COVID-19 Survivors’ Reports of the Timing, Duration, and Health Impacts of Post-Acute Sequelae of SARS-CoV-2 (PASC) Infection

IMPORTANCE Post-Acute Sequelae of SARS-CoV-2 Infection (PASC) is a major public health concern. Studies suggest that 1 in 3 infected with SARS-CoV-2 may develop PASC, including those without initial symptoms or with mild COVID-19 disease.1, 2 OBJECTIVE To evaluate the timing, duration, and health impacts of PASC reported by a large group of primarily non-hospitalized COVID-19 survivors. DESIGN, SETTING, AND PARTICIPANTS A survey of 5,163 COVID-19 survivors reporting symptoms for more than 21 days following SARS-CoV-2 infection. Participants were recruited from Survivor Corps and other online COVID-19 survivor support groups. MAIN OUTCOMES AND MEASURES Participants reported demographic information, as well as the timing, duration, health impacts, and other attributes of PASC. The temporal distribution of symptoms, including average time of onset and duration of symptoms were determined, as well as the perceived distress and impact on ability to work. RESULTS On average, participants reported 21.4 symptoms and the number of symptoms ranged from 1 to 93. The most common symptoms were fatigue (79.0%), headache (55.3%), shortness of breath (55.3%), difficulty concentrating (53.6%), cough (49.0%), changed sense of taste (44.9%), diarrhea (43.9%), and muscle or body aches (43.5%). The timing of symptom onset varied and was best described as happening in waves. The longest lasting symptoms on average for all participants (in days) were “frequently changing” symptoms (112.0), inability to exercise (106.5), fatigue (101.7), difficulty concentrating (101.1), memory problems (100.8), sadness (99.2), hormone imbalance (99.1), and shortness of breath (96.9). The symptoms that affected ability to work included the relapsing/remitting nature of illness (described by survivors as “changing symptoms”), inability to concentrate, fatigue, and memory problems, among others. Symptoms causing the greatest level of distress (on scale of 1 “none” to 5 “a great deal”) were extreme pressure at the base of the head (4.4), syncope (4.3), sharp or sudden chest pain (4.2), brain pressure (4.2), headache (4.2), persistent chest pain or pressure (4.1), and bone pain in extremities (4.1). CONCLUSIONS AND RELEVANCE PASC is an emerging public health priority characterized by a wide range of changing symptoms, which hinder survivors’ ability to work. PASC has not been fully characterized and the trajectory of symptoms and long-term outcomes are unknown. There is no treatment for PASC, and survivors report distress in addition to a host of ongoing symptoms. Capturing patient reports of symptoms through open-ended inquiry is a critical first step in accurately and comprehensively characterizing PASC to ensure that medical treatments and management strategies best meet the needs of individual patients and help mitigate health impacts of this new disease

Enzyme production from food wastes using a biorefinery concept

According to Food and Agricultural Organization (FAO), one-third of food produced globally for human consumption (nearly 1.3 billion tonnes) is lost along the food supply chain. In many countries food waste is currently landfilled or incinerated together with other combustible municipal wastes for possible recovery of energy. However, these two options are facing more and more economic and environmental stresses. Due to its organic- and nutrient-rich nature, theoretically food waste can be converted to valuable products (e.g. bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals and fuels) through various fermentation processes. Such conversion of food waste is potentially more profitable than its conversion to animal feed or transportation fuel. Food waste valorisation has therefore gained interest, with value added bio-products such as methane, hydrogen, ethanol, enzymes, organic acids, chemicals, and fuels. Therefore, the aim of this review is to provide information on the food waste situation with emphasis on Asia–Pacific countries and the state of the art food waste processing technologies to produce enzymes

Electroluminescence of CdS nanoparticles-polyvinyl carbazole composites

157-160In the present study thin films of CdS nanoparticle-polyvinyl carbazole (PVK) composite have been prepared using chemical method. The absorption spectra and electroluminescence of the films doped with different concentrations of CdS nanoparticle have been measured. The absorption of pure PVK film starts at 290 nm wavelength in which a peak appears at 270 nm, indicating that the optical energy gap of PVK film is 4.26 eV. The absorption onset of CdS-PVK thin films is obtained at 300 nm, which gives the band gap of CdS nanoparticles as 4.13 eV. It is observed that the current varies linearly, whereas EL intensity varies non-linearly with increasing voltage. At a particular frequency, the emission starts at a particular threshold voltage and then it increases rapidly with increasing voltage. At a particular frequency and voltage, the EL intensity of the composite increases with concentration of CdS nanoparticles in PVK polymer and attains saturation at 5% CdS concentration. It is shown that the EL of CdS-PVK composites can be explained on the basis of electron acceleration-collision mechanism

Temperature dependence of exciton life-time in GaAs/ AIGaAs quantum wells

719-722In GaAs/AJGaAs quantum well structures, the confinement of electrons as well as, holes in GaAs well region causes enhancement of Coulomb interaction, which leads to formation of excitons with large binding energy, and, therefore, excitonic states persist even up to room temperature. The phenomenon of photoluminescence (PL) in such structures is dominated by radiative recombination of excitons. The PL and PL decay time is found to depend on temperature. At higher temperatures, thermal population of higher excitonic sub-bands and exciton ionization also need to be considered. The temperature dependence of radiative and non-radiative exciton life-times have been formulated. The nonlinear behaviour of temperature dependence of total life-time of exciton or the PL decay time has been indicated. At low temperatures, exciton decay is mainly due to radiative processes whereas at higher temperatures, it is by non-radiative channels. Therefore, the life-time of exciton, initially, increases with temperature, attains a maximum value and then decreases at high temperatures. The processes different from radiative free exciton recombination also play an important role and possibly, dominate the recombination mechanism as the temperature is raised

Excitation and emission spectra of anti-Stokes luminescence of Tm³⁺ in glass <span style="font-size:14.0pt;line-height:115%;font-family:"Times New Roman"; mso-fareast-font-family:"Times New Roman";color:black;mso-ansi-language:EN-IN; mso-fareast-language:EN-IN;mso-bidi-language:HI" lang="EN-IN">ceramics doped with various concentrations of sensitizer</span>

136-141In certain rare-earth doped glass ceramics luminescence emission has been observed at wavelength shorter than the exciting wavelength. This is known as anti-Stokes luminescence or up-conversion, which is due to accumulation of excitation energy by rare-earth ions. In Tm3+ and Yb3+ doped glass ceramics, Tm3+ acts as an activator and Yb3+ acts as a sensitizer. The activator concentration was kept constant at 0.2 mol% and the sensitizer Yb3+ concentration was varied from 0.0 mol% to 20 mol%. In emission spectra of glass ceramics doped with Tm3+ and Yb3+, under infrared excitation (966 nm) one peak of high intensity was found at different wavelengths between 400 to 500 nm for different concentrations of sensitizer. The peak is slightly shifted towards shorter wavelength with increasing concentrations of the sensitizer. This reveals that 3-photon up-conversion is prominent and presence of Yb3+ ions slightly shifts the energy levels of Tm3+. In the excitation spectra of glass ceramics doped with Yb3+ and Tm3+ , initially the emission intensity increases with increasing wavelength, attains an optimum value for 920 nm, 930 nm, 950 nm and 960 nm and then it decreases with further increase in the wavelength. These photon energies may correspond to energy difference between levels of Tm3+ or Yb3+. Both in the excitation spectra and emission spectra, initially the anti-Stokes luminescence intensity increases with sensitizer concentration, attains an optimum value and then it decreases with further increase in the sensitizer concentration. </span

The other COVID-19 survivors: Timing, duration, and health impact of post-acute sequelae of SARS-CoV-2 infection.

Aims and objectivesTo determine the frequency, timing, and duration of post-acute sequelae of SARS-CoV-2 infection (PASC) and their impact on health and function.BackgroundPost-acute sequelae of SARS-CoV-2 infection is an emerging major public health problem that is poorly understood and has no current treatment or cure. PASC is a new syndrome that has yet to be fully clinically characterised.DesignDescriptive cross-sectional survey (n&nbsp;=&nbsp;5163) was conducted from online COVID-19 survivor support groups who reported symptoms for more than 21 days following SARS-CoV-2 infection.MethodsParticipants reported background demographics and the date and method of their covid diagnosis, as well as all symptoms experienced since onset of covid in terms of the symptom start date, duration, and Likert scales measuring three symptom-specific health impacts: pain and discomfort, work impairment, and social impairment. Descriptive statistics and measures of central tendencies were computed for participant demographics and symptom data.ResultsParticipants reported experiencing a mean of 21 symptoms (range 1-93); fatigue (79.0%), headache (55.3%), shortness of breath (55.3%) and difficulty concentrating (53.6%) were the most common. Symptoms often remitted and relapsed for extended periods of time (duration M&nbsp;=&nbsp;112 days), longest lasting symptoms included the inability to exercise (M&nbsp;=&nbsp;106.5 days), fatigue (M&nbsp;=&nbsp;101.7 days) and difficulty concentrating, associated with memory impairment (M&nbsp;=&nbsp;101.1 days). Participants reported extreme pressure at the base of the head, syncope, sharp or sudden chest pain, and "brain pressure" among the most distressing and impacting daily life.ConclusionsPost-acute sequelae of SARS-CoV-2 infection can be characterised by a wide range of symptoms, many of which cause moderate-to-severe distress and can hinder survivors' overall well-being.Relevance to clinical practiceThis study advances our understanding of the symptoms of PASC and their health impacts