing nanowires are particularly important for carrier confinement in two dimensions, which provides a platform to explore the nonlinear optical phenomena at the nanoscale. In this Letter, we demonstrate saturable absorption in the resonant and above-bandgap excitations of both ns and fs pulses in 1D crystalline Sb2Se3 nanowires prepared by the facile hydrothermal method. Impressively, the average length of the nanowires extends to a few micrometers with a high aspect ratio of 300. The excited-state to ground-state absorption cross-section ratio in Sb2Se3 nanowires is ≈0.23, which suggests that they can be utilized as passive mode lockers.

Engineering the optical response of a-Se thin films by employing morphological disorder.

In this article, we experimentally demonstrate for the first time that photobleaching (PB) can be induced in morphologically disordered a-Se thin film, an observation which is opposite of the previously well-known photodarkening (PD) effects in morphologically ordered films. Further, the optical response of the film shows many fold increase with increase in control beam intensity. To explain the observed extraordinary phenomenon, we have proposed a model based on the morphological disorder of a modified surface and its subsequent photo-annealing. Our results demonstrate an efficient and yet simple new method to engineer the optical response of photosensitive thin films. We envision that this process can open up many avenues in optical field-enhanced absorption-based technologies.

First observation of the temperature-dependent light-induced response of Ge(25)As(10)Se(65) thin films.

Ge-rich ternary chalcogenide glasses (ChGs) exhibit photobleaching (PB) when illuminated with bandgap light. This effect originates from the combined effects of intrinsic structural changes and photo-oxidation. In a sharp contradiction to previous observations, in this Letter, we demonstrate, for the first time, that Ge-rich Ge(25)As(10)Se(65) ChG thin films exhibit photodarkening (PD) at 20 K and PB at 300 and 420 K after having been continuously illuminated for ∼3 hours. The temporal evolution of PD/PB shows distinct characteristics at the temperature of illumination, and provides valuable information on the light-induced structural changes. Furthermore, structure-specific far-infrared (FIR) absorption measurements give direct evidence of different structural units involved in PD/PB at the contrasting temperatures. By comparing the light-induced effects in vacuum and air, we conclude that intrinsic structural changes dominate over photo-oxidation in the observed PB in Ge(25)As(10)Se(65) ChG thin films.

Origin of Unusual Excitonic Absorption and Emission from Colloidal Ag2S Nanocrystals: Ultrafast Photophysics and Solar Cell.

Colloidal Ag2S nanocrystals (NCs) typically do not exhibit sharp excitonic absorption and emission. We first elucidate the reason behind this problem by preparing Ag2S NCs from nearly monodisperse CdS NCs employing cation exchange reaction. It was found that the defect-related midgap transitions overlap with excitonic transition, blurring the absorption spectrum. On the basis of this observation, we prepared nearly defect-free Ag2S NCs using molecular precursors. These defect-free Ag2S NCs exhibit sharp excitonic absorption, emission (quantum yield 20%) in near-infrared (853 nm) region, and improved performance of Ag2S quantum-dot-sensitized solar cells (QDSSCs). Samples with lower defects exhibit photoconversion efficiencies >1% and open circuit voltage of ∼0.3 V, which are better compared with prior reports of Ag2S QDSSCs. Femtosecond transient absorption shows pump-probe two-photon absorption above 630 nm and slow-decaying excited state absorption below 600 nm. Concomitantly, open-aperture z-scan shows strong two-photon absorption at 532 nm (coefficient 55 ± 3 cm/GW).