In vitro evaluation of commercial probiotic products used for marine shrimp cultivation in Thailand

The objective of this study was to evaluate the effectiveness of 12 commercial probiotic products in Thailand, used in marine shrimp cultivation, based on two criteria namely, accuracy of the information on product labels as regards the number and types of microorganisms and acceptability of the number of probiotic microorganisms at 10,sup>6 colony forming unit (CFU)/g in the products. Of the 12 products sampled, only two of them provided adequate information on the number and composition of microorganisms and their proper dosage. In addition, none of the probiotic products possessed the correct number and composition of microorganisms or qualitative extracellular enzymes, declared on their labels nor did they show any in vitro inhibitory activity on shrimp pathogenic Vibrio harveyi. However, a few products were capable of biosynthesis of amylase, protease and lipase with high capacities.Key words: Commercial probiotic product, marine shrimp, Vibrio harveyi, amylase, protease, lipase

The Neurological Complexities and Prognosis of COVID-19

Several neurological manifestations and complications linked to SARS-CoV-2 have been reported along with well-known respiratory pathology. The global active transmission of SARS-CoV-2 and its unexplained characteristics has led to a pandemic. Since its rapid emergence from Wuhan, China, in December 2019, several studies have reported the impacts of COVID-19 on the CNS and PNS and its implications. This comprehensive review article comprises case reports, case series, metaanalysis, cohort studies, retrospective studies, and narrative reviews focusing on COVID-19-associated CNS and PNS complexities. The authors searched for over 200 articles and used 52 publications related to the neurological complexities of COVID-19 affecting the CNS and PNS as part of the literature review process. The predominant CNS symptoms noted in COVID-19 patients were headaches and dizziness, and the most common PNS symptoms were alterations in smell and taste. Case reports on headache/dizziness, intracerebral hemorrhage, acute hemorrhagic necrotizing encephalopathy, meningitis/encephalitis, encephalopathy, cerebrovascular events, chemosensory dysfunction, Guillain-Barre syndrome, and acute transverse myelitis/acute necrotizing myelitis in PCR-confirmed SARS-CoV-2 subjects are also reported. New-onset neurological symptoms were also observed in children with PCR-confirmed SARS-CoV-2 that developed pediatric multisystem inflammatory syndrome (PIMS). This comprehensive review article will assist the clinicians and researchers to gain information about the neurological manifestations and complications associated with COVID-19 and develop planning to treat these symptoms in concerned patients of all ages. However, it is unclear whether SARS-CoV2-associated neurological effects are due to primary infections or secondary response to the possible mechanisms discussed in this review

Tozinameran (BNT162b2) Vaccine: The Journey from Preclinical Research to Clinical Trials and Authorization

Vaccination development and production was an essential question for the prevention and global control of COVID-19. The strong support from governing authorities such as Operation Warp Speed and robust funding has led to the development and authorization of the tozinameran (BNT162b2) vaccine. The BNT162b2 vaccine is a lipid nanoparticle-encapsulated mRNA that encodes for SARS-CoV-2 spike protein, the main site for neutralizing antibodies. Once it binds with the host cells, the lipid nanoparticles enable the transfer of the RNA, causing S antigens\u27 expression of the SARS-CoV-2, conferring immunity. The vaccine is administered as a 2-dose regime 21 days apart for individuals 16 years and older. Pfizer-BioNTech\u27s BNT162b2 vaccine was the first candidate to receive FDA-Emergency Use Authorization (EUA) on December 11, 2020. During phase 2/3 clinical trials, 95% efficacy was reported among 37,706 participants over the age of 16 who received the BNT162b2 vaccination; additionally, 52% efficacy was noted 12 days following the administration of the first dose of BNT162b2, reflecting early protection of COVID-19. The BNT162b2 vaccine has exhibited 100% efficacy in clinical trials of adolescents between the ages of 12 and 15. Clinical trials in pregnant women and children under the age of 12 are expected to also exhibit promising results. This review article encompasses tozinameran (BNT162b2) vaccine journey, summarizing the BNT162b1 and BNT162b2 vaccines from preclinical studies, clinical trial phases, dosages, immune response, adverse effects, and FDA-EUA

Exploring the Graft-To Synthesis of All-Conjugated Comb Copolymers Using Azide–Alkyne Click Chemistry

Copolymers with graft architectures possess interesting material properties distinct from their linear polymer counterparts. The effects of multidimensional architectures on the optoelectronic and physical properties of all-conjugated graft copolymers are not well-known, thus providing a large incentive for their study. In order to readily access these materials (hypothesized to have “comb” architectures), it is extremely important to investigate the methods used in their synthesis. Here we study the graft-to synthesis of comb copolymers composed of polythiophene backbones and polyselenophene side chains and identify the opportunities and challenges associated with copolymer formation. Azide-functionalized polythiophene “backbones” and acetylene-terminated polyselenophene “side chains” were synthesized in a controlled fashion using Kumada catalyst-transfer polycondensation (KCTP) polymerization and grafted together using copper-catalyzed azide–alkyne click chemistry (CuAAC). ¹H NMR, GPC, and FTIR results confirm the attachment of polyselenophene side chains to the polythiophene backbone, resulting in comb copolymers with varying grafting densities. Low grafting density copolymers are readily synthesized using various backbone and side chain polymers. Midrange grafting density copolymers are more challenging but can be accessed when the availability of the graft sites on the polythiophene backbones is maximized. The synthesis of high grafting density combs remains challenging even when various modifications to the backbone and side chain polymers are implemented to improve the grafting efficiency. Problematic Glaser homocoupling of acetylene-terminated polyselenophenes was observed in certain conditions; however, this can be successfully prevented using an organic-soluble copper catalyst which is broadly applicable to many polymer–polymer CuAAC reactions. Ultimately, this investigation demonstrates a graft-to synthetic method that is useful for low- and midgrafting density all-conjugated comb copolymers, thus providing a means to further the study of these interesting multidimensional semiconducting materials

Synthesis of Macrocyclic Poly(3-hexylthiophene) and Poly(3-heptylselenophene) by Alkyne Homocoupling

Here we report the synthesis of cyclic samples of poly­(3-hexylthiophene) (P3HT, degrees of polymerization = 25, 40, and 75) and poly­(3-heptylselenophene) (P37S, DP = 30). Cyclization was accomplished using a mild alkyne–alkyne homocoupling procedure. Alkyne-terminated poly­(ethylene glycol) was then coupled to residual uncyclized polymers, which were subsequently removed by column chromatography, enabling isolation and characterization of pure cyclic polymers. Cyclization was confirmed by the disappearance of terminal alkyne protons, the decrease in hydrodynamic radius [measured by size exclusion chromatography (SEC)], and the observed identical molecular weight distribution [measured by matrix-assisted laser desorption/ionization (MALDI) mass spectrometry]. The lower weight macrocyclic polymers have decreased self-assembly as measured by optical absorption and transmission electron microscopy. The highest weight macrocycles were imaged using scanning tunneling microscopy. Cyclic polymers adopted a tightly bent conformation, while their linear analogues assembled as fully extended chains. Our method of cyclization and purification is broadly applicable to conjugated polymers (CPs) and will enable the development of novel optoelectronic materials