Heat treatment effect on the structural, morphological, and optical properties of plasma polymerized furan-2-carbaldehyde thin films

The furan-2-carbaldehyde (PPFCD) amorphous polymer thin films, with several thicknesses, were deposited onto glass substrates using a glow discharge of monomer FCD at ordinary room temperature via plasma polymerization technique. The structural, morphological, and optical characteristics of the as synthesised PPFCD amorphous films were studied as a function of temperature via X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), and ultraviolet-visible (UV–Vis) absorption spectroscopy. The amorphous nature of the thin films was ascertained in both as-synthesised and heat treated states using the XRD studies. The SEM micrographs display homogeneous and fracture free surface of PPFCD films and no remarkable variation in the surface morphology of the as synthesised films was detected owing to the heat treatment procedure. However, the EDX, and FTIR analysis represented some structural rearrangement originated from the heat treatment of the PPFCD thin films. The analysis of the UV–Vis absorption spectroscopy revealed that the absorbance of the films depend on the films thickness and the temperature of the heat treatment. The optical band-gaps of PPFCD amorphous films were found to be significantly decreased with the gradual rise in heat treatment temperature

Structural and optical properties of plasma polymerized pyromucic aldehyde thin films

Abstract: Plasma polymerized pyromucic aldehyde (PPPA) thin films have been deposited on to glass substrates by glow discharge technique. Scanning electron microscopy (SEM) graphs reveal that the surface morphology of PPPA thin films is uniform and flawless. FTIR analysis reveals that the chemical composition of PPPA films is different from that of the pyromucic aldehyde (PA). From the UV-vis spectra direct and indirect transition energy gaps were determined for as deposited PPPA thin films of different thicknesses

Convalescent plasma in patients admitted to hospital with COVID-19 (RECOVERY): a randomised controlled, open-label, platform trial

Background: Many patients with COVID-19 have been treated with plasma containing anti-SARS-CoV-2 antibodies. We aimed to evaluate the safety and efficacy of convalescent plasma therapy in patients admitted to hospital with COVID-19. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. The trial is underway at 177 NHS hospitals from across the UK. Eligible and consenting patients were randomly assigned (1:1) to receive either usual care alone (usual care group) or usual care plus high-titre convalescent plasma (convalescent plasma group). The primary outcome was 28-day mortality, analysed on an intention-to-treat basis. The trial is registered with ISRCTN, 50189673, and ClinicalTrials.gov, NCT04381936. Findings: Between May 28, 2020, and Jan 15, 2021, 11558 (71%) of 16287 patients enrolled in RECOVERY were eligible to receive convalescent plasma and were assigned to either the convalescent plasma group or the usual care group. There was no significant difference in 28-day mortality between the two groups: 1399 (24%) of 5795 patients in the convalescent plasma group and 1408 (24%) of 5763 patients in the usual care group died within 28 days (rate ratio 1·00, 95% CI 0·93–1·07; p=0·95). The 28-day mortality rate ratio was similar in all prespecified subgroups of patients, including in those patients without detectable SARS-CoV-2 antibodies at randomisation. Allocation to convalescent plasma had no significant effect on the proportion of patients discharged from hospital within 28 days (3832 [66%] patients in the convalescent plasma group vs 3822 [66%] patients in the usual care group; rate ratio 0·99, 95% CI 0·94–1·03; p=0·57). Among those not on invasive mechanical ventilation at randomisation, there was no significant difference in the proportion of patients meeting the composite endpoint of progression to invasive mechanical ventilation or death (1568 [29%] of 5493 patients in the convalescent plasma group vs 1568 [29%] of 5448 patients in the usual care group; rate ratio 0·99, 95% CI 0·93–1·05; p=0·79). Interpretation: In patients hospitalised with COVID-19, high-titre convalescent plasma did not improve survival or other prespecified clinical outcomes. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Tocilizumab in patients admitted to hospital with COVID-19 (RECOVERY): a randomised, controlled, open-label, platform trial

Background: In this study, we aimed to evaluate the effects of tocilizumab in adult patients admitted to hospital with COVID-19 with both hypoxia and systemic inflammation. Methods: This randomised, controlled, open-label, platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]), is assessing several possible treatments in patients hospitalised with COVID-19 in the UK. Those trial participants with hypoxia (oxygen saturation <92% on air or requiring oxygen therapy) and evidence of systemic inflammation (C-reactive protein ≥75 mg/L) were eligible for random assignment in a 1:1 ratio to usual standard of care alone versus usual standard of care plus tocilizumab at a dose of 400 mg–800 mg (depending on weight) given intravenously. A second dose could be given 12–24 h later if the patient's condition had not improved. The primary outcome was 28-day mortality, assessed in the intention-to-treat population. The trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936). Findings: Between April 23, 2020, and Jan 24, 2021, 4116 adults of 21 550 patients enrolled into the RECOVERY trial were included in the assessment of tocilizumab, including 3385 (82%) patients receiving systemic corticosteroids. Overall, 621 (31%) of the 2022 patients allocated tocilizumab and 729 (35%) of the 2094 patients allocated to usual care died within 28 days (rate ratio 0·85; 95% CI 0·76–0·94; p=0·0028). Consistent results were seen in all prespecified subgroups of patients, including those receiving systemic corticosteroids. Patients allocated to tocilizumab were more likely to be discharged from hospital within 28 days (57% vs 50%; rate ratio 1·22; 1·12–1·33; p<0·0001). Among those not receiving invasive mechanical ventilation at baseline, patients allocated tocilizumab were less likely to reach the composite endpoint of invasive mechanical ventilation or death (35% vs 42%; risk ratio 0·84; 95% CI 0·77–0·92; p<0·0001). Interpretation: In hospitalised COVID-19 patients with hypoxia and systemic inflammation, tocilizumab improved survival and other clinical outcomes. These benefits were seen regardless of the amount of respiratory support and were additional to the benefits of systemic corticosteroids. Funding: UK Research and Innovation (Medical Research Council) and National Institute of Health Research

Synthesis and aging effect of plasma-polymerized 2-furancarboxaldehyde amorphous thin films

Monomer 2-Furancarboxaldehyde (FCD) deposited via glow discharge technique onto glass substrates to produce plasma synthesized 2-Furancarboxaldehyde (PPFCD) thin films with different thicknesses. The various characteristics, such as the structural, optical, morphological and elemental properties of unaged (as deposited) as well as aged PPFCD thin films were studied using Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), ultraviolet-visible (UV-Vis) absorption spectroscopy, environmental scanning electron microscopy (ESEM), and energy dispersive X-ray spectroscopic (EDAX) methods. The XRD studies indicated the existence of small crystallite domains or amorphous nature of the PPFCD films. The ESEM micrographs exhibited the uniform, pinhole, and fracture free surface of PPFCD films together with no queerish morphological variations due to the aging effect. On the contrary, the EDAX and FTIR spectroscopic studies illustrated some structural rearrangement owing to the aging of PPFCD thin films. The UV-Vis studies revealed that the direct and indirect optical band gaps (Edb and Eib), and steepness parameter (σ) of the aged PPFCD films were significantly reduced from 3.43 to 3.20 eV, 2.18 to 1.53 eV, and 0.0546 to 0.0524 respectively while the Urbach energy (Eu) value was slightly enhanced from 0.48 to 0.50 eV. This indicated that the aging has remarkable effects on the optical properties of the PPFCD films

Understanding the enhancement of the optical and electronic attributes of iodine-doped vacuum deposited tetramethylaniline (PPTMA) thin film coatings

This article presents a comprehensive analysis on vacuum deposited Iodine-doped plasma polymerized monomer N, N, 3, 5 tetramethylanilin (PPTMA) thin film coatings to comprehend the structural, morphological, chemical, optical, and electronic properties. The as-deposited PPTMA thin film coatings were characterized by means of X-ray diffraction (XRD), infrared spectroscopy (IR), scanning electron microscopy (SEM), energy dispersive X-ray (EDAX) spectroscopy, and ultraviolet-visible spectrophotometry, respectively. The amorphous nature of the PPTMA thin film coatings was established via XRD analysis. The surfaces of the PPTMA thin film coatings were observed to be smooth and uniform. The IR studies pointed out that the I-atoms get connected to amine nitrogen sites of the TMA structure. The absorption peaks detected at 1683 and 1577 cm−1 indicated the existence of aromatic ring stretching, and the Csingle bondC stretched vibrations due to the I-doping into the PPTMA thin film coatings. It was further noticed that the iodine doping resulted the Nsingle bondH, Csingle bondN stretching vibrations shifting towards higher wave number sides of 3384 cm−1, and 1384 cm−1 respectively. In a similar fashion, the optical absorption peaks were also shifted towards the longer wavelength sides (from 300 nm to 380 nm). The direct energy band gaps of the PPTMA coatings were decreased 3.20–3.04 eV with increasing I-content. Similar types of behaviors were also observed for the indirect energy band-gaps and Urbach energy values of the PPTMA thin film coatings. However, the refractive index, high frequency dielectric constant, and static dielectric constant were gradually increased with the monotonic increase of coatings thickness due to subsequently enhanced I-content

A holistic framework towards understanding the optical and dielectric behaviors of CH3NH3PbCl3 perovskites/graphene oxide hybrid films for light absorbing active layer

In this work methylammonium trichloride CH3NH3Cl3 (MACl), methylammonium lead trichloride CH3NH3PbCl3 (MAPbCl), and graphene oxide (GO) doped methylammonium lead trichloride GO-CH3NH3PbCl3 (MAPbCl:GO) perovskite based thin film coatings deposited onto glass substrates using wet-chemical based spin coating technique at varying GO concentrations (0.025, 0.050, 0.075 ​g/ml), were investigated for their structural, compositional, optical, and dielectric characteristics. Characterizations of the coatings were carried out using XRD, SEM, FTIR, and UV–Vis spectroscopic methods. The XRD patterns and scanning electron microscope images revealed the cubic and regular constructions of MAPbCl and MAPbCl:GO with higher degree of crystallinity. FTIR studies demonstrated different vibrational modes mainly dominated by the organic salt (MACl) in both structures and a few new bonds such as Cdouble bondC stretching, C–H (methyl) bending, CH3–NH3 rocking were observed. Effective changes in the band-gap values were observed due to GO incorporation. A good correlation among different optical parameter such as absorption coefficient, refractive index, extinction coefficient, and dielectric function was also pragmatic. A very high value of the optical conductivity of 2.02 ​× ​1014 ​Ω/nm was shown by MAPbCl:GO (0.05 ​g/ml) perovskite composite. Hence, MAPbCl:GO coatings could be successfully used as a good light absorbing layer in perovskite solar cell (PSC) in an open-air environment and may be explored for further development to achieve a stable structure

Clinical and immunological aspects of post–kala-azar dermal leishmaniasis in Bangladesh

We conducted active surveillance for kala-azar and post–kala-azar dermal leishmaniasis (PKDL) in a population of 24,814 individuals. Between 2002 and 2010, 1,002 kala-azar and 185 PKDL cases occurred. Median PKDL patient age was 12 years; 9% had no antecedent kala-azar. Cases per 10,000 person-years peaked at 90 for kala-azar (2005) and 28 for PKDL (2007). Cumulative PKDL incidence among kala-azar patients was 17% by 5 years. Kala-azar patients younger than 15 years were more likely than older patients to develop PKDL; no other risk factors were identified. The most common lesions were hypopigmented macules. Of 98 untreated PKDL patients, 48 (49%) patients had resolution, with median time of 19 months. Kala-azar patients showed elevated interferon-γ (IFNγ), tumor necrosis factor-α (TNFα), and interleukin 10 (IL-10). Matrix metalloproteinase 9 (MMP9) and MMP9/tissue inhibitor of matrix metalloproteinase-1 (TIMP1) ratio were significantly higher in PKDL patients than in other groups. PKDL is frequent in Bangladesh and poses a challenge to the current visceral leishmaniasis elimination initiative in the Indian subcontinent