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Prolonged Exciton Lifetime Is Achieved in Porphyrin Nanoring by Template Engineering: A Nonadiabatic Tight Binding Approach. J Phys Chem Lett 2024; 15:4737-4744. [PMID: 38661142 DOI: 10.1021/acs.jpclett.4c00684] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Porphyrin nanoring has been attracting immense attention due to its light harvesting capacity and potential applications in optical, catalysis, sensor, and electronic devices. We demonstrate by nonadiabatic quantum dynamics simulations that the photovoltaic efficiency can be enhanced by template engineering. Altering the hexadentate template (T6) with two tridentate templates (2T3) within the porphyrin ring (P6) cavity accelerated the electron transfer twice and suppressed the electron-hole recombination by nearly three times. The atomistic tight-binding simulation rationalized the dynamics by different localizations of charge of the band edge states, changes in nonadiabatic coupling, alteration in quantum coherence, and involvement of diverse electron-phonon vibrational modes. Further 2T3 templates more strongly hold the P6 ring than T6, reducing the structural fluctuation. As a result, the nonadiabatic coupling becomes weaker and suppresses the carrier recombination. Current atomistic simulation presents a template engineering strategy to enhance the exciton lifetime along with ultrafast charge separation, crucial factors for photovoltaic applications.
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Controlling Charge Carrier Dynamics in Porphyrin Nanorings by Optically Active Templates. J Phys Chem Lett 2023; 14:11384-11392. [PMID: 38078872 PMCID: PMC10749466 DOI: 10.1021/acs.jpclett.3c03304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 12/01/2023] [Accepted: 12/01/2023] [Indexed: 12/22/2023]
Abstract
Understanding the dynamics of photogenerated charge carriers is essential for enhancing the performance of solar and optoelectronic devices. Using atomistic quantum dynamics simulations, we demonstrate that a short π-conjugated optically active template can be used to control hot carrier relaxation, charge carrier separation, and carrier recombination in light-harvesting porphyrin nanorings. Relaxation of hot holes is slowed by 60% with an optically active template compared to that with an analogous optically inactive template. Both systems exhibit subpicosecond electron transfer from the photoactive core to the templates. Notably, charge recombination is suppressed 6-fold by the optically active template. The atomistic time-domain simulations rationalize these effects by the extent of electron and hole localization, modification of the density of states, participation of distinct vibrational motions, and changes in quantum coherence. Extension of the hot carrier lifetime and reduction of charge carrier recombination, without hampering charge separation, demonstrate a strategy for enhancing efficiencies of energy materials with optically active templates.
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Measuring the Ultrafast Spectral Diffusion and Vibronic Coupling Dynamics in CdSe Colloidal Quantum Wells using Two-Dimensional Electronic Spectroscopy. ACS NANO 2023; 17:2411-2420. [PMID: 36706108 DOI: 10.1021/acsnano.2c09606] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
We measure the ultrafast spectral diffusion, vibronic dynamics, and energy relaxation of a CdSe colloidal quantum wells (CQWs) system at room temperature using two-dimensional electronic spectroscopy (2DES). The energy relaxation of light-hole (LH) excitons and hot carriers to heavy-hole (HH) excitons is resolved with a time scale of ∼210 fs. We observe the equilibration dynamics between the spectroscopically accessible HH excitonic state and a dark state with a time scale of ∼160 fs. We use the center line slope analysis to quantify the spectral diffusion dynamics in HH excitons, which contains an apparent sub-200 fs decay together with oscillatory features resolved at 4 and 25 meV. These observations can be explained by the coupling to various lattice phonon modes. We further perform quantum calculations that can replicate and explain the observed dynamics. The 4 meV mode is observed to be in the near-critically damped regime and may be mediating the transition between the bright and dark HH excitons. These findings show that 2DES can provide a comprehensive and detailed characterization of the ultrafast spectral properties in CQWs and similar nanomaterials.
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Symmetrical Linkage in Porphyrin Nanoring Suppressed the Electron-Hole Recombination Demonstrated by Nonadiabatic Molecular Dynamics. J Phys Chem Lett 2022; 13:7213-7219. [PMID: 35912962 DOI: 10.1021/acs.jpclett.2c02073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Macromolecular porphyrin nanorings are receiving significant attention because of their excellent optoelectronic properties. However, their efficiencies as potential solar materials are significantly affected by nonradiative charge recombination. To understand the recombination mechanism by alternating structural parameters and using tight-binding nonadiabatic molecular dynamics, we demonstrate that charge recombination depends strongly on the mode of the linker in the porphyrin nanoring. The nanoring having all-butadiyne-linkage (pristine-P8) inhibits carrier relaxation. In contrast, a partially fused nanoring (fused-P8) expedites the rate of quantum transition. An extension of the lifetime by a factor of 4 is due to the larger optical gap in pristine-P8 that reduces the NA coupling by decreasing the overlap between band edge states. Additionally, an intense phonon peak in the low-frequency region and rapid coherence loss within the electronic subsystem favors prolonging the carrier lifetime. This study provides an atomistic realization for the design of macromolecular porphyrin nanorings for the potential use in photovoltaic materials.
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P1389: RUXOLITINIB DEMONSTRATES A GREATER CORTICOSTEROID-SPARING EFFECT THAN BEST AVAILABLE THERAPY IN PATIENTS WITH CORTICOSTEROID-REFRACTORY/DEPENDENT CHRONIC GRAFT-VS-HOST DISEASE. Hemasphere 2022. [PMCID: PMC9429566 DOI: 10.1097/01.hs9.0000848416.66197.62] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
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Rapid detection of Actinobacillus pleuropneumoniae targeting the apxIVA gene for diagnosis of contagious porcine pleuropneumonia in pigs by Polymerase Spiral Reaction. Lett Appl Microbiol 2022; 75:442-449. [PMID: 35616177 DOI: 10.1111/lam.13749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2022] [Revised: 05/13/2022] [Accepted: 05/16/2022] [Indexed: 11/29/2022]
Abstract
Actinobacillus pleuropneumoniae is the primary etiological agent of contagious porcine pleuropneumonia associated with serious economic impact on pig husbandry worldwide. Diagnosis of the disease by existing techniques including isolation and identification bacteria followed by serotyping, serological techniques, conventional PCR, real-time PCR and LAMP assays are cumbersome, time consuming, costly and not suitable for rapid field application. A novel isothermal polymerase chain reaction (PSR) technique is standardized for all the reagents, incubation time and incubation temperature against A. pleuropneumoniae. Sensitivity of the assay was determined against various dilutions of purified DNA and total bacterial count. Specificity of the assay was determined against 11 closely related bacterial isolates. The relative sensitivity and specificity was compared with bacterial isolation, conventional PCR and real-time PCR assays. The PSR assay for specific detection was standardized at 64o C for 30 minutes incubation in a water bath. The result was visible by the naked eye after centrifugation of the reaction mixture or after incorporation of SYBR Green dye as yellow-green fluorescence. The technique was found to be 100% specific and equally sensitive with real-time PCR and 10 times more sensitive than conventional PCR. The PSR assay could be applicable in detection of the organisms in porcine nasal swabs spiked with A. pleuropneumoniae. This is the first ever report on development of PSR for specific detection of A. pleuropneumoniae and can be applied for early diagnosis at field level.
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Brine residues and organics in the Urvara basin on Ceres. Nat Commun 2022; 13:927. [PMID: 35194036 PMCID: PMC8863799 DOI: 10.1038/s41467-022-28570-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 01/24/2022] [Indexed: 11/09/2022] Open
Abstract
Ceres is a partially differentiated dwarf planet, as confirmed by NASA's Dawn mission. The Urvara basin (diameter ~170 km) is its third-largest impact feature, enabling insights into the cerean crust. Urvara's geology and mineralogy suggest a potential brine layer at the crust-mantle transition. Here we report new findings that help in understanding the structure and composition of the cerean crust. These results were derived by using the highest-resolution Framing Camera images acquired by Dawn at Ceres. Unexpectedly, we found meter-scale concentrated exposures of bright material (salts) along the crater's upper central ridge, which originate from an enormous depth, possibly from a deep-seated brine or salt reservoir. An extended resurfacing modified the southern floor ~100 Myr after crater formation (~250 Myr), long after the dissipation of the impact-generated heat. In this resurfaced area, one floor scarp shows a granular flow pattern of bright material, showing spectra consistent with the presence of organic material, the first such finding on Ceres beyond the vast Ernutet area. Our results strengthen the hypothesis that Ceres is and has been a geologically active world even in recent epochs, with salts and organic-rich material playing a major role in its evolution.
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Extensive study of radiation dose on human body at aviation altitude through Monte Carlo simulation. LIFE SCIENCES IN SPACE RESEARCH 2021; 31:1-13. [PMID: 34689941 DOI: 10.1016/j.lssr.2021.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Revised: 07/06/2021] [Accepted: 07/07/2021] [Indexed: 06/13/2023]
Abstract
The diverse near-Earth radiation environment due to cosmic rays and solar radiation has direct impact on human civilization. In the present and upcoming era of increasing air transfer, it is important to have precise idea of radiation dose effects on human body during air travel. Here, we calculate the radiation dose on the human body at the aviation altitude, also considering the shielding effect of the aircraft structure, using Monte Carlo simulation technique based on Geant4 toolkit. We consider proper 3D mathematical model of the atmosphere and geomagnetic field, updated profile of the incoming particle flux due to cosmic rays and appropriate physics processes. We use quasi-realistic computational phantoms to replicate the human body (male/female) for the effective dose calculation and develop a simplified mathematical model of the aircraft (taking Boeing 777-200LR as reference) for the shielding study. We simulate the radiation environment at the flying altitude (at 10 km and considering geomagnetic latitude in the range of 45-50°), as well as at various locations inside the fuselage of the aircraft. Then, we calculate the dose rates in the different organs for both male and female phantoms, based on latest recommendations of International Commission on Radio logical Protection. This calculation shows that the sex-averaged effective dose rate in human phantom is 5.46 μSv/h, whereas, if we calculate weighted sum of equivalent dose contributions separately in female and male body: total weighted sum of equivalent dose rate received by the female phantom is 5.72 μSv/h and that by the male phantom is 5.20 μSv/h. From the simulation, we also calculate the numerous cosmogenic radionuclides produced inside the phantoms through activation or spallation processes which may induce long-term biological effects.
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Arene and functionalized arene based two dimensional organic-inorganic hybrid perovskites for photovoltaic applications. J Comput Chem 2021; 42:1982-1990. [PMID: 34390256 DOI: 10.1002/jcc.26731] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/23/2021] [Accepted: 07/25/2021] [Indexed: 11/12/2022]
Abstract
Recently, two-dimensional organic-inorganic hybrid perovskites have attracted great attention for their outstanding performances in solar energy conversion devices. By using first principles calculations, we explored the structural, electronic and optical properties of recently synthesized (PEA)2 PbI4 and (PEA)2 SnI4 organic-inorganic hybrid perovskites to understand the photovoltaic performances of these systems. Our study reveals that both the perovskites are direct band gap semiconductors and possess desirable band gap for solar energy absorption. We have further extended our study to fluoro-, chloro-, and bromo-functionalized phenethylammonium (PEA) cations based [X(X = F, Cl, Br)PEA]2 A(A = Pb, Sn)I4 perovskite materials. The halogenated benzene moiety confers an ultrahydrophobic character and protects the perovskites from ambient moisture. The halogen functionalized perovskites remain direct band gap semiconductors and all the perovskites show very strong optical absorption (∼7 × 105 cm-1 ) across UV-visible region. We have further calculated the photo-conversion efficiency (PCE) of both arene and functionalized arene based perovskites. The halogen-functionalized PEA-based perovskites also exhibit high PCE as like pristine ones and finally achieve high PCE of up to 24.30%, making them competitive with other previously reported perovskite-based photovoltaic devices.
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Common Defects Accelerate Charge Separation and Reduce Recombination in CNT/Molecule Composites: Atomistic Quantum Dynamics. J Am Chem Soc 2021; 143:6649-6656. [PMID: 33896175 DOI: 10.1021/jacs.1c02325] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Carbon nanotubes (CNTs) are appealing candidates for solar and optoelectronic applications. Traditionally used as electron sinks, CNTs can also perform as electron donors, as exemplified by coupling with perylenediimide (PDI). To achieve high efficiencies, electron transfer (ET) should be fast, while subsequent charge recombination should be slow. Typically, defects are considered detrimental to material performance because they accelerate charge and energy losses. We demonstrate that, surprisingly, common CNT defects improve rather than deteriorate the performance. CNTs and other low dimensional materials accommodate moderate defects without creating deep traps. At the same time, charge redistribution caused by CNT defects creates an additional electrostatic potential that increases the CNT work function and lowers CNT energy levels relative to those of the acceptor species. Hence, the energy gap for the ET is decreased, while the gap for the charge recombination is increased. The effect is particularly important because charge acceptors tend to bind near defects due to enhanced chemical interactions. The time-domain simulation of the excited-state dynamics provides an atomistic picture of the observed phenomenon and characterizes in detail the electronic states, vibrational motions, inelastic and elastic electron-phonon interactions, and time scales of the charge separation and recombination processes. The findings should apply generally to low-dimensional materials, because they dissipate defect strain better than bulk semiconductors. Our calculations reveal that CNT performance is robust to common defects and that moderate defects are essential rather than detrimental for CNT application in energy, electronics, and related fields.
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Lymphocyte subsets in the small intestine of piglets fed with probiotic and zinc: a qualitative and quantitative micro-anatomical study. Folia Morphol (Warsz) 2021; 81:82-90. [PMID: 33438190 DOI: 10.5603/fm.a2020.0148] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 11/25/2022]
Abstract
BACKGROUND Piglet mortality is a real concern to the pig farmers. The major cause is due to the late maturation of the immune system and dietary changes in post-weaned piglets. The potential role of probiotic and zinc in the stimulation of the immune system is well established. Hence, the present study was undertaken to evaluate alterations of T and B cells in the small intestine after dietary inclusion of probiotic and zinc in pre and post-weaned piglets. MATERIALS AND METHODS A total of 18 healthy LWY piglets, irrespective of sex obtained from 3 litters at the age-group of 20, 30 and 60 days. They were divided into a control group fed with basal diet and a treatment group fed with probiotic and zinc supplement along with the basal diet, consisting of three animals in each group. The piglets were weaned at 28 days of age. After sacrificing the animals at day 20, 30 and 60 from both the groups, the abdominal cavity was opened and small intestinal tissue samples were collected, processed and stained by indirect immunofluorescence technique. The slides were evaluated under the fluorescent light microscope. The data were statistically analyzed. RESULTS The different T and B cell subsets were recorded in the lining epithelium, core of villus, crypt area of LP and PP area. The number of CD4+, CD8+, IgA+ and IgM+ cells was higher in the treated piglets than the control group of animals, irrespective of segments of intestine and age-group. CONCLUSIONS It can be concluded that the dietary supplementation of probiotic and zinc was found to be good additives as they can stimulate the immune response in piglets, especially during the critical early post-weaning period.
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Effectiveness of cyclosporine A in patients with moderate to severe plaque psoriasis in a real-life clinical setting in Italy: the TRANSITION study. J DERMATOL TREAT 2020; 33:401-407. [PMID: 32349568 DOI: 10.1080/09546634.2020.1757017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Background: Cyclosporine A (CsA) is one of the systemic therapeutic options for moderate-to-severe psoriasis, based on its efficacy and rapidity of action. The current study investigated the response to CsA in patients with moderate-to-severe plaque psoriasis.Materials and Methods: TRANSITION was an observational, cross-sectional, multicentre study which evaluated the proportion of partial- and suboptimal-responders among patients with moderate-to-severe plaque psoriasis treated with continuous CsA for ≥12 weeks. Patients demonstrating a Psoriasis Area and Severity Index (PASI) response of ≥90, ≥75 and <90, ≥50 and <75 and <50 were defined as responders, suboptimal-responders, partial-responders, and non-responders, respectively.Results: A total of 196 patients (mean age, 46.6 years; 62.8% males) from 14 sites in Italy were evaluated. At the study visit, the mean (SD) PASI score was 4.2(5.5) compared with 15.3(7.1) prior to the last CsA cycle. For response categories, 39.8%, 22.4%, 16.8%, and 20.9% of patients were responders, suboptimal-responders, partial-responders, and non-responders to CsA treatment. Overall, 28.6% of patients permanently discontinued treatment with CsA (lack of efficacy [10.2%], poor tolerability and voluntary discontinuation [3.6% each], and other [11.7%]).Conclusion: Patients were only partially satisfied with CsA treatment, reporting measurable impact on quality of life. Only 40% patients showed a satisfactory response to CsA.
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Structural rigidity accelerates quantum decoherence and extends carrier lifetime in porphyrin nanoballs: a time domain atomistic simulation. NANOSCALE ADVANCES 2020; 2:1502-1511. [PMID: 36132296 PMCID: PMC9419611 DOI: 10.1039/d0na00001a] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2020] [Accepted: 02/18/2020] [Indexed: 06/15/2023]
Abstract
Nonradiative electron-hole (e-h) recombination is the primary source of energy loss in photovoltaic cells and inevitably, it competes with the charge transfer process, leading to poor device performance. Therefore, much attention has to be paid for delaying such processes; increasing the excitonic lifetime may be a solution for this. Using the real-time, density functional tight-binding theory (DFTB) combined with nonadiabatic molecular dynamics (NAMD) simulations, we demonstrate the exciton relaxation phenomena of different metal-centered porphyrin nanoballs, which are supposed to be very important for the light-harvesting process. It has been revealed that the carrier recombination rate gradually decreases with the increase in the molecular stiffness by introducing metal-coordinating templating agents into the nanoball. Our simulation demonstrates that the lower atomic fluctuations lead to poorer electron-phonon nonadiabatic coupling in association with weak phonon modes and these as a whole are responsible for shorter quantum coherence and hence delayed recombination events. Our analysis is in good agreement with the recent experimental observation. By replacing the Zn metal center with a heavier Cd atom, a similar trend is observed; however, the rate slows down abruptly. The present simulation study provides the fundamental mechanism in detail behind the undesired energy loss during exciton recombination and suggests a rational design of impressive nanosystems for future device fabrication.
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Engineering the magnetic properties of PtSe 2 monolayer through transition metal doping. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2019; 31:145502. [PMID: 30650400 DOI: 10.1088/1361-648x/aaff40] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Using first-principles calculations, we have studied the energetic feasibility and magnetic properties of transition metal (TM) doped PtSe2 monolayers. Our study shows that TM doped PtSe2 layers with 6.25% doping exhibit versatile spintronic behaviour depending on the nature of the dopant TM atoms. Groups IVB and VIII10 TM doped PtSe2 layers are non magnetic semiconductors, while groups IIIB, VB, VIII8, VIII9, IB TM doped PtSe2 layers are half-metals and finally, groups VIB, VIIB and IIB TM doped PtSe2 layers are spin polarized semiconductors. The presence of half-metallic and magnetic semiconducting characteristics suggest that TM doped PtSe2 layers can be considered as a new kind of dilute magnetic semiconductor and thus have the promise to be used in spintronics. By studying the magnetic interactions between two TM dopants in PtSe2 monolayers for dopant concentration of 12.5% and dopant distance of 12.85 [Formula: see text], we have found that in particular, Fe and Ru doped PtSe2 systems are ferromagnetic half-metal having above-room-temperature Curie point of 422 and 379.9 K, respectively. By varying the dopant distance and concentration we have shown that the magnetic interaction is strongly dependent on dopant distance and concentration. Interestingly, the Curie temperature of TM doped PtSe2 layers is affected by the correlation effects on the TM d states and also spin-orbit coupling. We have also studied the magnetic properties of defect complex composed of one TM dopant and one Pt vacancy (TMPt + VPt) which shows novel magnetism.
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Argon plasma coagulation is an effective treatment for chronic radiation proctitis in gynaecological malignancy: an observational study. Colorectal Dis 2019; 21:465-471. [PMID: 30585689 DOI: 10.1111/codi.14541] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 11/12/2018] [Indexed: 12/31/2022]
Abstract
AIM Chronic radiation proctitis (CRP) develops in 5-15% of patients after pelvic radiation therapy, with rectal bleeding being the main symptom. Reports suggest that argon plasma coagulation (APC) can be an effective therapy for CRP following radiotherapy for prostate cancer, but there is less information about how useful it is after radiotherapy for gynaecological malignancy. The aim of this work therefore was to study the efficacy of APC for CRP after radiotherapy for gynaecological malignancy. METHOD This was a prospective study of consecutive patients with CRP following radiotherapy for gynaecological malignancy at IPGME&R, SDLD, Kolkata, India; symptoms included rectal bleeding grade (RBG) ≥ 2. APC was performed at monthly intervals to a maximum of four treatment sessions. Severity of disease at baseline was graded (endoscopically) by the total colonoscopic severity score (TCSS) and treatment response was assessed by reduction in RBG from ≥ 2 to ≤ 1 measured at > 6 months after cessation of APC. RESULTS Seventy patients [90% with cervical cancer, 10% with endometrial cancer; mean age 51.93 ± 9.15 years; median RBG 3 (range 2-4)] received APC. Seven patients died due to underlying malignancy and seven patients were lost to follow-up. Fifty-six (85.7%) patients responded to therapy after a median of 2 (range 1-4) treatment sessions. Multivariate analysis demonstrated that a lower haemoglobin at the start of treatment predicted failure of therapy (P < 0.05). CONCLUSION APC is an effective management option for CRP in female patients with gynaecological malignancy. However, the more anaemic the patient the less likely it is to be successful.
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Unambiguous hydrogenation of CO2 by coinage-metal hydride anions: an intuitive idea based on in silico experiments. Phys Chem Chem Phys 2019; 21:7483-7490. [DOI: 10.1039/c9cp00133f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Coinage metal hydride anions, especially AgH−, can effectively and deterministically hydrogenate CO2 to HCO2−.
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Periodically-ordered one and two dimensional CdTe QD superstructures: a path forward in photovoltaics. Phys Chem Chem Phys 2019; 21:19391-19402. [DOI: 10.1039/c9cp03529j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
By using the state-of-the-art theoretical method, we herein explore the potentiality of covalently linked periodically-ordered 1D chain, 2D hexagonal and square ordered superstructures of CdTe QDs in photovoltaics.
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Controlling the charge transfer and recombination dynamics in hollow ZnO QD based dye sensitized solar cell: An insight from ab initio simulation. Chem Phys Lett 2018. [DOI: 10.1016/j.cplett.2018.08.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Anomalous Hall effect in Weyl semimetal half-Heusler compounds RPtBi (R = Gd and Nd). Proc Natl Acad Sci U S A 2018; 115:9140-9144. [PMID: 30154165 PMCID: PMC6140499 DOI: 10.1073/pnas.1810842115] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Topological materials ranging from topological insulators to Weyl and Dirac semimetals form one of the most exciting current fields in condensed-matter research. Many half-Heusler compounds, RPtBi (R = rare earth), have been theoretically predicted to be topological semimetals. Among various topological attributes envisaged in RPtBi, topological surface states, chiral anomaly, and planar Hall effect have been observed experimentally. Here, we report an unusual intrinsic anomalous Hall effect (AHE) in the antiferromagnetic Heusler Weyl semimetal compounds GdPtBi and NdPtBi that is observed over a wide temperature range. In particular, GdPtBi exhibits an anomalous Hall conductivity of up to 60 Ω-1⋅cm-1 and an anomalous Hall angle as large as 23%. Muon spin-resonance (μSR) studies of GdPtBi indicate a sharp antiferromagnetic transition (TN) at 9 K without any noticeable magnetic correlations above TN Our studies indicate that Weyl points in these half-Heuslers are induced by a magnetic field via exchange splitting of the electronic bands at or near the Fermi energy, which is the source of the chiral anomaly and the AHE.
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Ultrafast, asymmetric charge transfer and slow charge recombination in porphyrin/CNT composites demonstrated by time-domain atomistic simulation. NANOSCALE 2018; 10:12683-12694. [PMID: 29946626 DOI: 10.1039/c8nr02544d] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
The versatile photochemical properties of porphyrin molecules make them excellent candidates for solar energy applications. Carbon nanotubes (CNTs) exhibit superior charge conductivity and have been combined with porphyrins to achieve efficient and ultrafast charge separation. Experiments show that the charge separated state lives less than 10 ps, which is too short for applications. Using real-time time-dependent tight binding density functional theory (DFTB) combined with non-adiabatic molecular dynamics (NAMD), we model photo-induced charge separation and recombination in two porphyrin/CNT composites. Having achieved excellent agreement with the experiment for the electron transfer from the porphyrins to the CNT, we demonstrate that hole transfer can be achieved upon CNT excitation, although in a less efficient way. By exciting the CNT one can extend light harvesting into lower energies of the solar spectrum and increase solar light conversion efficiency. We also show that the charge separated state can live over 1 ns. The two orders of magnitude difference from the experimental lifetime could arise due to the presence of defects or metallic tubes in the samples. The charge separated state is long-lived because the non-adiabatic electron-phonon coupling is very small, less than 1 meV, and the quantum coherence is short, 15-20 fs. The excited states in the isolated porphyrins and CNT live around 100 ps, in agreement with experiments as well. The porphyrin/CNT interaction occurs through the π-electron systems of the two species. The non-radiative relaxation is promoted by both high and low frequency phonons, with higher frequency phonons playing more important roles in electron relaxation than in hole relaxation. Low frequency phonons contribute significantly to the decay of the charge separated state, because they modulate the relative positions of the porphyrins and the CNT. The time-domain atomistic simulations provide a detailed understanding of the charge separation and recombination mechanisms, and generate valuable guidelines for the optimization of photovoltaic efficiency in modern nanoscale materials.
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Computational design of some TTF-substituted acene-based dyes for solar cell application using hollow ZnO quantum dot as acceptor. COMPUT THEOR CHEM 2018. [DOI: 10.1016/j.comptc.2018.05.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Proteomic analysis reveals that sulfamethoxazole induces oxidative stress in M. tuberculosis. Tuberculosis (Edinb) 2018; 111:78-85. [DOI: 10.1016/j.tube.2018.05.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/27/2018] [Accepted: 05/15/2018] [Indexed: 02/04/2023]
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Comparative Study between the Use of Multidose Standard Cardioplegia and Long Acting Del Nido Cardioplegia during Intracardiac Repair for Tetralogy of Fallot in Pediatric Patients. Mymensingh Med J 2018; 27:610-616. [PMID: 30141453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Pediatric myocardium is unique from mature myocardium; thus, the use of adult cardioplegia for pediatric cardiac operations may provide suboptimal myocardial protection. It is found that children undergoing heart surgery show evidence of less myocardial damage when del Nido cardioplegia is used instead of a standard cardioplegic solution. Del Nido cardioplegia solution provides a depolarized hyperkalaemic arrest lasting up to 60 minutes, reduces spontaneous and inducible activity during arrest, and prevents hyper contraction during early reperfusion. In this single blind randomized trial, a total of 60 patients underwent intra cardiac repair for TOF in National Institute of Cardiovascular Diseases, Dhaka, Bangladesh from July 2014 to January 2016 fulfilling inclusion and exclusion criteria. They were randomly assigned in two groups- 30 patients in Del Nido group (Group A) and 30 patients in standard group (Group B). Comparison between groups was done by Chi square test and Student's test. All data were analyzed by SPSS 20.0 for windows. P value less than 0.05 was considered as significant. There was statistically significant difference among the patients in terms of mean total initial cardioplegia volume, mean number of additional dose, mean additional dose amount, mean cross clamp time, mean CPB time (331.67±188.07 vs. 458.67±226.62, p=0.022; 0.13±0.35 vs. 1.27±0.89, p=0.000; 23.33±60.76 vs. 336.83±259.6, p=0.000; 45.10±10.35 vs. 59.23±23.21, p=0.003; 89.30±15.73 vs. 111.10±29.23, p=0.001 respectively). Mean post operative serum troponin I level at arrival in ICU and after 24 hours between two groups were statistically significantly different (55.60±32.91 vs. 83.5±58.99; p=0.024 and 13.01±5.84 vs. 18.16±9.51; p=0.014 respectively). The mean ventilation duration, mean ICU stay were also statistically significant. This study showed that cardiac arrest with Del Nido cardioplegia during intra cardiac repair for TOF was associated with improved myocardial protection over standard cardioplegia in terms of reduced CPB and cross clamp times, lower total volume of cardioplegia.
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Abstract
The iron-based high temperature superconductors exhibit a rich phase diagram reflecting a complex interplay between spin, lattice, and orbital degrees of freedom. The nematic state observed in these compounds epitomizes this complexity, by entangling a real-space anisotropy in the spin fluctuation spectrum with ferro-orbital order and an orthorhombic lattice distortion. A subtle and less-explored facet of the interplay between these degrees of freedom arises from the sizable spin-orbit coupling present in these systems, which translates anisotropies in real space into anisotropies in spin space. We present nuclear magnetic resonance studies, which reveal that the magnetic fluctuation spectrum in the paramagnetic phase of BaFe2As2 acquires an anisotropic response in spin-space upon application of a tetragonal symmetry-breaking strain field. Our results unveil an internal spin structure of the nematic order parameter, indicating that electronic nematic materials may offer a route to magneto-mechanical control. A fundamental understanding of nematic order is one of the most important issues to explore in the high temperature superconductors. Here, the authors unveil an internal spin structure of the nematic order in BaFe2As2 by using nuclear magnetic resonance under precisely controlled tunable strain.
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Restoration of Acutely Thrombosed Arterio-Venous Fistulae by rTPA and Percutaneous Angioplasty. J Vasc Access 2018; 2:150-3. [PMID: 17638279 DOI: 10.1177/112972980100200404] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Acute thrombosis in native arterio-venous fistulae (AVF) results in considerable patient morbidity. Interventional radiology (IR) comprising thrombolysis and percutaneous transluminal angioplasty (PTA) is well established in the management of thrombosed polytetrafluoroethylene (PTFE) grafts. However its role in thrombosed AVF is uncertain. We looked retrospectively at the role of IR in re-establishing blood flow in acutely thrombosed AVF. Between 1992–2000, 21 episodes of acutely thrombosed AVF in 15 patients (9 females; age range 29–80yrs) were referred for intervention. All fistulae were being used for haemodialysis at the time. Diagnosis was established by angiography and thrombolysis with recombinant tissue plasminogen activator (rTPA) was attempted in all patients. Discrete stenoses when present (n=12) were then treated with PTA and resistant or recurrent stenoses were managed by stent insertion (n=3). Patients were then heparinised for 24 hours. Technical success as defined by radiological patency was achieved in 86% cases. Clinical success i.e. the ability to reuse of the fistula for haemodialysis was achieved in 62% of the interventions, where patency rates at 3 and 6 months were 92% and 69% respectively. Five patients had recurrence of thrombosis >3 months after the primary procedure, 3 had successful re-intervention. Minor local bleeding was the only complication. Our retrospective study shows rTPA and PTA is successful in the management of acutely thrombosed AVF. We advocate the routine use of IR as a valuable technique for prolonging the life of native AVF in patients on maintenance haemodialysis.
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Macroscopic phase separation of superconductivity and ferromagnetism in Sr 0.5Ce 0.5FBiS 2-x Se x revealed by μSR. Sci Rep 2017; 7:17370. [PMID: 29234110 PMCID: PMC5727222 DOI: 10.1038/s41598-017-17637-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2017] [Accepted: 11/28/2017] [Indexed: 11/24/2022] Open
Abstract
The compound Sr0.5Ce0.5FBiS2 belongs to the intensively studied family of layered BiS2 superconductors. It attracts special attention because superconductivity at Tsc = 2.8 K was found to coexist with local-moment ferromagnetic order with a Curie temperature TC = 7.5 K. Recently it was reported that upon replacing S by Se TC drops and ferromagnetism becomes of an itinerant nature. At the same time Tsc increases and it was argued superconductivity coexists with itinerant ferromagnetism. Here we report a muon spin rotation and relaxation study (μSR) conducted to investigate the coexistence of superconductivity and ferromagnetic order in Sr0.5Ce0.5FBiS2−xSex with x = 0.5 and 1.0. By inspecting the muon asymmetry function we find that both phases do not coexist on the microscopic scale, but occupy different sample volumes. For x = 0.5 and x = 1.0 we find a ferromagnetic volume fraction of ~8 % and ~30 % at T = 0.25 K, well below TC = 3.4 K and TC = 3.3 K, respectively. For x = 1.0 (Tsc = 2.9 K) the superconducting phase occupies most (~64 %) of the remaining sample volume, as shown by transverse field experiments that probe the Gaussian damping due to the vortex lattice. We conclude ferromagnetism and superconductivity are macroscopically phase separated.
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ZIKV infection regulates inflammasomes pathway for replication in monocytes. Sci Rep 2017; 7:16050. [PMID: 29167459 PMCID: PMC5700238 DOI: 10.1038/s41598-017-16072-3] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 11/07/2017] [Indexed: 12/14/2022] Open
Abstract
ZIKV causes microcephaly by crossing the placental barrier, however, the mechanism of trans-placental dissemination of ZIKV remains unknown. Here, we sought to determine whether monocytes, which can cross tissue barriers, assist ZIKV dissemination to the fetus. We determined this by infecting monocytes with two strains of ZIKV: South American (PRVABC59) and Nigerian (IBH30656) and analyzing viral replication. We found that ZIKV infects and replicates in monocytes and macrophages, which results in the modulation of a large number of cellular genes. Analysis of these genes identified multiple pathways including inflammasome to be targeted by ZIKV, which was confirmed by analyzing the transcript levels of the proteins of inflammasome pathways, NLRP3, ASC, caspase 1, IL-1 and IL-18. Interestingly, IFNα and the IFN inducible gene, MxA were not enhanced, suggesting prevention of innate antiviral defense by ZIKV. Also, inhibition of inflammasome led to an increased transcriptional activity of IFNα, MxA and CXCL10. Based on these results we suggest that ZIKV transcription is regulated by inflammasomes.
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Nuclear magnetic resonance probe head design for precision strain control. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2017; 88:103902. [PMID: 29092471 DOI: 10.1063/1.5002631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
We present the design and construction of an NMR probe to investigate single crystals under strain at cryogenic temperatures. The probe head incorporates a piezoelectric-based apparatus from Razorbill Instruments that enables both compressive and tensile strain tuning up to strain values on the order of 0.3% with a precision of 0.001%. 75As NMR in BaFe2As2 reveals large changes to the electric field gradient and indicates that the strain is homogeneous to within 16% over the volume of the NMR coil.
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Rotavirus and other Diarrheal Disease in a Birth Cohort from Southern Indian Community. Indian Pediatr 2017; 53:583-8. [PMID: 27508534 DOI: 10.1007/s13312-016-0892-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVE To describe the incidence, severity and etiology of diarrheal disease in infants and young children residing in an urban slum community in Southern India. SETTING Three contiguous urban slums in Vellore, Tamil Nadu. PARTICIPANTS 452 children participating in a birth cohort study on diarrheal disease; 373 completed three years of follow-up. OUTCOME MEASURES Diarrheal incidence (obtained by twice-weekly home visits) and severity (assessed by the Vesikari scoring system), and etiological agents associated with diarrhea (through examination of stool specimens by bacteriologic culture, rotavirus enzyme immunoassay, PCR for norovirus and microscopy for parasites). RESULTS A total of 1856 diarrheal episodes were reported in 373 children. The overall incidence rate of diarrhea was 1.66 episodes per child year for three years, with 2.76 episodes per child year in infancy. The incidence peaked during the months of July and August. Severe diarrhea formed 8% of the total episodes. Rotavirus was the most common pathogen detected, being identified in 18% of episodes. Good hygiene status resulted in 33% protection against moderate-to-severe diarrhea. CONCLUSIONS This study highlights the burden of diarrheal disease and the important etiological agents of childhood diarrhea in Southern India. Promotion of hygienic behavior through health education may help reduce diarrheal incidence in this and similar communities.
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Curcumin Boosts up the Efficacy of Imatinib Mesylate in Chronic Myelogenic Leukemia Cell Line K-562 by Modulation of Various Markers. ACTA ACUST UNITED AC 2016. [DOI: 10.20546/ijcmas.2016.512.026] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Study on Airborne Heavy Metals in Industrialized Urban Area of Delhi, India. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2016; 97:798-805. [PMID: 27743040 DOI: 10.1007/s00128-016-1944-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2016] [Accepted: 09/30/2016] [Indexed: 06/06/2023]
Abstract
This study assessed the concentrations of airborne heavy metals (HMs) in particulate matter with a cutoff size of 10 µm (i.e., PM10) in an industrialized urban area (Naraina Industrial Area) of New Delhi, India. The samples were collected from January to December, 2011. The annual mean concentrations of selected HMs were as follows As (0.002 ± 0.002), Cd (0.030 ± 0.020), Co (0.003 ± 0.002), Cr (0.170 ± 0.081), Cu (0.183 ± 0.120), Fe (4.774 ± 1.889), Mn (0.258 ± 0.145), Ni (0.170 ± 0.146), Pb (0.345 ± 0.207) and Zn (1.806 ± 1.042) µg/m3. The seasonal trend for HMs followed the order postmonsoon > winter > premonsoon > monsoon. Principal component analysis-multiple linear regression (PCA-MLR) suggested the three major emission sources: industrial emission (70 %), mobile and stationary combustion sources (16 %), and suspended/re-suspended dust (14 %). Mean seasonal concentrations of PM10 exceeded both the 24-hour and annual Indian National Ambient Air Quality Standards (NAAQS) of 60 and 100 µg/m3, respectively, in all four seasons. Mean seasonal Ni concentrations in Delhi ambient air also exceeded the 24-h annual NAAQS of 0.020 µg/m3 during all four seasons. Mean Pb concentrations exceeded the annual NAAQS of 0.50 µg/m3 only during the post monsoon season. The high levels of Ni- and Pb-contaminated PM10 would appear to present the possibility of significant health risks.
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An Interesting Case of Basal Cell Carcinoma with Raynaud's Phenomenon Following Chronic Arsenic Exposure. JNMA J Nepal Med Assoc 2016; 55:100-102. [PMID: 28029677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2023] Open
Abstract
Arsenic is commonly known to be associated with squamous cell carcinoma. Among the lesser known associations is basal cell carcinoma and even rarer is its effect on blood vessels causing peripheral vascular disease. Here we present a case of a 55 yr old man with ulceroproliferative lesions on scalp and forehead along with several hyperpigmented patches on trunk and extremities. He had symptoms suggestive of Raynaud's phenomenon that eventually led to digital gangrene. FNAC was done which was suggestive of basal cell carcinoma. On further enquiry, he was found to reside in an arsenic endemic zone and was investigated for blood arsenic level which was elevated. Punch biopsy from different lesions from body confirmed nodular basal cell carcinoma. Presently the patient has stopped drinking water from the local tubewell. On follow-up he shows improvement of Raynaud's phenomenon and skin lesions.
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Local, atomic-level elastic strain measurements of metallic glass thin films by electron diffraction. Ultramicroscopy 2016; 165:51-8. [DOI: 10.1016/j.ultramic.2016.04.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2016] [Revised: 04/05/2016] [Accepted: 04/08/2016] [Indexed: 11/24/2022]
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Isoelectronically doped CdSe/Te nanoalloys as alternative solar cell materials: insight from computational analysis. RSC Adv 2016. [DOI: 10.1039/c6ra17778f] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
CdSe/Te nanoalloy as a solar energy harvesting material.
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New upper limit on strange quark matter abundance in cosmic rays with the PAMELA space experiment. PHYSICAL REVIEW LETTERS 2015; 115:111101. [PMID: 26406816 DOI: 10.1103/physrevlett.115.111101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Indexed: 06/05/2023]
Abstract
In this work we present results of a direct search for strange quark matter (SQM) in cosmic rays with the PAMELA space spectrometer. If this state of matter exists it may be present in cosmic rays as particles, called strangelets, having a high density and an anomalously high mass-to-charge (A/Z) ratio. A direct search in space is complementary to those from ground-based spectrometers. Furthermore, it has the advantage of being potentially capable of directly identifying these particles, without any assumption on their interaction model with Earth's atmosphere and the long-term stability in terrestrial and lunar rocks. In the rigidity range from 1.0 to ∼1.0×10^{3} GV, no such particles were found in the data collected by PAMELA between 2006 and 2009. An upper limit on the strangelet flux in cosmic rays was therefore set for particles with charge 1≤Z≤8 and mass 4≤A≤1.2×10^{5}. This limit as a function of mass and as a function of magnetic rigidity allows us to constrain models of SQM production and propagation in the Galaxy.
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TIME DEPENDENCE OF THEe−FLUX MEASURED BYPAMELADURING THE 2006 JULY–2009 DECEMBER SOLAR MINIMUM. ACTA ACUST UNITED AC 2015. [DOI: 10.1088/0004-637x/810/2/142] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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PREDICTING EXTUBATION FAILURE. Intensive Care Med Exp 2015. [PMCID: PMC4798514 DOI: 10.1186/2197-425x-3-s1-a996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Enhanced venous thrombus resolution in plasminogen activator inhibitor type-2 deficient mice. J Thromb Haemost 2014; 12:1706-16. [PMID: 25041188 PMCID: PMC4194171 DOI: 10.1111/jth.12657] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2013] [Accepted: 06/30/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND The resolution of deep vein thrombosis requires an inflammatory response and mobilization of proteases, such as urokinase-type plasminogen activator (uPA) and matrix metalloproteinases (MMPs), to degrade the thrombus and remodel the injured vein wall. Plasminogen activator inhibitor type 2 (PAI-2) is a serine protease inhibitor (serpin) with unique immunosuppressive and cell survival properties that was originally identified as an inhibitor of uPA. OBJECTIVE To investigate the role of PAI-2 in venous thrombus formation and resolution. METHODS Venous thrombus resolution was compared in wild-type C57BL/6, PAI-2(-/-) , and PAI-1(-/-) mice using the stasis model of deep vein thrombosis. Formed thrombi were harvested, thrombus weights were recorded, and tissue was analyzed for uPA and MMP activities, PAI-1 expression, and the nature of inflammatory cell infiltration. RESULTS We found that the absence of PAI-2 enhanced venous thrombus resolution, while thrombus formation was unaffected. Enhanced venous thrombus resolution in PAI-2(-/-) mice was associated with increased uPA activity and reduced levels of PAI-1, with no significant effect on MMP-2 and -9 activities. PAI-1 deficiency resulted in an increase in thrombus resolution similar to PAI-2 deficiency, but additionally reduced venous thrombus formation and altered MMP activity. PAI-2-deficient thrombi had increased levels of the neutrophil chemoattractant CXCL2, which was associated with early enhanced neutrophil recruitment. CONCLUSIONS These data identify PAI-2 as a novel regulator of venous thrombus resolution, which modulates several pathways involving both inflammatory and uPA activity mechanisms, distinct from PAI-1. Further examination of these pathways may lead to potential therapeutic prospects in accelerating thrombus resolution.
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Patient-posture and Ileal-intubation during colonoscopy (PIC): a randomized controlled open-label trial. Endosc Int Open 2014; 2:E105-10. [PMID: 26135254 PMCID: PMC4423309 DOI: 10.1055/s-0034-1365541] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2013] [Accepted: 01/31/2014] [Indexed: 01/30/2023] Open
Abstract
BACKGROUND AND AIMS Patient's posture change is commonly employed by a colonoscopist to achieve complete examination. We studied whether patient's posture (left-lateral decubitus vs supine) influenced the success rate of ileal intubation. PATIENTS AND METHODS In this prospective open-label randomized study performed in the Endoscopy Suite of a tertiary-care center, all adult outpatients referred for colonoscopy, in whom cecal intubation was achieved and who satisfied predefined inclusion criteria, were randomized to undergo ileal intubation in either of the above two postures. Colonoscopy (EC-201 WL, Fujinon) was performed after overnight poly-ethylene-glycol preparation, under conscious sedation and continuous pulse-oxymetry monitoring. After confirming cecal intubation, patients were randomized for ileal intubation. Success was defined by visualization of ileal mucosa or villi (confirmed by digital photography) and was attempted until limited by pain and/or time of ≥ 6 min. RESULTS Of 320 eligible patients, 217 patients (150 males) were randomized, 106 to left-lateral decubitus and 111 to supine posture. At baseline, the two groups were evenly matched. Successful ileal intubation was achieved in 145 (66.8 %) patients overall, significantly higher in the supine posture (74.8 % versus 58.5 %; P = 0.014). On multivariate analysis, supine posture (P = 0.02), average/good right-colon preparation (P < 0.01), non-thin-lipped ileocecal (IC) valve (P < 0.001) and younger age (P = 0.02) were independent predictors of success. Positive ileal findings were recorded in 13 (9 %) patients. CONCLUSION Ileoscopy is more successful in supine than in left-lateral decubitus posture. Age, bowel preparation and type of IC valve also determine success.
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Cosmic-ray positron energy spectrum measured by PAMELA. PHYSICAL REVIEW LETTERS 2013; 111:081102. [PMID: 24010424 DOI: 10.1103/physrevlett.111.081102] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Indexed: 06/02/2023]
Abstract
Precision measurements of the positron component in the cosmic radiation provide important information about the propagation of cosmic rays and the nature of particle sources in our Galaxy. The satellite-borne experiment PAMELA has been used to make a new measurement of the cosmic-ray positron flux and fraction that extends previously published measurements up to 300 GeV in kinetic energy. The combined measurements of the cosmic-ray positron energy spectrum and fraction provide a unique tool to constrain interpretation models. During the recent solar minimum activity period from July 2006 to December 2009, approximately 24,500 positrons were observed. The results cannot be easily reconciled with purely secondary production, and additional sources of either astrophysical or exotic origin may be required.
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258 Has the age of diagnosis of cystic fibrosis related diabetes (CFRD) changed over the last 10 years? J Cyst Fibros 2013. [DOI: 10.1016/s1569-1993(13)60399-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Evaluation of a commercially available polyvinylidene fluoride membrane filtration system for water decontamination. Indian J Med Microbiol 2013; 31:97-8. [PMID: 23508447 DOI: 10.4103/0255-0857.108758] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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Measurement of the sum of WW and WZ production with W+dijet events in pp collisions at [Formula: see text]. THE EUROPEAN PHYSICAL JOURNAL. C, PARTICLES AND FIELDS 2013; 73:2283. [PMID: 25814853 PMCID: PMC4370803 DOI: 10.1140/epjc/s10052-013-2283-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 12/20/2012] [Indexed: 06/02/2023]
Abstract
A measurement of the inclusive WW+WZ diboson production cross section in proton-proton collisions is reported, based on events containing a leptonically decaying W boson and exactly two jets. The data sample, collected at [Formula: see text] with the CMS detector at the LHC, corresponds to an integrated luminosity of 5.0 fb-1. The measured value of the sum of the inclusive WW and WZ cross sections is σ(pp→WW+WZ)=68.9±8.7 (stat.)±9.7 (syst.)±1.5 (lum.) pb, consistent with the standard model prediction of 65.6±2.2 pb. This is the first measurement of WW+WZ production in pp collisions using this signature. No evidence for anomalous triple gauge couplings is found and upper limits are set on their magnitudes.
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Abstract
Intraductal papillary mucinous neoplasm (IPMN) is a distinct group of benign pancreatic neoplasms often discovered incidentally on imaging. Apart from their malignant potential, little is known about their natural history as most are surgically resected. We report an unusual presentation and possible natural history of IPMN in a patient who refused surgery and hence was on regular follow up.
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Interplay between Fe 3d and Ce 4f magnetism and Kondo interaction in CeFeAs(1-x)P(x)O probed by 75As and 31P NMR. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:135602. [PMID: 22407024 DOI: 10.1088/0953-8984/24/13/135602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
A detailed (31)P (I = 1/2) and (75)As (I = 3/2) NMR study on polycrystalline CeFeAs(1-x)P(x)O alloys is presented. The magnetism of CeFeAsO changes drastically upon P substitution on the As site. CeFePO is a heavy fermion system without long-range order whereas CeFeAsO exhibits an Fe 3d SDW type of ordering accompanied by a structural transition from tetragonal (TT) to orthorhombic (OT) structure. Furthermore, Ce 4f(1) orders antiferromagnetically (AFM) at low temperature. At the critical concentration where the Fe magnetism is diminished the Ce-Ce interaction changes to a ferromagnetic (FM) type of ordering. Three representative samples of the CeFeAs(1-x)P(x)O (x = 0.05, 0.3 and 0.9) series are systematically investigated. (1) For the x = 0.05 alloy a drastic change of the linewidth at 130 K indicates the AFM-SDW type of ordering of Fe and the structural change from the TT to the OT phase. The linewidth roughly measures the internal field in the ordered state and the transition is most likely first order. The small and nearly constant shift from (31)P and (75)As NMR suggests the presence of competing hyperfine interactions between the nuclear spins and the 4f and 3d ions of Ce and Fe. (2) For the x = 0.3 alloy, the evolution of the Fe-SDW type of order takes place at around 70 K corroborating the results of bulk measurement and μSR. Here we found evidence for phase separation of paramagnetic and magnetic SDW phases. (3) In contrast to the heavy fermion CeFePO for the x = 0.9 alloy a phase transition is found at 2 K. The field-dependent NMR shift gives evidence of FM ordering. Above the ordering the spin-lattice relaxation rate (31)(1/T(1)) shows unconventional, non-Korringa-like behaviour which indicates a complex interplay of Kondo and FM fluctuations.
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Magnetism and superconductivity in Eu0.2Sr0.8(Fe0.86Co0.14)2As2 probed by 75As NMR. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2012; 24:045702. [PMID: 22214818 DOI: 10.1088/0953-8984/24/4/045702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We report bulk superconductivity (SC) in Eu(0.2)Sr(0.8)(Fe(0.86)Co(0.14))(2)As(2) single crystals by means of electrical resistivity, magnetic susceptibility and specific heat measurements with T(c) is approximately equal to 20 K and an antiferromagnetic (AFM) ordering of Eu(2+) moments at T(N) is approximately equal to 2.0 K in zero field. (75)As NMR experiments have been performed in the two external field directions (H is parallel to ab) and (H is parallel to c). (75)As-NMR spectra are analysed in terms of first-order quadrupolar interaction. Spin-lattice relaxation rates (1/T(1)) follow a T(3) law in the temperature range 4.2-15 K. There is no signature of a Hebel-Slichter coherence peak just below the SC transition, indicating a non-s-wave or s(±) type of superconductivity. In the temperature range 160-18 K 1/T(1)T follows the C/(T+θ) law reflecting 2D AFM spin fluctuations.
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